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Future marine ecosystem drivers, biodiversity, and fisheries maximum catch potential in Pacific Island countries and territories under climate change
Abstract
The increase in anthropogenic CO2 emissions over the last century has modified oceanic conditions, affecting
marine ecosystems and the goods and services that they provide to society. Pacific Island countries and territories
are highly vulnerable to these changes because of their strong dependence on ocean resources, high level
of exposure to climate effects, and low adaptive capacity. Projections of mid-to-late 21st century changes in sea
surface temperature (SST), dissolved oxygen, pH, and net primary productivity (NPP) were synthesized across
the tropical Western Pacific under strong climate mitigation and business-as-usual scenarios. These projections
were used to model impacts on marine biodiversity and potential fisheries catches. Results were consistent across
three climate models, indicating that SST will rise by ≥ 3 °C, surface dissolved oxygen will decline by ≥
0.01 ml L−1, pH will drop by ≥ 0.3, and NPP will decrease by 0.5 g m−2 d−1 across much of the region by 2100
under the business-as-usual scenario. These changes were associated with rates of local species extinction of >
50% in many regions as fishes and invertebrates decreased in abundance or migrated to regions with conditions
more suitable to their bio-climate envelope. Maximum potential catch (MCP) was projected to decrease by >
50% across many areas, with the largest impacts in the western Pacific warm pool. Climate change scenarios that
included strong mitigation resulted in substantial reductions of MCP losses, with the area where MCP losses
exceeded 50% reduced from 74.4% of the region under business-as-usual to 36.0% of the region under the strong
mitigation scenario.
... The effects of climate change on marine species in the NWP are still inadequately documented. The information deficit is concerning, as this region is among the most rapidly warming areas of the world ocean (Palmer et al., 2017) and harbors remarkable biodiversity of marine species endangered by climate change (Asch et al., 2018). Moreover, prolonged periods of intensive fishing have led to the depletion of numerous stocks to unsustainable biological levels in different parts of the Pacific. ...
... Alterations in community composition can result in significant ecological and social implications (Asch et al., 2018). The likelihood of species invasion is greater at high latitudes, while species extirpation predominates at low latitudes (Hu et al., 2022). ...
... Species richness is anticipated to decline more frequently in the Indo-Pacific region and semi-enclosed seas, such as the southwest Taiwan, compared to other regions (Huang et al., 2016). The transmission of this effect to the catch indicates that cold temperate countries may benefit from these changes, whereas tropical countries could experience adverse impacts (Asch et al., 2018). The current study in Taiwan indicates that catch rates of moonfish may rise in the future as projected from the RCPs (Figure 8) pointing towards an increased abundance of moonfish which may happen if larger predatory fishes migrate to other areas due to changing ocean conditions. ...
Introduction
Prior research emphasizes the beneficiaries and detractors in fisheries due to climate change, focusing on alterations in biomass, species mix, and potential yields. Comprehending the potential impact of climate change on the fisheries income of maritime nations is an essential subsequent step in formulating effective socio-economic policies and food sustainability plans to mitigate and adapt to climate change. Globally, our understanding of small-scale fisheries remains inadequate, despite their significance for food security and livelihoods.
Methods
This study demonstrates by using global circulation model (GCM: IPSL) that moonfish catches react favorably to climate alterations in southwest Taiwan, through the analysis of primary fishery data from 2014-2020 spanning two seasons – northeast and southwest monsoons by using generalized additive models. The anticipated habitat shifts were utilized to examine the impact of future environmental changes on moonfish catch rates.
Result
By the 2060s, moonfish emerged as a winner of climate change in this study region. The habitats of moonfish are projected to shift westward during southwest monsoon, with a mean habitat centroid displacement of about 50-150 Km between RCP 2.6 and 8.5 during NE monsoon while 20-40 Km during the SW monsoon. A possible explanation could be that the Taiwan Strait (TS) may serve as a geographical barrier to the northward migration of south-dwelling moonfish. The study further demonstrates that moonfish fisheries catch rates may increase by 22.5% and 17.2% beyond the present catch rates by the 2060s under elevated CO2 emission scenarios during northeast and southwest monsoons respectively.
Discussion
Our findings indicate the necessity for comprehensive economic evaluations regarding the potential impacts of climate change on regional small-scale marine fisheries, contributing to the adaptive conservation and management of fish habitats.
... Scientists predict that if the situation continues, plankton and fish populations will decline by 50-90% in the next five decades, which could turn the Indian Ocean into an ecological desert and no longer productive (Roxy et al., 2016). By the end of the 21 st century, temperatures in the tropical Pacific will increase by more than 3°C, which could dramatically reduce marine biodiversity by threatening 50-80% of marine species, especially plankton (Asch et al., 2018). In addition, the most valuable species in the Canadian Pacific Ocean, Northwest Pacific Ocean, Yellow Sea and East China Sea continue to decline due to climate change (Ma et al., 2019;Talloni-Alvarez et al., 2019). ...
... Several studies describe the potential impacts of climate change on coastal biodiversity and marine ecosystems (Asch et al., 2018;Häder & Barnes, 2019;Baltar et al., 2019;Mclean et al., 2018;Christensen, 2019;Priya et al., 2023;Tregarot et al., 2024). Some studies use statistical analysis to investigate the potential impacts (Speers et al., 2016;Brierley & Kingsford, 2009;Chapman et al., 2020). ...
... If this situation continues, about 80% to 90% of the biodiversity of marine ecosystems may eventually be lost by the end of this century. For example, Asch et al. (2018) theoretically described the effects of global warming on the aquatic biodiversity of the Pacific Ocean. They showed that if global warming continues at this rate, atmospheric temperatures will increase by at least 3 0 C by the end of this century, which can severely damage 50% to 74% of aquatic biodiversity by reducing dissolved oxygen and pH levels in seawater. ...
This book investigates the potential impacts of global warming and rapid GHG emissions from artificial sources on coastal and marine ecosystems and introduces effective strategies to improve coastal and marine ecosystems by mitigating GHG emissions and concentrations. Therefore, this book develops four novel mathematical models to investigate the potential impacts on coastal and marine ecosystems, and two novel optimal control problems to mitigate the potential impacts and improve coastal and marine ecosystems by reducing GHG emissions and concentrations. All models are extensively validated by theoretical analysis and numerical simulations. The main objective of this book is to be aware of the adverse effects of rapid GHG emissions and global warming on the environment and all life on earth, to reveal how to maintain a healthy environment for all life, and to save our beautiful planet from ecological deserts.
The book discloses applications of mathematical modeling for environmental management in environmental science and applied mathematics. It provides new concepts and methods for scientists who study and develop mathematical modeling and environmental science, and researchers who apply them to solve real-life problems.
... Climate variability has a wide variety of documented impacts on marine species, but sea water temperature continues to be an important driver of change in marine environments for both populations and individuals. Temperature is a primary component of many climate variability indices like the MEI (Wolter and Timlin 2011), and the impacts of rising temperatures are also a main result of anthropogenically induced climate change (Pörtner and Peck 2010;Asch et al. 2018). We found that local drivers in the form of latitude-specific SST were the best predictors of N. unicornis growth rate in this region, rather than broader regional drivers as often reported in the literature (Black et al. 2009;Morrongiello et al. 2012;Ong et al. 2018). ...
... Furthermore, this study highlights the need for long-term data collection efforts in remote regions of the world, which are difficult and costly to access, but are often among the most vulnerable to impacts of climate change. Changing environmental conditions associated with anthropogenically induced climate change are predicted to have negative impacts on reef-associated fishes and fisheries in localized coastal areas of the western tropical Pacific (Asch et al. 2018). As the frequency of extreme El Niño events is expected to double under the current Paris target of 1.5 °C (Guojian et al. 2017), future ENSO events are the primary concern in the USAPI (Chowdhury et al. 2022). ...
Understanding how environmental stressors impact fisheries is imperative for the sustainable management of our marine resources. Synchrony in inter-annual growth patterns among individuals and populations has been identified across large spatial scales, both within and among species. This synchrony indicates a detectable sensitivity to changes in climatic or environmental conditions. We explored within-region effects of environmental and climatic variability using inter-annual otolith growth rates (increments) in a tropical coral reef fish, Naso unicornis. Dendrochronology techniques were applied to remove age-specific growth effects and extract a high-frequency variability signal indicative of short-term environmental change. Using linear mixed-effects models, we identified best predictors of the variation in growth at two adjacent latitude subsets in the Commonwealth of the Northern Mariana Islands. We found different latitude subset growth responses for the years 2000–2013 and 2005–2017, indicating independent fluctuations in growth across latitude however, synchrony was present among individuals within a latitude range. Local environmental processes were more important than regional climatic processes for explaining N. unicornis growth in the north, but in the central islands, neither process had a clear effect. Otolith growth in fish inhabiting the north had a positive response to increased annual average sea surface temperature (SST). In adjacent central islands, otolith growth responded negatively to warmer winter SST. Baseline information for most fisheries on the direct impact of external forcings on fish, especially in tropical coral reef fisheries, remains sparse. We provide information on how climate and environment have impacted past growth with implications for future fisheries productivity monitoring.
... The pristine marine environment of many Pacific Island Countries and Territories (PICTs) is a major attraction for tourism (Asch et al. 2018) and access to remote places linked to aquatic environments is increasingly provided (Nicoll et al. 2016). The exceptional growth of the global marine tourism industry (Asch et al. 2018;Orams 2002) is reflected in steadily increasing tourism numbers in some PICTs, and very rapidly in other PICTs, over the last two decades ( Fig. 5.1). ...
... The pristine marine environment of many Pacific Island Countries and Territories (PICTs) is a major attraction for tourism (Asch et al. 2018) and access to remote places linked to aquatic environments is increasingly provided (Nicoll et al. 2016). The exceptional growth of the global marine tourism industry (Asch et al. 2018;Orams 2002) is reflected in steadily increasing tourism numbers in some PICTs, and very rapidly in other PICTs, over the last two decades ( Fig. 5.1). In line with those numbers, the type of dependence on marine areas, like reefs, is shifting from fishing to tourism in some countries and more specifically on some islands of these countries (Diedrich 2007;Hunter et al. 2018). ...
This book focuses on tropical coasts, which are highly vulnerable due to a multitude of stressors. Population growth is substantial, habitats are lost and biodiversity is reduced at an alarming rate, severely affecting many ecosystem services. This situation calls for sound coastal management and the effective engagement of all relevant stakeholders.
About two decades ago the M.Sc. program ISATEC (International Studies in Aquatic Tropical Ecology) was created at Bremen University (Germany) to train young scientists for a professional engagement in the complex field of tropical coastal and resource management. This book provides a platform for those Alumni to report on their work experiences and findings in their home countries and covers all regions of the tropical belt. Part I of the book provides a short review of the state of the tropical ocean and its resources and of international attempts towards sustainable ocean management starting with the Rio Declaration on Environment and Development in 1992. Part II deals with country case studies, and part III focuses on an evaluation & synopsis of those contributions. Emerging key issues for management and conservation of the tropical coastal environments are presented and critical challenges on the path towards reaching the Sustainable Development Goals (SDGs) are discussed, as are the needs for enhancing research and capacity development.
... The pristine marine environment of many Pacific Island Countries and Territories (PICTs) is a major attraction for tourism (Asch et al. 2018) and access to remote places linked to aquatic environments is increasingly provided (Nicoll et al. 2016). The exceptional growth of the global marine tourism industry (Asch et al. 2018;Orams 2002) is reflected in steadily increasing tourism numbers in some PICTs, and very rapidly in other PICTs, over the last two decades ( Fig. 5.1). ...
... The pristine marine environment of many Pacific Island Countries and Territories (PICTs) is a major attraction for tourism (Asch et al. 2018) and access to remote places linked to aquatic environments is increasingly provided (Nicoll et al. 2016). The exceptional growth of the global marine tourism industry (Asch et al. 2018;Orams 2002) is reflected in steadily increasing tourism numbers in some PICTs, and very rapidly in other PICTs, over the last two decades ( Fig. 5.1). In line with those numbers, the type of dependence on marine areas, like reefs, is shifting from fishing to tourism in some countries and more specifically on some islands of these countries (Diedrich 2007;Hunter et al. 2018). ...
Many Pacific Island Countries and Territories (PICTs) are characterised by unique marine ecosystems which attract millions of international visitors every year, creating a profitable business for tourist operators. On the downside, the rising tourist numbers are associated with changes in these ecosystems. We performed a literature search and reviewed 43 studies with a geographic scope covering the central Pacific, of which 16 focused on direct impacts of tourism on the marine environment. All but one study found negative or neutral effects of tourism on the marine environment. Only five studies present results from 2014 until present, which is insufficient, given the rapid increase in tourism numbers. Moreover, the majority of the studies focused on popular tourism destinations, indicating a spatial bias of the current knowledge about tourism impacts in the Pacific. In addition to the review, we highlight direct and indirect effects of tourism on marine ecosystems in the area by discussing two case studies. One case study relates to the feeding of reef fish in the Cook Islands by tourists, and the other to the introduction of invasive species in Galapagos. In both cases, species compositions at tourist sites differed from non-visited sites. Based on our review and discussion, we conclude that tourism can be responsible, and tourists may be willing to engage in conservation. We formulate four recommendations that suggest increased: (1) monitoring of the marine environment, (2) citizen science projects to include stakeholder observations for monitoring environmental change, (3) reciprocal knowledge exchanges among tourists, scientists and residents and (4) spatially balanced research on the effect of tourism on marine ecosystems with methods applicable to many PICTs.KeywordsIsland statesOcean environmentInvasive speciesFish feedingDisturbanceStakeholder knowledge exchange
... Sea level rise is also threatening human security and leading to outmigration from Pacific island and atoll countries [233,234]. Nations in Africa, Asia, Southeast Asia and the Pacific Islands that are near the Equator and with a high reliance on fisheries may be both more exposed and more susceptible to livelihood and food security impacts [203,225,235,236]. Many large coastal cities in low-and middle-income countries -such as Lagos (Nigeria), Manila (Philippines), and Bangkok (Thailand) -are situated in floodplains and may have lower institutional capacity to be able to adapt [237][238][239][240]. Coastal populations in Equatorial and Arctic regions may experience some of the most extreme changes in temperature and species composition [235,236,241,242]. ...
... Nations in Africa, Asia, Southeast Asia and the Pacific Islands that are near the Equator and with a high reliance on fisheries may be both more exposed and more susceptible to livelihood and food security impacts [203,225,235,236]. Many large coastal cities in low-and middle-income countries -such as Lagos (Nigeria), Manila (Philippines), and Bangkok (Thailand) -are situated in floodplains and may have lower institutional capacity to be able to adapt [237][238][239][240]. Coastal populations in Equatorial and Arctic regions may experience some of the most extreme changes in temperature and species composition [235,236,241,242]. Notably, the impacts of climate change tend to be experienced to a greater extent in lower income countries, and by those less responsible for producing carbon and causing climate change [29,171]. ...
Environmental justice refers broadly to the distribution of environmental benefits and burdens, and the fair treatment and meaningful involvement of all people in environmental decision-making and legal frameworks. The field of environmental justice initially developed out of a concern for the disproportionate distribution and impacts of environmental pollution and hazardous waste disposal on groups that have been historically and structurally marginalized, including Black populations and socio-economically disadvantaged communities. More recent environmental justice scholarship has expanded geographically and focused on a broader set of environmental hazards and harms, such as climate change impacts, biodiversity and habitat loss, and ecosystem service declines. Yet, the impacts and distribution of environmental hazards and harms in the marine environment on coastal populations has received less attention in the environmental justice literature. This narrative review paper starts to address this gap through a focus on five main areas of environmental injustice in the ocean: 1) pollution and toxic wastes, 2) plastics and marine debris, 3) climate change, 4) ecosystem, biodiversity and ecosystem service degradation, and 5) fisheries declines. For each, we characterize the issue and root drivers, then examine social and distributional impacts. In the discussion, we explore how these environmental injustices are converging and interacting, cumulative, differentiated, and geographically distributed, and briefly examine solutions and future research directions. In conclusion, we call for greater and more explicit attention to environmental justice in ocean research and policy.
... The global climate is constantly changing as the concentration of greenhouse gases increases. They mostly affect marine ecosystems as a result of acidification, warming, and natural disasters (floods, tsunamis, and so on) [4][5][6][7][8][9][10][11][12]. The release of extreme greenhouse gases has serious irreversible consequences in the form of climate change and rising temperatures. ...
... The authors of that research established mathematically and empirically that the consequences of global warming continue to harm entire ecosystems, and that if this scenario continues, 80-90 percent of the diversity of ecological systems could be lost by the end of this century. The effects of climate change on the coastal habitats of the Pacific Ocean were scientifically examined by Asch et al. [10]. The most current analysis distinguishes each of these contributions as a component of the marine ecosystem, and Table 1 makes this distinction quite evident. ...
It is generally observed that aquatic organisms have symmetric abilities to produce oxygen (O2) and fix carbon dioxide (CO2). A simulation model with time-dependent parameters was recently proposed to better understand the symmetric effects of accelerated climate change on coastal ecosystems. Changes in environmental elements and marine life are two examples of variables that are expected to change over time symmetrically. The sustainability of each equilibrium point is examined in addition to proving the existence and accuracy of the proposed model. To support the conclusions of this research compared to other studies, numerical simulations of the proposed model and a case study are investigated. This paper proposes an integrated bibliographical analysis of artificial neural networks (ANNs) using the Reverse-Propagation with Levenberg–Marquaradt Scheme (RP-LMS) to evaluate the main properties and applications of ANNs. The results obtained by RP-LMS show how to prevent global warming by improving the management of marine fish resources. The reference dataset for greenhouse gas emissions, environmental temperature, aquatic population, and fisheries population (GAPF) is obtained by varying parameters in the numerical Adam approach for different scenarios. The accuracy of the proposed RP-LMS neural network is demonstrated using mean square error (MSE), regression plots, and best-fit output. According to RP-LMS, the current scenario of rapid global warming will continue unabated over the next 50 years, damaging marine ecosystems, particularly fish stocks.
... Sea level rise is also threatening human security and leading to outmigration from Pacific island and atoll countries (Barnett & Adger, 2003;Campbell & Warrick, 2014). Nations in Africa, Asia, Southeast Asia and the Pacific Islands that are near the Equator and with a high reliance on fisheries may be both more exposed and more susceptible to livelihood and food security impacts (Asch et al., 2017;Holbrook et al., 2021;Lauria et al., 2018;Tigchelaar et al., 2021). Many large coastal cities in low-and middle-income countries -such as Lagos (Nigeria), Manila (Philippines), and Bangkok (Thailand) -are situated in floodplains and may have lower institutional capacity to be able to adapt (Araos et al., 2016;Elias & Omojola, 2015;Porio, 2014;Saito, 2014). ...
... Many large coastal cities in low-and middle-income countries -such as Lagos (Nigeria), Manila (Philippines), and Bangkok (Thailand) -are situated in floodplains and may have lower institutional capacity to be able to adapt (Araos et al., 2016;Elias & Omojola, 2015;Porio, 2014;Saito, 2014). Coastal populations in Equatorial and Arctic regions may experience some of the most extreme changes in temperature and species composition (Asch et al., 2017;Ford et al., 2019;Holbrook et al., 2021;. Notably, the impacts of climate change tend to be experienced to a greater extent in lower income countries, and by those less responsible for producing carbon and causing climate change (Bindoff et al., 2019;Lamb et al., 2021). ...
Environmental justice refers broadly to the distribution of environmental benefits andburdens, and the fair treatment and meaningful involvement of all people in environmental decision-making and legal frameworks. The field of environmental justice initially developed out of a concern forthe disproportionate distribution and impacts of environmental pollution and hazardous waste disposalon groups that have been historically and structurally marginalized, including Black populations andsocio-economically disadvantaged communities. More recent environmental justice scholarship hasexpanded geographically and focused on a broader set of environmental hazards and harms, such asclimate change impacts, biodiversity and habitat loss, and ecosystem service declines. Yet, the impactsand distribution of environmental hazards and harms in the marine environment on coastalpopulations has received less attention in the environmental justice literature. This narrative reviewpaper starts to address this gap through a focus on five key environmental hazards and harms that areoccurring in the marine and coastal environment: 1) pollution and toxic wastes, 2) plastics and marinedebris, 3) climate change, 4) ecosystem, biodiversity and ecosystem service degradation, and 5)fisheries declines. For each, we characterize the issue and root drivers, then examine social anddistributional impacts. In the discussion, we explore how impacts are differentiated, inequitably distributed, converging and cumulative and briefly examine solutions and future research directions. In conclusion, we call for greater and more explicit attention to environmental justice in ocean research and policy.
... Bahamians have a birthright to their waters and associated resources, but the ability of its waters to support its residents is wavering like other island nations (e.g., Newton et al. 2007;Asch, Cheung, and Reygondeau 2018;Lam et al. 2020). For example, conch is harvested and prepared by Bahamians to embrace cultural traditions, and tourists who visit The Bahamas often seek these dishes (Moultrie et al. 2016;Bomhauer-Beins, de Guttry, and Ratter 2019). ...
Fisheries are essential for nutritional and economic stability in many countries, particularly small island developing states. In The Bahamas, ~25% of households depend on fisheries‐related income, and Bahamians rely on seafood for ~15% of their animal protein. However, our understanding of fisheries is largely based on national statistics that may not reflect the diversity of fishers, particularly in less developed Family Islands. We interviewed 375 Bahamian fishers from five major islands, Abaco, Andros, Eleuthera, Long Island, and New Providence, that varied in socioeconomics, human population density, natural resource diversity, and cultural practices. Bahamian fishers were largely driven by economics, with ~70% identifying as commercial fishers and > 80% of income derived from fishing activities for all fishers. Fishers in more developed islands used more modern methods (e.g., diving, pots & traps) to catch economically valuable species (e.g., Panulirus argus ) at greater distances from home islands, aided by larger fishing vessels. In contrast, fishers from Family Islands used more traditional methods (e.g., handlines) to catch Lutjanidae and other species in nearshore waters closer to home islands. Variability among islands appears to be attributed to differences in access to resources, infrastructure, financial motivation, and cultural practices. Similar to other small developing island nations, diversity in fisher behavior among and within Bahamian islands necessitates more attention and resources to develop, implement, and enforce fisheries regulations to ensure sustainability, which is essential as global demand for seafood continues to grow amidst widespread overfishing.
... Not only do tropical marine fisheries provide important socioeconomic benefits to local communities, but they also account for approximately half of the annual global fish production (Lam et al. 2020). However, the maximum catch yield of marine fish stocks from equatorial waters is projected to decrease by up to 40% under future climate scenarios, threatening economic security, social dynamics, and human health (Asch et al. 2018;Lam et al. 2016). Despite substantial advances in understanding how climate change affects fish ecology over the past decade, there is still a significant knowledge gap regarding the impact of widespread environmental change on equatorial fish populations (Bass et al. 2021;Nagelkerken et al. 2023;Wilson et al. 2010). ...
Climate change potentially poses a major threat to tropical marine fish populations, many of which are nearing their thermal tolerance limits. Despite their importance to global food security, our understanding of how changing ocean conditions will affect these fish populations, particularly from the equator, remains limited. Annual growth increments accreted in fish otoliths, when correlated to environmental parameters, provide valuable insights into how species might respond to climate variation. This study aimed to assess the relative importance of demographic and environmental drivers on the annual otolith growth expression of two tropical snappers, Lutjanus johnii and L. malabaricus, from the Indo-West Pacific region. We analysed 5594 growth increments from the otoliths of 1042 fish, reconstructing growth chronologies over four decades, spanning more than 25 degrees of latitude across the equator. For L. johnii from Southeast Asia, growth was explained by mean sea surface temperatures over the past two years, consistent with the Temperature-Size Rule. Growth of L. johnii from northwestern (NW) Australia was linked to the intensity of the Indian Ocean Dipole during the austral summer and autumn, likely associated with changes in ecosystem productivity. For juvenile L. johnii from NW Australia, growth was negatively impacted by rainfall in February and March. In comparison, L. malabaricus showed a more pronounced influence of demographic variables across regions and life stages, with only weak effects from environmental drivers. These findings highlight the complex growth responses of these species to demographic and environmental factors from an important yet understudied region of the world.
... Projected oceanographic changes from model simulations are expected to significantly affect various aspects of marine fisheries, including species abundance, potential catch, fisheries productivity, revenue, and livelihoods (Das et al., 2020;Lam et al., 2016aLam et al., , 2016b. The Intergovernmental Panel on Climate Change (IPCC) considers two climate change scenarios, RCP 2.6 and RCP 8.5, as common frameworks for predicting the lowest and highest increases in global temperatures resulting from GHG concentrations (Asch et al., 2018;Fernandes et al., 2020a;Nataniel et al., 2022). Various index models have also been developed to analyze the predicted impacts of climate change on fisheries production (Blasiak et al., 2017). ...
Climate change presents profound challenges to marine ecosystems and fisheries, necessitating effective management and adaptive strategies. Simultaneously, marine fisheries exacerbate climate change by emitting greenhouse gases through fuel combustion and electricity consumption. This article reviews 142 studies on the bidirectional interactions between climate change and marine fisheries (ICCMF), utilizing bibliometric methods including co-occurrence network analysis, cluster analysis, and conceptual framework analysis to identify research trends, challenges, and gaps. The bibliometric analysis reveals an explosive growth in publications and patents related to ICCMF since 2020. The key themes in ICCMF research encompass: (a) the impacts of climate change on marine fisheries, (b) the contribution of marine fisheries to climate change, (c) stakeholder perceptions and responses to climate change, and (d) adaptive management strategies for climate-resilient fisheries. Notably, recent studies have increasingly focused on carbon emissions and carbon sinks in marine fishery industries, emphasizing the need for further research into carbon reduction practices to mitigate climate change. This review identifies several challenges, including geographical disparities, knowledge inequality, "parachute science" and "helicopter research," issues with data quality and management, and inadequate capacity to adapt to climate change. Key research gaps include the limited representation of perspectives from the Global South, the absence of sustained partnerships, imbalances in research collaboration, restricted data accessibility and reliability, and an inadequate understanding of fisheries' carbon emissions. This review provides valuable insights for researchers, policymakers, and stakeholders, highlighting the need for strategic management approaches to mitigate adverse impacts and promote marine ecosystem sustainability.
... Consequently, food provision from oceans in many regions is already affected and predicted to become more so in the future (Hoegh-Guldberg et al. 2019). For example, it is likely that more than 50% of exploited fishes and invertebrates from the exclusive economic zones of the Pacific Island states will become locally extinct by 2100 (Asch et al. 2018 ). ...
Islands play a central role in understanding the ecological and evolutionary processes that shape life but are rarely used to untangle the processes that shape human, animal, and environmental health. Islands, with their discrete human and animal populations, and often well-studied ecological networks, serve as ideal natural laboratories for exploring the complex relationships that shape health across biomes. Relatively long coastlines and, in some cases, low lying topography also make islands sentinels for climate change. In this article, we examine the potential of islands as valuable laboratories and research locations for understanding the One Health nexus. By delving into the challenges faced in island settings, we provide valuable insights for researchers and policymakers aiming to globally promote and apply One Health principles. Ultimately, recognizing the interconnected health of humans, animals, and the environment on islands contributes to efforts aimed at promoting global health and sustainability.
... However, some elements limit the use of these values in real life (Dahlke et al., 2020;Pörtner & Peck, 2010) We, therefore, preferred to use thermal data associated with the spatial distribution of each species from the Aqua X project (Asch et al., 2018;Reygondeau, 2019). This provides us with thermal data closer to reality, estimated homogeneously for a large set of species, including both mobile and sessile fish, crabs, cephalopods and bivalves. ...
Ocean warming is driving significant changes in the structure and functioning of marine ecosystems, shifting species' biogeography and phenology, changing body size and biomass and altering the trophodynamics of the system. Particularly, extreme temperature events such as marine heatwaves (MHWs) have been increasing in intensity, duration and frequency. MHWs are causing large‐scale impacts on marine ecosystems, such as coral bleaching, mass mortality of seagrass meadows and declines in fish stocks and other marine organisms in recent decades. In this study, we developed and applied a dynamic version of the EcoTroph trophodynamic modelling approach to study the cascading effects of individual MHW on marine ecosystem functioning. We simulated theoretical user‐controlled ecosystems and explored the consequences of various assumptions of marine species mortality along the food web, associated with different MHW intensities. We show that an MHW can lead to a significant biomass reduction of all consumers, with the severity of the declines being dependent on species trophic levels (TLs) and biomes, in addition to the characteristics of MHWs. Biomass of higher TLs declines more than lower TLs under an MHW, leading to changes in ecosystem structure. While tropical ecosystems are projected to be sensitive to low‐intensity MHWs, polar and temperate ecosystems are expected to be impacted by more intense MHWs. The estimated time to recover from MHW impacts is twice as long for polar ecosystems and one‐third longer for temperate biomes compared with tropical biomes. This study highlights the importance of considering extreme weather events in assessing the effects of climate change on the structures and functions of marine ecosystems.
... Ocean acidification threatens coral reefs and marine ecosystems, and fisheries are projected to suffer catch declines of over 50 percent by 2100 if greenhouse gas emissions are not curbed. 18 Where food transport costs are already high, as in the Pacific Islands, climate change can exacerbate existing food shortages 19 ; food insecurity also results in malnutrition and unbalanced diets. Vector-borne diseases, such as dengue fever, are another indirect consideration associated with climate change, especially drought and increased temperatures. ...
Climate change impacts-temperature and rainfall changes, extreme events, sea level rise, and ocean acidification-are amplifying health risks in vulnerable populations throughout the Pacific Islands, and also influence their mobility. This nexus of climate change, health, and migration is evident in the experience of the Marshall Islands. The nation and its population are dispersed over almost two million square kilometers of ocean, with sizeable diasporas in the United States. Climate impacts in the Marshall Islands exacerbate ongoing health threats, such as limited drinking water supplies, inadequate nutrition, and poor infrastructure. The out-migration of Marshallese is largely motivated by health, economic, education, and environmental reasons; therefore, planning for migrant movements should include adaptation strategies that also reduce health risks. A better understanding of how health, mobility, and climate change interact will help shape policy responses and provide useable climate information for focused, timely interventions that maximize health and well-being among populations in motion. Laura Brewington is a research fellow at the East-West Center, the lead investigator of the Pacific Islands Climate, Health, and Migration project, and the co-lead investigator of the Pacific Regional Integrated Sciences and Assessments (RISA) program. She designs and conducts collaborative, policy-oriented research to support climate adaptation in Pacific Islands. Kelli Kokame is a second-year medical student at the John A. Burns School of Medicine, University of Hawaiʻi at Mānoa. Prior to beginning medical school, she was an intern and a project specialist for the East-West Center Pacific RISA program on climate, health, and migration, and the Pacific Islands Regional Climate Assessment, with a focus on the Marshall Islands. Nancy Lewis is an adjunct senior fellow at the East-West Center and the former director of the research program. Her research has revolved around the intersection between health and the environment, and she has over 30 years of field experience in the Pacific Islands. Papers in the AsiaPacific Issues series feature topics of broad interest and significant impact relevant to current and emerging policy debates. The views expressed are those of the author and not necessarily those of the Center.
... Over the last century, human activities-overfishing foremost among them-have increasingly impacted marine life, precipitating acute declines in biomass and diversity (Cardinale et al., 2012;Di Minin et al., 2019;Díaz et al., 2019;Jackson et al., 2001). In addition to continued pressure from overfishing and habitat loss, the marine environment is experiencing the ongoing effects of anthropogenic climate change (Simpson et al., 2011), from which marine ecosystems and the services they provide are increasingly under threat (Asch et al., 2018;Rocha et al., 2015). ...
Aim
Human pressure in the oceans is pervasive and affects marine life. Understanding species' differing responses to human pressure, and how human pressure compares to other environmental variables in shaping marine communities is needed to facilitate the sustainable management of the seas. Despite theory and empirical evidence that fishing pressure affects marine life‐history strategies, several recent large‐scale studies have not shown strong relationships between fishing pressure and community composition. We aim to reconcile theory with data and explain these variable findings, testing the hypothesis that the signal of the effect of fishing pressure on marine communities depends on the scale at which the community is defined.
Location
North East Atlantic.
Time Period
2009 to 2021.
Major Taxa Studied
Marine vertebrates (Teleostei, Elasmobranchii, Petromyzonti, Holocephali).
Methods
We collate extensive scientific marine biodiversity surveys, published life‐history traits and high‐resolution annual fishing pressure data. Using frequentist Generalized Linear Mixed Models, we assess whether community mean weighted life‐history traits correlate with fishing pressure, sea surface temperature and depth and whether the strength of these relationships are scale dependant.
Results
We show fish community life‐history strategy correlates with fishing pressure, and the relative importance of fishing pressure compared to environmental variables increases with the scale at which a community is defined.
Main Conclusions
We suggest this scale dependence relates to the spatial extent over which covariates vary, and how fish movement moderates communities' experience of this variability. Our findings highlight the importance of explicit consideration of scale in ecological research, supporting the idea that studying systems at ecologically relevant scales is necessary to detect and appropriately interpret the effects of global change.
... The impacts of climate change food and nutrition security are also probable to initiate undernourishment and worsen the problem of diet-related NCDs. Climate change is predicted to adversely affect fisheries and agriculture productivity; impair livelihoods and enhance migration; food system instability, the provision of lower-quality humanitarian food support, and volatile and increasing prices of food amongst others (Asch et al. 2018). Change in climate is probably going to have a promising effect on the wheat crop weeds that play a very dynamic role in worldwide food security (Bajwa et al. 2020). ...
Climate change is a leading element for variation in crop responses and correlates mainly with other stresses (abiotic and biotic stresses), which are accountable for poor crop productivity. Many climatic factors affect crop productivity and overall agricultural land in a number of various ways, for instance, rainfall variations, temperature fluctuations, genetic modification of weeds, pests, and an increase in CO2 concentration. Variation in global climate has fascinated various investigators and scientists with regard to ensuring global food security. According to many published reports, agriculture has become the most vulnerable field negatively affected by climatic variation. Crops responses have become entirely changed in climatic fluctuations, which ultimately lead to poor crop yield. The only single solution to overcoming all the climatic variations and to improving crop productivity is to go for climate-resilient agriculture. The adaptation of climate-resilient agriculture and climate-resilient crop genotypes may lead to global food security. In this chapter, climate change and its impact on crop production, and the possible agronomic, breeding, and genomic strategies for overcoming the negative impacts of climate change in crop production are discussed. This will enhance the knowledge of the reader with regard to food production strategies under the climate change scenario.
... Research suggests that ocean warming may increase the suitability of some habitats for skipjack tuna (Muhling et al. 2015), while for yellowfin tuna temperature above a threshold may have adverse effects on cardiac functionality of spawning adults and survival of eggs and larvae (Wexler, Margulies, and Scholey 2011;Dell'Apa et al. 2018). A large literature on tuna in the Pacific Ocean exists, focusing primarily on the physical effects of SST on spawning and redistribution (see, e.g., Erauskin-Extramiana et al. 2019;Muhling et al. 2017;Pecoraro et al. 2017;Monllor-Hurtado, Pennino, and Sanchez-Lizaso 2017;Lehodey et al. 2013;Schaefer, Fuller, and Block 2007) and the geopolitical implications of shifting tuna stocks (see, e.g., Bell et al. 2018;Asch, Cheung, and Reygondeau 2018). ...
... These changes can decrease the benefits and ecological services of coastal marine, and freshwater ecosystems [4]. Meanwhile, it is reported [5], [6], and [7] that coastal and marine ecological damage due to climate change causes a decrease in fishery production and loss opeople's livelihoods. ...
Mangroves can store carbon. However, it also produces carbon emissions by degrading organic matter in mangrove sediments. This research was conducted in a mangrove ecosystem at Waiheru, in the inner Ambon bay, to determine CO 2 and CH 4 emissions and their potential for global warming (GWP) from mangrove sediments. Gas is taken through a syringe mounted on the hood. Gas concentration analysis used the gas chromatography method, while the average gas concentration in each sediment was tested using ANOVA Single Factor. The results showed that the average concentration of CO 2 gas was significantly different for each sediment (P-value <0.05), while the average concentration of CH 4 gas was not significantly different (P-value >0.05). The largest CO 2 gas emission in mangrove sediments in Waiheru Village was found in sandy mud sediments with an emission value of 136.99 mg.m ⁻² .h ⁻¹ , and the lowest was in sand sediments, namely 13.01 mg.m ⁻² .h ⁻¹ . Meanwhile, the largest emission of CH 4 gas was in silty sand sediments, namely 0.32 mg.m ⁻² .h ⁻¹ , and the lowest was in sandy mud sediments, namely 0.15 mg.m ⁻² .h ⁻¹ . Fluctuations in carbon gas emissions in each sediment are inversely proportional, which indicates that the formation of CH 4 gas is obtained through ethanol reduction, which utilizes CO 2 gas concentrations. The total GWP in the mangrove sediments of Waiheru Village is 231.58 mg.m ⁻² .h ⁻¹ . The GWP contributed by the type of sandy silt sediment was 140.72 CO 2 -eq mg.m ⁻² .h ⁻¹ , muddy sand was 70.95 mg.m ⁻² .h ⁻¹ , and sand sediment was 19.91 CO 2 -eq mg.m ⁻² . h ⁻¹ .
... However, albacore and skipjack were still caught in Tonga in the salinity range of 35 PSU-37 PSU (Figure 3) even when the previous finding stated that their salinity preference is much more well defined [66][67][68]. Our results showed that SST has the highest contribution in predicting suitability habitats followed by SSS for all species (Figure 3). ...
The potential impacts of climate change on the distribution of tuna in Pacific Island countries’ exclusive economic zones have yet to be investigated rigorously and so their persistence and abundance in these areas remain uncertain. Here, we estimate optimal fisheries areas for four tuna species: albacore (Thunnus alalunga), bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin (Thunnus albacares). We consider different climate change scenarios, RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5, within a set of tuna catch records in the exclusive economic zone of Tonga. Using environmental and CPUE datasets, species distribution modelling estimated and predicted these fisheries areas in the current and future climatic scenarios. Our projections indicate an expansion in area and a shift of productive areas to the southern part of this exclusive economic zone of Tonga. This is an indication that future climatic scenarios might be suitable for the species under study; however, changes in trophic layers, ocean currents, and ocean chemistry might alter this finding. The information provided here will be relevant in planning future national actions towards the proper management of these species.
... Given that Rapa Nui is an isolated territory in the southeastern Pacific Ocean, far from South America, it is relevant to have information to develop specific adaptation strategies and reduce climate change impacts on the island. Coastal areas must adapt to boost their resilience to increasingly intense climate changes [8,[23][24][25][26]. ...
We studied atmospheric corrosion on Rapa Nui Island, using galvanized and non-galvanized SAE 1020 steel samples exposed on racks. We also added Charpy samples of both materials to directly determine the effect of corrosion rate on these materials' impact toughness. The results indicated a correlation between corrosion rate and toughness loss in the studied materials. In the corrosion study, we could also demonstrate the effect from increased insular population growth on contaminants which aid atmospheric corrosivity. Results showed that atmospheric SO2 has tripled compared with similar corrosion studies done 20 years ago (Mapa Iberoamericano de Corrosión, MICAT), increasing corrosion rates. Our results show how human factors can influence changes in environmental variables that strengthen corrosion.
... Beberapa penelitian menyebutkan bahwa perubahan yang muncul sebagai dampak dari climate change, misalnya kenaikan suhu perairan, meningkatnya pengendapan, pH, salinitas, oksigen, kecepatan angin, gelombang, dan kenaikan muka laut yang secara signifikan berpengaruh terhadap kondisi ekologi atau penurunan jasa layanan ekosistem di laut maupun di perairan tawar (Brander 2010;Cheung et al. 2009;Drinkwater et al. 2009;Jones 2013;Wang et al. 2016). Lebih lanjut, perubahan iklim juga dapat berdampak pada penurunan produksi perikanan dan mata pencaharian masyarakat (Asch et al. 2017;Belhabib et al. 2016;Coulthard 2008;Ohwayo et al. 2016;Rosegrant et al. 2016;Shaffril et al. 2017ab;Valmonte-Santos et al. 2016), serta dapat memengaruhi keamanan pangan (food security) (Ding et al. 2017). ...
Buku ini memuat tentang berbagai metode dan analisis data terkait studi ekosistem mangrove. Cocok menjadi buku pedoman bagi para peneliti dan pemerhati ekosistem mangrove.
... The lack of studies in the area on tuna species distribution, environmental preferences and climate change impacts on tuna limits our discussion to comparable and corresponding studies. Although tuna is well known as a migratory species, little is known about its local distribution such as the EEZ of small Pacific Island Countries like Tonga [60,61]. Distribution modeling studies are thus essential for optimizing the necessary information on potential productive sites and their environmental traits to enable prediction of suitable areas for the current and future occurrence of these species. ...
The potential impacts of climate change on the distribution of tuna in Pacific Island Countries’ Exclusive Economic Zones have yet to be investigated rigorously, and so their persistence and abundance in these areas remain uncertain. Here, we estimate optimal fisheries areas for four tuna species; Albacore (Thunnus alalunga), Bigeye (Thunnus obesus), Skipjack (Katsuwonus pelamis), and Yellowfin (Thunnus albacares). We consider different climate change scenarios, RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, within a set of tuna catch records in the Exclusive Economic Zone of Tonga. Using environmental and CPUE datasets, species distribution modelling estimated and predicted these fisheries areas in the current and future climatic scenarios. Our projections indicate an expansion in area and a shift of productive areas to the southern part of this Exclusive Economic Zone of Tonga. This is an indication that future climatic scenarios might be suitable for the species under study however, changes in trophic layers, ocean currents and ocean chemistry might alter this finding. Information provided here will be relevant in planning future national actions towards proper management of these species.
... At a global scale, the biodiversity distribution estimated from our study appears to be relatively consistent with other studies, resolutions and analyses (Fig. 10.1;Tittensor et al. 2010;Asch et al. 2018;Reygondeau 2019). The pattern across multiple taxa is primarily tropical to subtropical peaks ...
Marine habitats are extremely valuable in many ways (e.g., economically, culturally or for subsistence) and provide many necessary services for humans (Costanza et al. 1997, 2014). Despite their importance, coastal and oceanic habitats are increasingly threatened by fishing, climate change, oil and gas exploration, pollution and coastal development (Jackson et al. 2001; Halpern et al. 2008, 2019; Heery et al. 2017; Harris 2020). Habitat degradation and loss from these threats are not uniformly distributed and are cumulative with poorly understood interactions between pressures (Halpern et al. 2008). Despite the enormous impacts humans have had on marine ecosystems in the global ocean over the past 50 years, they tend to appear not as the complete extinction of individual species (Dulvy et al. 2003) but rather as changes in ecosystem composition and in the relative abundance and ecological status of individual species, along with more regional or local extirpations (Worm and Tittensor 2011). A species need not become globally extinct to radically alter the composition of the ecosystem (‘ecological extinction’), disappear from the local environment (‘local extinction’) or become commercially non-viable (‘commercial extinction’). Biodiversity loss is a globally significant symptom of unsustainable exploitation of Earth’s natural environment and a major threat to the ecosystem services on which we, and future generations, depend.
... It is crucial to account for such sampling bias when examining the distribution of biodiversity (Gagn e et al., 2020;Hughes et al., 2021;Tittensor et al., 2010). At a global scale analyses of marine biodiversity data indicate a peak at tropical to sub-tropical latitudes with particular hotspots focused around the Indo-Pacific Coral Triangle and to a lesser extent the Caribbean (Asch et al., 2018;Reygondeau, 2019;Rogers et al., 2020;Tittensor et al., 2010;Figs 1 and 2). The central and western Indian Ocean, Red Sea, South West Pacific Islands (i.e., the Bismarck Archipelago, the Great Sea Reef of Fiji, New Caledonia, New Guinea, the Solomon Islands, Vanuatu) and Southeast Asia also show the highest levels of species richness (Rogers et al., 2020;Figs 1 and 2). ...
We review the current knowledge of the biodiversity of the ocean as well as the levels of decline and threat for species and habitats. The lack of understanding of the distribution of life in the ocean is identified as a significant barrier to restoring its biodiversity and health. We explore why the science of taxonomy has failed to deliver knowledge of what species are present in the ocean, how they are distributed and how they are responding to global and regional to local anthropogenic pressures. This failure prevents nations from meeting their international commitments to conserve marine biodiversity with the results that investment in taxonomy has declined in many countries. We explore a range of new technologies and approaches for discovery of marine species and their detection and monitoring. These include: imaging methods, molecular approaches, active and passive acoustics, the use of interconnected databases and citizen science. Whilst no one method is suitable for discovering or detecting all groups of organisms many are complementary and have been combined to give a more complete picture of biodiversity in marine ecosystems. We conclude that integrated approaches represent the best way forwards for accelerating species discovery, description and biodiversity assessment. Examples of integrated taxonomic approaches are identified from terrestrial ecosystems. Such integrated taxonomic approaches require the adoption of cybertaxonomy approaches and will be boosted by new autonomous sampling platforms and development of machine-speed exchange of digital information between databases.
... These oceanographic variables were selected because changes in these variables are likely to have large impacts Note either the very short proboscis or absence of a proboscis, which is a typical age dimorphic trait found in subadult and juvenile males, respectively. on marine species through either direct effects on physiology or alterations of the trophodynamics of marine ecosystems (Asch et al., 2018;Reygondeau, 2019). For the specific case of the SES, the selection of these oceanographic variables is considered important as they readily influence the foraging ecology, ecological niche, and distribution of this species in the ocean (Bailleul et al., 2007;Biuw et al., 2010;Hofmeyr, 2015;Albouy et al., 2020). ...
The southern elephant seal (Mirounga leonina) is a species distributed in the circumpolar region and Southern Ocean; however, a significant number of new off-range sightings have been reported over the years. Using historical and recent sightings from 1989 to 2022 of M. leonina along the Eastern Tropical Pacific (ETP), including the newest records in Galapagos Islands and other areas, we assessed the species occurrence in this region. Overall opportunistic observations of M. leonina were recorded, i.e., Peru (n=14), Ecuador (n= 15), Colombia (n= 4), Panamá (n= 1), Guatemala (n = 1), Salvador (n= 1), and Mexico (n= 3) between 1989 and mid-2022. To understand the presence and frequency of this species in the ETP as a potential new habitat, a habitat suitability index (HSI) was developed to correlate extralimital distribution in relation to environmental variables and sea surface temperature anomalies (Southern Oscillation Index: >-3°C to -0.5°C) associated to atmospheric-oceanographic episodes such as La Niña events. Plausible habitat suitability for this species is expected to increase (HSI anomaly= 5 to >15%) along the ETP in response to ocean environmental changes. With an increasing occurrence of M. leonina in recent years, we postulate the influence of oceanographic-climatic conditions exacerbated by climate change for the increased off-range sightings in these regions.
... Substantial differences in SDM projections be tween climate scenarios are common when projecting the response of marine ectotherms to climate change (e.g. Asch et al. 2018), likely due to the strong dependence of these organisms on temperature (Pörtner 2002). Given that considerable uncertainty exists regarding the extent of future warming under climate change (IPCC 2021), it is unclear which RCP scenario future climate will track most closely. ...
Climate change is expected to create more favourable climatic conditions for many invasive species, increasing their abundance and range. One such invasive species is Membranipora membranacea , an epiphytic bryozoan causing defoliation of kelp beds in the northwest Atlantic Ocean (NWA). The impact of M. membranacea is directly linked to its abundance, which is anticipated to increase due to climate change. Additionally, further range expansion may threaten Arctic kelp beds in the future. We constructed a species distribution model (SDM) to predict the abundance of M. membranacea in the NWA under present and future climate scenarios. We also assessed the effect of a possible additional invasion of M. membranacea from populations in Norway. The projected future abundance distribution of M. membranacea in the NWA differed substantially depending on the future climate scenario employed, but the bryozoan was predicted to occur in the Arctic at low abundances regardless of the scenario. However, we also found that populations of M. membranacea in Norway achieve much higher abundances at lower temperatures than NWA populations and could pose a dire threat to kelp beds in the NWA and southern Canadian Arctic if introduced in these regions. Although the SDMs performed well under internal validation, estimating the impact of M. membranacea is complicated by the context-dependent response of kelp communities to coverage by the bryozoan. Nonetheless, this study provides valuable predictions of the response of an ecologically significant invasive species to climate change with findings of broader relevance to the study of other invasive organisms.
... Marine ecosystems are particularly vulnerable, as climate change is not causing ocean warming alone, but also associated increases in precipitation, causing seawater freshening [4], stratification, leading to declining seawater oxygen levels [5], and ocean acidification as the oceans continue to absorb atmospheric CO 2 [6][7][8]. Tropical regions of the world's oceans are projected to be some of the most impacted by these effects [9][10][11][12]. At the same time, these 'direct' climate change effects can also instigate structural changes to the microbial community at the base of the marine food chain ('indirect effects') in terms of both species' abundance and composition, including in tropical regions [13][14][15][16]. ...
... Marine ecosystems are particularly vulnerable, as climate change is not causing ocean warming alone, but also associated increases in precipitation, causing seawater freshening [4], stratification, leading to declining seawater oxygen levels [5], and ocean acidification as the oceans continue to absorb atmospheric CO 2 [6][7][8]. Tropical regions of the world's oceans are projected to be some of the most impacted by these effects [9][10][11][12]. At the same time, these 'direct' climate change effects can also instigate structural changes to the microbial community at the base of the marine food chain ('indirect effects') in terms of both species' abundance and composition, including in tropical regions [13][14][15][16]. ...
Research characterising the effects of future climate change on the marine environment remains heavily focussed on that of temperate regions and organisms. Furthermore, little is known of these effects on the early life stages of many marine species. Tropical regions are already experiencing an increase in sea surface temperature and decrease in sea surface salinity, conditions favoured by pathogenic bacteria such as Vibrio spp. The early life stages of crabs are known to be particularly vulnerable to both the direct physiological effects of climate change and exposure to harmful microorganisms, yet there are limited data on these effects on juveniles of many tropical crustacean species. This study assessed the metabolic responses of mud crab (Scylla serrata) juveniles to warming and/or freshening in the presence or absence of pathogenic bacteria in southwest India. Juvenile crabs were exposed to either ambient (28 °C/30 PSU) or one of three projected climate change regimes (28 °C/20 PSU (freshening), 32 °C/30 PSU (warming), 32 °C/20 PSU (warming + freshening)) for 10 days, in either the presence or absence of the pathogenic bacteria Vibrio parahaemolyticus. Results show that simulated climate change conditions, especially freshening, caused a significant increase in oxygen consumption rates (MO2), and that these were further increased when juveniles were exposed to V. parahaemolyticus. These results suggest that the effects of future climate change conditions could have significant implications for the conservation of wild stocks and commercial farming of this species in South Asia.
... However, there has been less research on the characteristics of the subsurface marine environment under abnormal climate conditions and the impact on fishery resources. Climate change threatens tropical marine fisheries [7]. The large-scale effects of abnormal climate events on the marine environment have a significant impact on fishery resources and fishing ground distribution. ...
To explore the impact of climate change on fishery resources, the temporal and spatial characteristics of the thermocline in the main yellowfin tuna purse-seine fishing grounds in the western and central Pacific Ocean during La Niña and El Niño years were studied using the 2008–2017 Argo grid data (BOA_Argo) and the log data of commercial fishing vessels. A generalized additive model (GAM) was used to analyze the variables affecting yellowfin tuna fishing grounds. The results showed that in La Niña years, the catch per unit effort (CPUE) moved westward as the high-value zone of the upper boundary contracted westward to 145° E, and in the El Niño years this moved eastward to 165° E. Compared with normal years, the upper boundary depth difference of the thermocline on the east and west sides of the equatorial Pacific was larger in La Niña years, and the upper boundary depth of 80–130 m shifted westward. The thermocline strength was generally weaker in the west and stronger in the east. The thermocline had two band-like distribution structures with an axis at 15° N and 15° S. The CPUE was distributed from 120 m to 200 m. The CPUE distribution was dense when the temperature range of the upper boundary of the thermocline was 27.5–29.5 °C, and the intensity was 0.08–0.13 °C·m−1. The upper-boundary temperature had the greatest impact on the CPUE. The eastward shift of the CPUE during El Niño and the westward shift during La Niña were associated with the optimal thermocline parameter values. The factor of year had a fluctuating effect on the CPUE, and the influence of the La Niña years was greater. The areas with high abundance were 5° N–5° S and 150° E–175° E. The results showed that the changes in the thermocline caused by abnormal climate events significantly affected the CPUE.
... While more information about the diet can provide important insights about predator-prey relationships (Al Kamel and Kara 2019), a combined approach of parasitological studies and stomach content analysis can be an efficient tool to fill knowledge gaps in Indonesian fish ecology and to work toward better ecosystem-based management plans. Climate change and anthropogenic activities have and likely will in the future impact marine biodiversity (Asch et al. 2018;Worm and Lotze 2021). Changes in marine food webs and zoogeographical distributions of intermediate and final hosts go along with changes in parasite abundance and infection patterns (Shamsi 2021). ...
Despite being an important component of the marine ecosystem and posing health risks to human seafood consumers, fish parasites in Indonesia have yet to be adequately described. Here, we analyzed the diet and metazoan parasite fauna of seven commercial fish species ( Alectis indica , Carangoides chrysophrys , Johnius borneensis , Mene maculata , Trichiurus lepturus , Upeneus asymmetricus , U. moluccensis ) landed in Java, Indonesia. We isolated 11 endoparasite species, established 22 new host and 14 new locality records, and extended parasitological records of A. indica by 24%, C. chrysophrys by 25%, J. borneensis by 40%, M. maculata by 44%, U. asymmetricus by 100%, and U. moluccensis by 17%. We genetically identified the trematode Stephanostomum cf. uku (of Bray et al. 2005) from Alecta indica for the first time in Indonesia and provided the sequence of its 28S marker. Stomach content analysis revealed seven different prey items, and the examined fish species were grouped into four feeding categories, which differed significantly in their respective endoparasite fauna. All but two examined fish species hosted potentially zoonotic nematodes, which reveal a risk for parasite-borne diseases in Indonesian food fishes and call for more consequent monitoring with regard to seafood safety in this region. With this study, we were able to establish an association between the feeding ecology and the endoparasite fauna of marine fishes which will help to better understand the transmission pathways of (potentially zoonotic) parasites in food fishes in tropical waters.
... Growing anthropogenic and climate stressors are driving ecological changes with profound global consequences (Cardinale et al., 2012;Johnson et al., 2017;Malhi et al., 2020). As highlighted by recent events, biodiversity losses are not only an environmental emergency, but can have widespread effects by contributing to disease outbreaks (Roe, 2019), and to the collapse of entire ecosystems and the services provided (Asch et al., 2018;IPBES, 2019). Tropical areas, which simultaneously exhibit low resistance/resilience to climate change, and mounting pressures on natural resources linked to their rapid economic and demographic growth, are especially vulnerable to ecological changes (Barlow et al., 2018;Cinner et al., 2018). ...
Non-random community changes are becoming more frequent in many ecosystems. In coral reefs, changes towards communities dominated by other than hard corals are increasing in frequency, with severe impacts on ecosystem functioning and provision of ecosystem services. Although new research suggests that a variety of alternative communities (i.e. not dominated by hard corals) exist, knowledge on the global diversity and functioning of alternative coral reef benthic communities, especially those not dominated by algae, remains scattered. In this systematic review and meta-analysis of 523 articles, we analyse the different coral reef benthic community changes reported to date and discuss the advantages and limitations of the methods used to study these changes. Furthermore, we used field cover data (1116 reefs from the ReefCheck database) to explore the biogeographic and latitudinal patterns in dominant benthic organisms. We found a mismatch between literature focus on coral-algal changes (over half of the studies analysed) and observed global natural patterns. We identified strong biogeographic patterns, with the largest and most biodiverse biogeographic regions (Western and Central Indo-Pacific) presenting previously overlooked soft-coral-dominated communities as the most abundant alternative community. Finally, we discuss the potential biases associated with methods that overlook ecologically important cryptobenthic communities and the potential of new technological advances in improving monitoring efforts. As coral reef communities inevitably and swiftly change under changing ocean conditions, there is an urgent need to better understand the distribution, dynamics as well as the ecological and societal impacts of these new communities.
Microbes as Agents of Change for Sustainable Development explores the pivotal role of microbes and microbiomes in restoring degraded ecosystems and advancing sustainable practices. This comprehensive resource bridges cutting-edge research and practical solutions, emphasizing microbial applications in ecosystem restoration, renewable energy, waste management, agriculture, and climate change mitigation. The book, which spans 22 chapters, provides insights into topics like nutrient cycling, bioremediation, biofertilizers, and microbial genomics. It also highlights innovative approaches, such as microbial fuel cells, pollution monitoring with biosensors, and the role of microbes in GHG emission mitigation. Key Features: - Explores the UN Decade on Ecosystem Restoration and the socio-economic benefits of microbes. - Discusses microbial roles in polluted ecosystem restoration and renewable energy production. - Highlights microbes` contribution to sustainable agriculture, waste management, and climate action.
The exceptional diversity of shallow‐water marine fishes contributes to the nutrition of millions of people worldwide through coastal wild‐capture fisheries, with different species having diverse nutritional profiles. Fishes in ecosystems are reservoirs of micronutrients with benefits to human health. Yet, the amount of micronutrients contained in fish species on coral reefs and in shallow tropical waters is challenging to estimate, and the micronutrients caught by fisheries remain uncertain.
To assess whether micronutrient deficiencies could be addressed through specific fisheries management actions, we first require a quantification of the potentially available micronutrients contained in biodiverse reef fish assemblages. Here, we therefore undertake a broad heuristic assessment of available micronutrients on tropical reefs using ensemble species distribution modelling and identify potential mismatches with micronutrients derived from summarising coastal fisheries landings data.
We find a mismatch between modelled estimates of micronutrients available in the ecosystem on the one hand and the micronutrients in small‐scale fisheries landings data. Fisheries had lower micronutrients than expected from fishes in the modelled assemblage. Further, fisheries were selective for vitamin A, thus resulting in a trade‐off with other micronutrients. Our results remained unchanged after accounting for the under‐sampling of fish communities and under‐reporting of small‐scale fisheries catches—two major sources of uncertainty.
This reported mismatch indicates that current estimates of fished micronutrients are not adequate to fully assess micronutrient inventories. However, small‐scale fisheries in some countries were already selective towards micronutrient mass, indicating policies that target improved access, distribution and consumption of fish could leverage this existing high micronutrient mass.
Enhanced taxonomic resolution of catches and biodiversity inventories using localised species consumption surveys could improve understanding of nature‐people linkages. Improving fisheries reporting and monitoring of reef fish assemblages will advance the understanding of micronutrient mismatches, which overall indicate a weak uptake of nutritional goals in fisheries practices.
The decoupling between micronutrients in ecosystems and in fisheries catches indicates that social, economic, and biodiversity management goals are not shaped around nutritional targets—but this is key to achieve a sustainable and healthy planet for both people and nature.
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Ensuring the conservation and sustainability of marine ecosystems and the continued provision of ecosystem services are key goals of Canada’s framework for its protected seascape sites. With rapid climate change however, the protected seascape sites may become less effective at fulfilling these goals, especially since no consistent and coherent approach exists for adapting marine protected area networks to respond to ongoing and accelerating changes in Canadian marine ecosystems. In this thesis, I project and evaluate the consequences of climate-change induced shifts in marine species compositions for Canada’s east coast and for its proposed Scotian Shelf-Bay of Fundy Bioregion marine protected area network. In addition to assessing the effects of changing species distributions on the protected seascape, I develop a novel approach to project the ecological disruption that may be caused by these shifts. Ultimately, future scenarios with higher carbon emissions had larger shifts in species compositions and, subsequently, higher projected ecological disruption than lower emission scenarios. However, the network sites with the largest shifts in species composition did not suffer the highest ecological disruption, indicating the importance of assessing both species and functional change for a fuller understanding of climate change impacts. To ensure representation across the range of changes projected, I developed a “portfolio” of protected seascape sites that I recommend be prioritized for building resiliency and robustness to climate change, while also identifying the sites projected to have the highest ecological disruption and thus, most in need of protection from additional anthropogenic stressors. My results can be used to inform adaptive climate management for this region, and also provide a template for how such strategies can be conceived in terms of their integration into marine protected area design, management, and operation in other parts of the world.
Biodiversity patterns are fundamental in our understanding of the distribution of life, ecosystem function, and conservation. In this concept analysis, A survey of the existing knowledge on marine biodiversity patterns and drivers across latitudes, longitudes, and depths indicates that none of the postulated patterns represent a rule. The paradigm of latitudinal gradients or bathymetric patterns of diversity vary across biogeographic regions or biodiversity components, kingdoms, or body sizes. The same holds true for the hypothesized longitudinal and cost‐offshore patterns. Food availability and temperature influence all life forms and appear to be the most relevant factors shaping marine biodiversity. However, these drivers interact with many other variables such as spatial heterogeneity, ecological and physical processes creating a complex mosaic of shaping factors that limits any prediction. Climate change, with its implications for global primary productivity and temperature rise, can represent one of the major influences on future marine biodiversity. Understanding biodiversity emphasizes the need to complete the census of marine life in the next decade. The effort must use the most advanced technologies, develop holistic approaches and promote the integration of morphological‐ and genetic‐based taxonomy to explore the biodiversity of organisms of all size classes, at large spatial scales and across habitat types, particularly open ocean and deep‐sea ecosystems. Without this basic knowledge, coupled with identification of the drivers shaping the observed patterns, we will be unable to fill these knowledge gaps that are crucial for developing adequate conservation measures of marine biodiversity at global scale.
The dynamic of marine environmental parameters affects the distribution of commercial tuna in the sea of the maritime continent. Hence, the objectives of this study are to develop spatial distribution models for the four main tuna species in the Maritime continent's sea with reasonable accuracy, identify their correlation with marine environmental parameters, and investigate areas of interaction between those tuna species. The study develops the distribution models for albacore (Thunnus alalunga), bigeye (Thunnus obesus), yellowfin (Thunnus albacares), and skipjack (Katsuwonus pelamis) tuna species, utilizing multi-sensor satellite remote sensing and maximum entropy. The results show models have good performance, focusing on environmental factors such as sea surface temperature (SST), chlorophyll-a (CHL), and sea surface height anomalies (SSHA), combined with eddy kinetic energy (EKE). Seasonal variations in potential tuna habitats are revealed, emphasizing the influence of those marine environmental conditions. From December to May, the four commercial tuna species were distributed in conditions characterized by SST of 26–31.5 °C, CHL levels of 0–3 mg/l, SSHA of −0.3 to 0.2 m, and EKE of 0–1 m2/s2, while from June to November, they experienced SST of 23–31 °C, CHL levels of 0–4 mg/l, SSHA of −0.5 to 0.3 m, and EKE of 0–1.1 m2/s2. The spatial persistence of the four tuna species emerged mainly around the south sea of Java, with skipjack being the most common species found in the sea of the maritime continent. With sufficient and evenly distributed tuna presence records, the results indicate the potential for extrapolation beyond the training data to estimate habitat suitability for the four commercial tuna distributions. The results also suggest potential competition between tuna species sharing ecological niches and highlight possible overlapping areas where different tuna species interact with the same fishing gear.
Marine protected areas (MPAs) are the most widely applied tool for marine biodiversity conservation, yet many gaps remain in our understanding of their species‐specific effects, partly because the socio‐environmental context and spatial autocorrelation may blur and bias perceived conservation outcomes. Based on a large data set of nearly 3000 marine fish surveys spanning all tropical regions of the world, we build spatially explicit models for 658 fish species to estimate species‐specific responses to protection while controlling for the environmental, habitat and socio‐economic contexts experienced across their geographic ranges. We show that the species responses are highly variable, with ~40% of fishes not benefitting from protection. When investigating how traits influence species' responses, we find that rare top‐predators and small herbivores benefit the most from MPAs while mid‐trophic level species benefit to a lesser extent, and rare large herbivores experience adverse effects, indicating potential trophic cascades.
Masyarakat pesisir menghasilkan limbah domestik anorganik maupun organik. Limbah tersebut sebagian tertahan dan terendapkan pada ekosistem lamun dan terdekomposisi yang menyebabkan pelepasan gas CO2. Penelitian ini bertujuan untuk menganalisis hubungan kepadatan lamun dan emisi gas CO2 yang ada di pesisir Negeri Waai, Kabupaten Maluku Tengah. Metode penelitian menggunakan sungkup silinder dan analisis emisi gas mengacu pada hasil analisa kromatografi gas (GC-MS). Hasil penelitian menunjukkan bahwa emisi CO2 terbesar pada stasiun I ditemukan pada spesies C. rotundata yaitu 55.91 mg/m2/jam dan yang terendah pada spesies E. acoroides yaitu 5.51 mg/m2/jam. Sementara pada stasiun II dan III, emisi terbesar ditemukan pada spesies T. hemprichii dengan nilai masing – masing sebesar 66.68 mg/m2/jam dan 33.57 mg/m2/jam. Sementara itu, hubungan kepadatan lamun jenis E. acoroides terhadap emisi CO2 diformulasikan dengan y = 11,318x – 8,3343 dan tingkat korelasi sangat kuat (r = 0,93). Hal yang serupa terlihat pada lamun jenis C. rotundata dan T. hemprichii dengan persamaan regresi linier masing – masing y = 14,284x + 10,751 (r = 0,9629) dan y = 19.085x (r = 0,96). Hal tersebut menunjukkan semakin padat lamun, maka semakin banyak bahan organik yang dapat didekomposisi untuk pembentukan emisi CO2. Selain itu, emisi yang tinggi juga dapat dipengaruhi oleh epifit mikroalga yang melakukan respirasi sehingga memicu peningkatan emisi CO2 di atmosif.
Marine structure changes as a result of climate change, with potential biological implications for human societies and marine ecosystems. These changes include changes in temperatures, flow, discrimination, nutritional inputs, oxygen availability, and acidification of the ocean. In this study, a fractional-order model is constructed using the Caputo fractional operator, which singular and nol-local kernel. A model examines the effects of accelerating global warming on aquatic ecosystems while taking into account variables that change over time, such as the environment and organisms. The positively invariant area also demonstrates positive, bounded solutions of the model treated. The equilibrium states for the occurrence and extinction of fish populations are derived for a feasible solution of the system. We also used fixed-point theorems to analyze the existence and uniqueness of the model. The generalized Ulam-Hyers-Rassias function is used to analyze the stability of the system. To study the impact of the fractional operator through computational simulations, results are generated employing a two-step Lagrange polynomial in the generalized version for the power law kernel and also compared the results with an exponential law and Mittag Leffler kernel. We also produce graphs of the model at various fractional derivative orders to illustrate the important influence that the fractional order has on the different classes of the model with the memory effects of the fractional operator. To help with the oversight of fisheries, this research builds mathematical connections between the natural world and aquatic ecosystems.
Climate change is affecting the ocean, altering the biogeography of marine species. Yet marine protected area (MPA) planning still rarely incorporates projected species range shifts. We used the outputs of species distribution models fitted with biological and climate data as inputs to identify trends in occurrence for marine species in British Columbia (BC), Canada. We assessed and compared two ways of incorporating climate change projections into MPA planning. First, we overlaid 98 species with modelled distributions now and by the mid-21st century under two contrasting (“no mitigation” and “strong mitigation”) climate change scenarios with existing Provincial marine parks in BC, to ask which species could overlap with protected areas in the future. Second, we completed a spatial prioritization analysis using Marxan with the projected future species ranges as inputs, to ask where priority regions exist for the 98 marine species. We found that many BC marine parks will lose species in both climate scenarios that we analyzed, and that protecting 30% of important marine species will be challenging under the “no mitigation” climate change scenario. Challenges included the coarse resolution of the data and uncertainty in projecting species range shifts.
Seasonal fluxes of CO2, CH4, and N2O greenhouse gases in each mangrove species on West Muna Regency-Southeast Sulawesi, Indonesia, conducted in 2019. The most significant CO2 gas flux occurred in April (rainy season) in B. cylindrica species with a flux value of 79.29 mg m-2 h-1, while the lowest CO2 gas flux occurred in July (the dry season) in S. alba species with a flux of 6.32 mg m-2 h-1. The most significant CH 4 gas flux occurred in April (rainy season) in R. mucronata species at 57.16 mg m-2 h-1. The lowest occurred in July (dry season) in species B. gymnorrhiza at 11.38 mg m-2 h-1. The largest N 2 O gas flux occurred in June (dry season) in S. alba species at 6.08 mg m-2 h-1, and the lowest occurred in July (dry season) in B. cylindrica species at 0.43 mg m-2 h-1. Rain duration is highly correlated with CO 2 gas flux in B. cylindrica and B. gymnorrhiza species and CH 4 gas flux in R. mucronata and S. alba species with correlation values of r = 0.6318, r = 5071, r = 0, 6371 and r = 0.5076. Rain duration does not correlate with N 2 O gas flux in S. alba and B. gymnorrhiza species with correlation values of r = 0,0002 and r = 0.0003, respectively.
Phenological shifts have been observed among marine species due to climate change. Modeling changes in fish spawning aggregations (FSAs) under climate change can be useful for adaptive management, because it can allow managers to adjust conservation strategies in the context of specific life history and phenological responses. We modeled effects of climate change on the distribution and phenology of Caribbean FSAs, examining 4 snapper and 4 grouper species. An ecological niche model was used to link FSAs with environmental conditions from remote sensing and project FSA distribution and seasonality under RCP8.5. We found significant differences between groupers and snappers in response to warming. While there was variation among species, groupers experienced slight delays in spawning season, a greater loss of suitable ocean habitat (average loss: 72.75%), and poleward shifts in FSA distribution. Snappers had larger shifts towards earlier phenology, with a smaller loss of suitable ocean habitat (average loss: 24.25%), excluding gray snapper, which gained habitat. Snappers exhibited interspecific variability in latitudinal distribution shifts. Snapper FSAs appeared more resilient to climate change and occupy wider and warmer spawning temperature ranges, while groupers prefer cooler spawning seasons. Consequently, groupers may lose more suitable ocean spawning habitat sooner due to climate change. When comparing species, there were trade-offs among climate change responses in terms of distribution shifts, phenology changes, and declines in habitat suitability. Understanding such trade-offs can help managers prioritize marine protected area locations and determine the optimal timing of seasonal fishing restrictions to protect FSAs vulnerable to fishing pressure in a changing climate.
Under global environmental change, understanding the interactions between people and nature has become critical for human survival. Comparative research can identify trends within social-ecological systems providing key insights for both environmental and developmental research. Island systems, with clear land boundaries, have been proposed as ideal case studies for comparative research, but it is unclear to what extent their potential has been fulfilled. To summarize existing research and identify potential gaps and new directions, we reviewed comparative environmental and developmental research on Pacific Large Ocean States. A diversity of case study locations and research themes were addressed within the sample of reviewed studies. Within the reviewed literature climate change, energy infrastructure, trade and fisheries were key themes of environmental and developmental research compared between island systems. Research was biased towards wealthier Pacific Large Ocean States and those with a relatively higher degree of socio-economic development. Our review highlights the potential value of a stronger a priori inclusion of spatial scale and conceptual frameworks, such as spatial resilience, to facilitate generalization from case studies.
The Pacific Islands Fisheries Science Center conducted a climate change vulnerability assessment for six species groups in the Pacific Islands region (Giddens et al. unpublished). This data report summarizes the following assessments of each species in the deep slope species group: overall climate vulnerability rank (certainty determined by bootstrap following Hare et al. 2016), climate exposure, biological sensitivity, distributional vulnerability rank, data quality, climate effects on abundance and distribution, and life history (see Morrison et al. 2015 for further details).
For many people living in low-income coastal communities, marine resources provide a crucial source of animal protein and are of major nutritional importance. However, because of various human-induced pressures, such as overfishing and poor resource management, marine resources are deteriorating at an unprecedented rate. Climate change effects this dynamic by contributing directly to marine resource deterioration and acting as an effect multiplier, worsening already-present problems in the systems. This deterioration threatens the viability of marine resources to support future food security demands and presents multiple health implications for coastal communities that rely upon these resources. This research used a narrative review to explore how the impacts of climate change are projected to impact human health and sustainable development throughout subsistence fishing communities. A case study approach focusing on the Pacific Ocean region of Micronesia was conducted to provide a practical indication of the future scenario applicable to other geographical regions across the globe. The results indicate that climate change is likely to exacerbate adverse health outcomes such as food insecurity, ciguatera fish poisoning, heatstroke, and mental health problems and that climate change may lead to the deterioration of traditional cultural practices. As the climate crisis is happening now and will be an issue extending into the foreseeable future, it is necessary to implement adaptation strategies, funding, and governance to limit global emissions, preserve marine resources, and support human well-being. Therefore, this research details adaptation strategies, such as diversifying fish catch and reviving traditional postharvest preservation methods, that may help communities adapt to climate change.
Significance Statement
The Sixth Assessment Report by the Intergovernmental Panel on Climate Change (2021) has indicated that marine resources are deteriorating at an unprecedented rate across all regions of the globe. As marine resources significantly contribute to feeding coastal–semisubsistence communities, it is beneficial to understand how this deterioration will affect human health. Thus, this research indicates that declines in marine resources may exacerbate the prevalence of food insecurity, ciguatera fish poisoning, heat-related illnesses, mental health problems, and chronic diseases within marine-dependent communities. Furthermore, this research details adaptation strategies such as diversifying fish catch, improving postharvest preservation methods, and offering counseling services, which may help support the health and well-being of marine-dependent communities.
Environmental crises often stem back to how humans make decisions and behave. Thus, the extent to which we can successfully address these challenges will depend on the extent to which we can design and deliver effective behavioral change interventions. This project examines how complex behavioral change interventions can be applied to modify human behavior of villagers living in coastal communities. Our work aimed to increase adoption of sustainable behaviors, protect marine biodiversity, improve community wellbeing, increase individual psychosocial skills and executive functions, and increase communal resiliency and adaptability. We conducted pilot and feasibility efficacy trials in two low‐resource coastal communities in Indonesia and Philippines. We used a single site case study and a quasi‐experimental design with control‐treatment matching to evaluate the intervention. Results include increased sustainable behaviors (e.g., recycling), increased prosocial behaviors (e.g., positive communication), and increased perceptions of empowerment for groups exposed to the intervention.
Resilience of food systems is key to ensuring food security through crisis. The COVID-19 pandemic presents an unprecedented shock that reveals varying levels of resilience of increasingly interconnected food systems across the globe. We contribute to the ongoing debate about whether increased connectivity reduces or enhances resilience in the context of rural Pacific food systems, while examining how communities have adapted to the global shocks associated with the pandemic to ensure food security. We conducted 609 interviews across 199 coastal villages from May to October 2020 in Federated States of Micronesia, Fiji, Palau, Papua New Guinea, Solomon Islands, Tonga, and Tuvalu to understand community-level impacts and adaptations during the first 5–10 months of the COVID-19 crisis. We found that local food production practices and food sharing conferred resilience, and that imported foods could aid or inhibit resilience. Communities in countries more reliant on imports were almost twice as likely to report food insecurity compared to those least reliant. However, in places dealing with a concurrent cyclone, local food systems were impaired, and imported foods proved critical. Our findings suggest that policy in the Pacific should bolster sustainable local food production and practices. Pacific states should avoid becoming overly reliant on food imports, while having measures in place to support food security after disasters, supplementing locally produced and preserved foods with imported foods when necessary. Developing policies that promote resilient food systems can help prepare communities for future shocks, including those anticipated with climate change.
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future.
Coral reefs support immense biodiversity and provide important ecosystem services to many millions of people. Yet reefs are degrading rapidly in response to numerous anthropogenic drivers. In the coming centuries, reefs will run the gauntlet of climate change, and rising temperatures will transform them into new configurations, unlike anything observed previously by humans. Returning reefs to past configurations is no longer an option. Instead, the global challenge is to steer reefs through the Anthropocene era in a way that maintains their biological functions. Successful navigation of this transition will require radical changes in the science, management and governance of coral reefs.
Previous studies highlight the winners and losers in fisheries under climate change based on shifts in biomass, species composition and potential catches. Understanding how climate change is likely to alter the fisheries revenues of maritime countries is a crucial next step towards the development of effective socio-economic policy and food sustainability strategies to mitigate and adapt to climate change. Particularly, fish prices and cross-oceans connections through distant water fishing operations may largely modify the projected climate change impacts on fisheries revenues. However, these factors have not formally been considered in global studies. Here, using climate-living marine resources simulation models, we show that global fisheries revenues could drop by 35% more than the projected decrease in catches by the 2050 s under high CO2 emission scenarios. Regionally, the projected increases in fish catch in high latitudes may not translate into increases in revenues because of the increasing dominance of low value fish, and the decrease in catches by these countries’ vessels operating in more severely impacted distant waters. Also, we find that developing countries with high fisheries dependency are negatively impacted. Our results suggest the need to conduct full-fledged economic analyses of the potential economic effects of climate change on global marine fisheries.
Christopher Golden and colleagues calculate that declining numbers of marine fish will spell more malnutrition in many developing nations.
Background: Pacific Island countries and territories (PICTs) face a double burden of disease, with a high prevalence of household food insecurity and childhood micronutrient deficiencies, accompanied by a burgeoning increase in adult obesity, diabetes and heart disease.
Methods: A systematic literature review was undertaken to assess whether increased availability of, and access to, fish improves a) household food security and b) individual nutritional status.
Results: A total of 29 studies were reviewed. Fourteen studies identified fish as the primary food source for Pacific Islanders and five studies reported fish/seafood as the primary source of dietary protein. Fish consumption varied by cultural sub-region and Pacific Island countries and territories. Fish consumption and nutritional status was addressed in nine studies, reporting moderate iodine deficiency in Vanuatu where only 30 % of participants consumed mostly fresh fish. Similarly, the degree to which Pacific Islanders depended on fishing for household income and livelihood varied between and within PICTs. For more economically developed countries, household income was derived increasingly from salaried work and dependency on fishing activities has been declining.
Conclusions: Fishing remains a major contributor to food security in PICTs, through subsistence production and income generation. However, there is a paucity of research aimed at assessing how maintaining and/or improving fish consumption benefits the diets and health of Pacific Islanders as they contend with the ongoing nutrition transition that is characterised by an increasing demand for packaged imported foods, such as canned meats, instant noodles, cereals, rice, and sugar-sweetened beverages, with subsequent decreased consumption of locally-produced plants and
animals.
model ensemble projections of climate change effects on global marine biodiversity. – ICES Species distribution models (SDMs) are important tools to explore the effects of future global changes in biodiversity. Previous studies show that variability is introduced into projected distributions through alternative datasets and modelling procedures. However, a multi-model approach to assess biogeographic shifts at the global scale is still rarely applied, particularly in the marine environment. Here, we apply three commonly used SDMs (AquaMaps, Maxent, and the Dynamic Bioclimate Envelope Model) to assess the global patterns of change in species richness, invasion, and extinction intensity in the world oceans. We make species-specific projections of distribution shift using each SDM, subsequently aggregating them to calculate indices of change across a set of 802 species of exploited marine fish and invertebrates. Results indicate an average poleward latitudinal shift across species and SDMs at a rate of 15.5 and 25.6 km decade 21 for a low and high emissions climate change scenario, respectively. Predicted distribution shifts resulted in hotspots of local invasion intensity in high latitude regions, while local extinctions were concentrated near the equator. Specifically, between 108N and 108S, we predicted that, on average, 6.5 species would become locally extinct per 0.58 latitude under the climate change emissions scenario Representative Concentration Pathway 8.5. Average invasions were predicted to be 2.0 species per 0.58 latitude in the Arctic Ocean and 1.5 species per 0.58 latitude in the Southern Ocean. These averaged global hotspots of invasion and local extinction intensity are robust to the different SDM used and coincide with high levels of agreement.
Significance
In terrestrial ecosystems, earlier phenology (i.e., seasonal timing) is a hallmark organismal response to global warming. Less is known about marine phenological responses to climate change, especially in Eastern Boundary Current Upwelling (EBCU) ecosystems that generate >20% of fish catch. The phenology of 43 EBCU fish species was examined over 58 years; 39% of phenological events occurred earlier in recent decades, with faster changes than many terrestrial ecosystems. Zooplankton did not shift their phenology synchronously with most fishes. Fishes that aren’t changing their phenology synchronously with zooplankton may be subject to mismatches with prey, potentially leading to reduced recruitment to fisheries. Adjusting the timing of seasonal management tactics (e.g., fishery closures, hatchery releases) may help ensure that management remains effective.
The ocean moderates anthropogenic climate change at the cost of profound alterations of its physics, chemistry, ecology, and services. Here, we evaluate and compare the risks of impacts on marine and coastal ecosystems-and the goods and services they provide-for growing cumulative carbon emissions under two contrasting emissions scenarios. The current emissions trajectory would rapidly and significantly alter many ecosystems and the associated services on which humans heavily depend. A reduced emissions scenario-consistent with the Copenhagen Accord's goal of a global temperature increase of less than 2°C-is much more favorable to the ocean but still substantially alters important marine ecosystems and associated goods and services. The management options to address ocean impacts narrow as the ocean warms and acidifies. Consequently, any new climate regime that fails to minimize ocean impacts would be incomplete and inadequate.
Copyright © 2015, American Association for the Advancement of Science.
Marine ecosystems are increasingly impacted by human-induced changes. Ocean
ecosystem drivers – including warming, acidification, deoxygenation and perturbations
to biological productivity – can co-occur in space and time, but detecting their trends is complicated by the presence of noise associated with natural variability in the climate
system. Here we use Large Initial-Condition Ensemble Simulations with a comprehensive
Earth System Model under a historical/RCP8.5 pathway over 1950–2100 to consider
emergence characteristics for the four individual and combined drivers. Using a
one-standard deviation (67% confidence) threshold of signal-to-noise to define emergence with a 30 yr trend window, we show that ocean acidification emerges much earlier
than other drivers, namely during the 20th century over most of the global ocean.
For biological productivity, the anthropogenic signal does not emerge from the noise
over most of the global ocean before the end of the 21st century. The early emergence
pattern for sea surface temperature in low latitudes is reversed from that of subsurface oxygen inventories, where emergence occurs earlier in the Southern Ocean. For
the combined multiple-driver field, 41% of the global ocean exhibits emergence for the
2005–2014 period, and 63% for the 2075–2084 period. The combined multiple-driver
field reveals emergence patterns by the end of this century that are relatively high over
much of the Southern Ocean, North Pacific, and Atlantic, but relatively low over the
tropics and the South Pacific. In regions with pronounced emergence characteristics,
marine ecosystems can be expected to be pushed outside of their comfort zone determined
by the degree of natural background variability to which they are adapted. The
results here thus have implications not only for optimization of the ocean observing
system, but also for risk assessment and mitigation strategies.
Projections of equatorial sea surface temperature from CMIP5 climate models are important for understanding possible future changes in marine habitats, local rainfall and climate processes such as El Niño Southern Oscillation. Interpreting the projected changes in the tropical Pacific is complicated by the systematic cold tongue bias and overly westward location of the warm pool edge at the equator in coupled models. Here an index based on the maximum zonal salinity gradient is used to differentiate the warm pool from the cold tongue in each of 19 CMIP5 models. Warming is then calculated relative to the dynamic edge of the warm pool between the second halves of the 20th and 21st Centuries from the RCP8.5 scenario to provide a bias adjusted SST projection.Based on this definition of the edge, while the warm pool edge is projected to warm, it is likely to remain within 10° of its present longitude. This is in stark contrast to the large projected eastward displacements of the isotherms that are usually used to define the edge. Adjusting for the edge, warming within the warm pool is projected to be fairly uniform with surface water freshening. Projected warming is enhanced over the cold tongue with the net effect of reducing the zonal SST gradient. In contrast, if the warming is calculated without correcting for the edge of the warm pool, the warming signature is dominated by the poorer performing models with an overly westward warm pool, resulting in enhanced warming across the equatorial Pacific. Bias adjusting realigns the warming signature and reduces the model spread of projected warming. The biased warming signature also introduces spurious meridional and zonal SST gradients. This will potentially alter the behaviour of the atmospheric convergence zones and the dynamics of ENSO which is influenced by the extent of the warm pool and zonal SST gradients.
The Western Pacific Warm Pool is a region of high tuna catch, and how future climate change might impact the tuna fisheries is an important regional issue. By using a high-resolution ocean model forced by the simulated climate of the 2060s, we investigate whether enhanced spatial resolution and bias correction of the mean state could alter the climate change projection for the western tropical Pacific and examine the consequences this might have for tropical tuna distributions. For most of the physical environmental variables, enhanced resolution and bias correction had only a minor impact on the projected changes. The climate projections showed a maximum surface warming east of the Warm Pool, a shoaling of the thermocline in the Warm Pool, and an eastward expansion of the Warm Pool. In the Warm Pool, the shoaling of the thermocline raises the nutricline into the photic zone and increases phytoplankton and primary productivity, a feature that is most evident in the high-resolution model projection but also weakly present in the coarse-resolution projection. The phytoplankton and primary productivity response to climate change was where ocean model resolution produced a clear difference. With enhanced resolution, the simulation had stronger and better-defined zonal currents, which were more consistent with observations. Along the equator, the high-resolution model enabled vertical current shear mixing to generate a sub-surface phytoplankton maximum both inside and outside the Warm Pool, which is an observed phenomenon. With climate change, the enhanced-resolution model projected enhanced vertical shear mixing, increased vertical supply of nutrients to the photic zone, and increased sub-surface phytoplankton concentrations. The increase in sub-surface phytoplankton concentrations helps to offset the decline in surface phytoplankton concentrations and results in a projection of almost no change in the western tropical Pacific primary productivity. In contrast, the low-resolution model projected a substantial reduction in phytoplankton concentrations and primary productivity; such a response is typical of climate change projections for the region. Importantly, enhanced resolution dramatically altered the projected response of phytoplankton and primary productivity to climate change. Using the enhanced-resolution model, the projected increase in the Warm Pool with little change in primary productivity and in suitable habitat for skipjack tuna suggest that by the 2060s climate change will not have a large impact on skipjack tuna fisheries.
The reorganization of patterns of species diversity driven by anthropogenic climate change, and the consequences for humans, are not yet fully understood or appreciated. Nevertheless, changes in climate conditions are useful for predicting shifts in species distributions at global and local scales. Here we use the velocity of climate change to derive spatial trajectories for climatic niches from 1960 to 2009 (ref. 7) and from 2006 to 2100, and use the properties of these trajectories to infer changes in species distributions. Coastlines act as barriers and locally cooler areas act as attractors for trajectories, creating source and sink areas for local climatic conditions. Climate source areas indicate where locally novel conditions are not connected to areas where similar climates previously occurred, and are thereby inaccessible to climate migrants tracking isotherms: 16% of global surface area for 1960 to 2009, and 34% of ocean for the 'business as usual' climate scenario (representative concentration pathway (RCP) 8.5) representing continued use of fossil fuels without mitigation. Climate sink areas are where climate conditions locally disappear, potentially blocking the movement of climate migrants. Sink areas comprise 1.0% of ocean area and 3.6% of land and are prevalent on coasts and high ground. Using this approach to infer shifts in species distributions gives global and regional maps of the expected direction and rate of shifts of climate migrants, and suggests areas of potential loss of species richness.
The physical climate formulation and simulation characteristics of two new global coupled carbon-climate Earth System Models, ESM2M and ESM2G, are described. These models demonstrate similar climate fidelity as the Geophysical Fluid Dynamics Laboratory's previous Climate Model version 2.1 (CM2.1) while incorporating explicit and consistent carbon dynamics. The two models differ exclusively in the physical ocean component; ESM2M uses Modular Ocean Model version 4p1 with vertical pressure layers while ESM2G uses Generalized Ocean Layer Dynamics with a bulk mixed layer and interior isopycnal layers. Differences in the ocean mean state include the thermocline depth being relatively deep in ESM2M and relatively shallow in ESM2G compared to observations. The crucial role of ocean dynamics on climate variability is highlighted in El Niño-Southern Oscillation being overly strong in ESM2M and overly weak in ESM2G relative to observations. Thus, while ESM2G might better represent climate changes relating to total heat content variability given its lack of long-term drift, gyre circulation, and ventilation in the North Pacific, tropical Atlantic, and Indian Oceans, and depth structure in the overturning and abyssal flows, ESM2M might better represent climate changes relating to surface circulation given its superior surface temperature, salinity, and height patterns, tropical Pacific circulation and variability, and Southern Ocean dynamics. The overall assessment is that neither model is fundamentally superior to the other, and that both models achieve sufficient fidelity to allow meaningful climate and earth system modeling applications. This affords the ability to assess the role of ocean configuration on earth system interactions in the context of two state-of-the-art coupled carbon- climate models.
The authors describe carbon system formulation and simulation characteristics of two new global coupled carbon-climate Earth System Models (ESM), ESM2M and ESM2G. These models demonstrate good climate fidelity as described in part I of this study while incorporating explicit and consistent carbon dynamics. The two models differ almost exclusively in the physical ocean component; ESM2M uses the Modular Ocean Model version 4.1 with vertical pressure layers, whereas ESM2G uses generalized ocean layer dynamics with a bulk mixed layer and interior isopycnal layers. On land, both ESMs include a revised land model to simulate competitive vegetation distributions and functioning, including carbon cycling among vegetation, soil, and atmosphere. In the ocean, both models include new biogeochemical algorithms including phytoplankton functional group dynamics with flexible stoichiometry. Preindustrial simulations are spun up to give stable, realistic carbon cycle means and variability. Significant differences in simulation characteristics of these two models are described. Because of differences in oceanic ventilation rates, ESM2M has a stronger biological carbon pump but weaker northward implied atmospheric CO2 transport than ESM2G. The major advantages of ESM2G over ESM2M are improved representation of surface chlorophyll in the Atlantic and Indian Oceans and thermocline nutrients and oxygen in the North Pacific. Improved tree mortality parameters in ESM2G produced more realistic carbon accumulation in vegetation pools. The major advantages of ESM2M over ESM2G are reduced nutrient and oxygen biases in the southern and tropical oceans.
Ocean ecosystems are increasingly stressed by human-induced changes of
their physical, chemical and biological environment. Among these
changes, warming, acidification, deoxygenation and changes in primary
productivity by marine phytoplankton can be considered as four of the
major stressors of open ocean ecosystems. Due to rising atmospheric
CO2 in the coming decades, these changes will be amplified.
Here, we use the most recent simulations performed in the framework of
the Coupled Model Intercomparison Project 5 to assess how these
stressors may evolve over the course of the 21st century. The 10 Earth
System Models used here project similar trends in ocean warming,
acidification, deoxygenation and reduced primary productivity for each
of the IPCC's representative concentration parthways (RCP) over the 21st
century. For the "business-as-usual" scenario RCP8.5, the model-mean
changes in 2090s (compared to 1990s) for sea surface temperature, sea
surface pH, global O2 content and integrated primary
productivity amount to +2.73 °C, -0.33 pH unit, -3.45% and -8.6%,
respectively. For the high mitigation scenario RCP2.6, corresponding
changes are +0.71 °C, -0.07 pH unit, -1.81% and -2.0% respectively,
illustrating the effectiveness of extreme mitigation strategies.
Although these stressors operate globally, they display distinct
regional patterns. Large decreases in O2 and in pH are
simulated in global ocean intermediate and mode waters, whereas large
reductions in primary production are simulated in the tropics and in the
North Atlantic. Although temperature and pH projections are robust
across models, the same does not hold for projections of sub-surface
O2 concentrations in the tropics and global and regional
changes in net primary productivity.
IPCC-type climate models have produced simulations of the oceanic environment that can be used to drive models of upper trophic levels to explore the impact of climate change on marine resources. We use the Spatial Ecosystem And Population Dynamics Model (SEAPODYM) to investigate the potential impact of Climate change under IPCC A2 scenario on Pacific skipjack tuna (Katsuwonus pelamis). IPCC-type models are still coarse in resolution and can produce significant anomalies, e.g., in water temperature. These limitations have direct and strong effects when modeling the dynamics of marine species. Therefore, parameter estimation experiments based on assimilation of historical fishing data are necessary to calibrate the model to these conditions before exploring the future scenarios. A new simulation based on corrected temperature fields of the A2 simulation from one climate model (IPSL-CM4) is presented. The corrected fields led to a new parameterization close to the one achieved with more realistic environment from an ocean reanalysis and satellite-derived primary production. Projected changes in skipjack population under simple fishing effort scenarios are presented. The skipjack catch and biomass is predicted to slightly increase in the Western Central Pacific Ocean until 2050 then the biomass stabilizes and starts to decrease after 2060 while the catch reaches a plateau. Both feeding and spawning habitat become progressively more favourable in the eastern Pacific Ocean and also extend to higher latitudes, while the western equatorial warm pool is predicted to become less favorable for skipjack spawning.
Ocean biogeochemistry is a novel standard component of fifth phase of the
Coupled Model Intercomparison Project (CMIP5) experiments which project future
climate change caused by anthropogenic emissions of greenhouse gases. Of particular
interest here is the evolution of the oceanic sink of carbon and the oceanic contribution
to the climate-carbon cycle feedback loop. The Hamburg ocean carbon cycle
model (HAMOCC), a component of the Max Planck Institute for Meteorology Earth
system model (MPI-ESM), is employed to address these
challenges. In this paper we describe the version of HAMOCC used in the CMIP5
experiments (HAMOCC 5.2) and its implementation in the MPI-ESM to provide a
documentation and basis for future CMIP5-related studies. Modeled present day distributions
of biogeochemical variables calculated in two different horizontal resolutions
compare fairly well with observations. Statistical metrics indicate that the model
performs better at the ocean surface and worse in the ocean interior. There is a tendency
for improvements in the higher resolution model configuration in representing
deeper ocean variables; however, there is little to no improvement at the ocean surface.
An experiment with interactive carbon cycle driven by emissions of CO2 produces a
25% higher variability in the oceanic carbon uptake over the historical period than the
same model forced by prescribed atmospheric CO2 concentrations. Furthermore, a
climate warming of 3.5 K projected at atmospheric CO2 concentration of four times
the preindustrial value, reduced the atmosphere-ocean CO2 flux by 1 GtC yr21.
Overall, the model shows consistent results in different configurations, being suitable
for the type of simulations required within the CMIP5 experimental design.
Organisms are expected to adapt or move in response to climate change, but observed distribution shifts span a wide range
of directions and rates. Explanations often emphasize biological distinctions among species, but general mechanisms have been
elusive. We tested an alternative hypothesis: that differences in climate velocity—the rate and direction that climate shifts
across the landscape—can explain observed species shifts. We compiled a database of coastal surveys around North America from
1968 to 2011, sampling 128 million individuals across 360 marine taxa. Climate velocity explained the magnitude and direction
of shifts in latitude and depth much more effectively than did species characteristics. Our results demonstrate that marine
species shift at different rates and directions because they closely track the complex mosaic of local climate velocities.
Past meta-analyses of the response of marine organisms to climate change
have examined a limited range of locations, taxonomic groups and/or
biological responses. This has precluded a robust overview of the effect
of climate change in the global ocean. Here, we synthesized all
available studies of the consistency of marine ecological observations
with expectations under climate change. This yielded a meta-database of
1,735 marine biological responses for which either regional or global
climate change was considered as a driver. Included were instances of
marine taxa responding as expected, in a manner inconsistent with
expectations, and taxa demonstrating no response. From this database,
81-83% of all observations for distribution, phenology, community
composition, abundance, demography and calcification across taxa and
ocean basins were consistent with the expected impacts of climate
change. Of the species responding to climate change, rates of
distribution shifts were, on average, consistent with those required to
track ocean surface temperature changes. Conversely, we did not find a
relationship between regional shifts in spring phenology and the
seasonality of temperature. Rates of observed shifts in species'
distributions and phenology are comparable to, or greater, than those
for terrestrial systems.
The Asia-Pacific's Coral Triangle is defined by its extremely high marine biodiversity. Over one hundred million people living in its coastal zones use this biodiversity to support their livelihoods. Hundreds of millions more derive nutritious food directly from the region′s marine resources and through local, regional and global trade. Biodiversity and its values to society are threatened by demographic and habitat change, rising demand, intensive harvesting and climate change. In partnership with international conservation organisations and development funders, the governments of the region′s six countries have come together to develop the Coral Triangle Initiative (CTI) on Coral Reefs, Fisheries and Food Security. The CTI has explicit goals and defined targets for marine biodiversity conservation, but not for the food security of the region′s marine-resource dependent people, despite this being the wider aim used to justify conservation action. This article suggests how the food security aim of the CTI could be made more explicit. It outlines the complex pathways linking marine biodiversity with food security and argues that improved social science analysis, inter-sectoral policy and management interactions are necessary if conserving marine biodiversity is to contribute towards meeting food security challenges in the region.
Most marine teleosts have a pelagic phase during their early life history, but few studies have investigated how the timing of events within the planktonic larval fish assemblage is related to environmental variability. We examined this issue using a data series of 534 larval fish samples collected between 1975 and 1987 in the Western English Channel, near Plymouth, UK. Two sets of species were identified: spring spawning (April to July) and summer spawning (July to September). The timing of appearance of the spring-spawning group in the plankton was significantly dependent on sea temperatures the previous November and December, with earlier appearance during cooler years. We suggest that this could be due to colder years triggering earlier winter migration of adults from cool inshore habitat to warmer offshore overwintering grounds, which in turn results in earlier gonad maturation and spawning. In contrast, the timing of appearance of the summer-spawning group was significantly dependent on sea temperatures the preceding March, with earlier spawning during warmer years. This may be due exclusively to more rapid gonad maturation in offshore waters. These data emphasize that marine fish populations do not always respond uniformly to temperature change. Moreover, since appropriate timing of larval fish appearance in the plankton may be critical for the match or mismatch with essential trophic resources, the thermally induced phenological changes identified have potential to influence annual recruitment success. © The Author 2010. Published by Oxford University Press. All rights reserved.
This study aims to describe a new nonparametric ecological niche model for the analysis of presence-only data, which we use to map the spatial distribution of Atlantic cod and to project the potential impact of climate change on this species. The new model, called the Non-Parametric Probabilistic Ecological Niche (NPPEN) model, is derived from a test recently applied to compare the ecological niche of 2 different species. The analysis is based on a simplification of the Multiple Response Permutation Procedures (MRPP) using the Generalised Mahalanobis distance. For the first time, we propose to test the generalized Mahalanobis distance by a non-parametric procedure, thus avoiding the arbitrary selection of quantile classes to allow the direct estimation of the probability of occurrence of a species. The model NPPEN was applied to model the ecological niche (sensu Hutchinson) of Atlantic cod and therefore its spatial distribution. The modelled niche exhibited high probabilities of occurrence at bathymetry ranging from 0 to 500 m (mode from 100 to 300 m), at annual sea surface temperature of from -1 to 14 degrees C (mode from 4 to 8 degrees C) and at annual sea surface salinity ranging from 0 to 36 (mode from 25 to 34). This made the species a good indicator of the sub-arctic province. Current climate change is having a strong effect on North Sea cod and may have also reinforced the negative impact of fishing on stocks located offshore of North America. The model shows a pronounced effect of present-day climate change on the spatial distribution of Atlantic cod. Projections for the coming decades suggest that cod may eventually disappear as a commercial species from regions where a sustained decrease or collapse has already been documented. In contrast, the abundance of cod is likely to increase in the Barents Sea.
Maintaining the level of fish consumption in Pacific Island countries recommended for good nutrition as the populations of coastal communities grow, and as coral reefs are degraded by global warming and ocean acidification, will depend on small-scale fishers catching more tuna and other large pelagic fish. Concerted research and development by regional agencies shows that nearshore fish aggregating devices (FADs) provide one way for small-scale fishers to make this transition. Although the full potential of FADs remains to be assessed, several investments to optimise their use have been identified. These investments include pinpointing the locations where FADs are likely to make the greatest contributions to nutrition of coastal communities, integrating use of FADs with other livelihood activities, and improving the designs of FADs. Where Pacific Island countries have committed to developing nearshore FAD programmes, additional investments are needed to operationalise the use of FADs, particularly in cyclone-prone countries. These investments include: 1) training in safe and effective FAD-fishing methods; 2) developing reliable ways for forecasting when tuna, and other large pelagic fish (e.g., mahi mahi and wahoo), are likely to associate with FADs and delivering this information to fishers effectively; and 3) storing spare FAD materials, boats and fishing gear in cyclone-proof containers so that FADs lost during cyclones can be replaced quickly. When combined with measures to sustain catches of coastal demersal fish, operationalising the use of nearshore FADs is expected to help several Pacific Island countries attain the food security goals of regional policy frameworks.
Climate and weather have profound effects on economies, the food security and livelihoods of communities throughout the Pacific Island region. These effects are particularly important for small-scale fisheries and occur, for example, through changes in sea surface temperature, primary productivity, ocean currents, rainfall patterns, and through cyclones. This variability has impacts over both short and long time scales. We differentiate climate predictions (the actual state of climate at a particular point in time) from climate projections (the average state of climate over long time scales). The ability to predict environmental conditions over the time scale of months to decades will assist governments and coastal communities to reduce the impacts of climatic variability and take advantage of opportunities. We explore the potential to make reliable climate predictions over time scales of six months to 10 years for use by policy makers, managers and communities. We also describe how climate predictions can be used to make decisions on short time scales that should be of direct benefit to sustainable management of small-scale fisheries, and to disaster risk reduction, in Small-Island Developing States in the Pacific
Marine ecosystems play a central role in economic and social life in the Republic of Palau, a Small Island Developing State in the Western Pacific. Marine resources underpin subsistence and commercial fisheries, as well as tourism activities, contributing substantially to Palau's GDP and employment. Since 1992, Palau has been actively developing conservation initiatives to protect marine resources, promote ecotourism, and ensure revenue generation. Marine reserves represent a particularly important tool in the country's sustainable development strategy. In 2015, Palau designated 80% of its marine EEZ as a National Marine Sanctuary, with the remaining 20% slated for domestic fisheries. That same year, Palau received 160 thousand tourists, over 9 times the country's population. In early 2017, the President proposed a bill effectively limiting budget travel and actively promoting high-end tourism. This study uses a quantitative social-ecological model to explore policy scenarios involving tourism, marine conservation and local food security. While climate change had the largest expected impact on local ecosystems, reef fish consumption contributes considerably to future projected declines in marine resources. Therefore, for Palau to achieve its goals of boosting revenues while sustainably stewarding marine resources, it will be necessary to transfer some level of consumption from reef fish on to tuna and other pelagics. Such changes, which align with the current proposal of developing an offshore national fishery as part of the Sanctuary's management plan, may allow Palau to meet future seafood demand, while protecting reef systems and the industries that rely on them.
Marine benefits of the Paris Agreement
Keeping recent global agreements to limit temperature increases to 1.5° to 2°C above preindustrial levels will have benefits across terrestrial ecosystems. But what about marine ecosystems? Cheung et al. modeled the influence of temperature increases on two key measures of fishery sustainability, catch and species turnover (see the Perspective by Fulton). Limiting temperature increases to 1.5°C substantially improved catch potential and decreased turnover of harvested species. These results provide further support for meeting this important goal.
Science , this issue p. 1591 ; see also p. 1530
The effects of ocean acidification (OA) on the structure and complexity of coastal marine biogenic habitat have been broadly overlooked. Here we explore how declining pH and carbonate saturation may aaect the structural complexity of four major biogenic habitats. Our analyses predict that indirect eeects driven by OA on habitat-forming organisms could lead to lower species diversity in coral reefs, mussel beds and some macroalgal habitats, but increases in seagrass and other macroalgal habitats. Available in situ data support the prediction of decreased biodiversity in coral reefs, but not the prediction of seagrass bed gains. Thus, OA-driven habitat loss may exacerbate the direct negative eeects of OA on coastal biodiversity; however, we lack evidence of the predicted biodiversity increase in systems where habitat-forming species could benefit from acidification. Overall, a combination of direct eeects and community-mediated indirect eeects will drive changes in the extent and structural complexity of biogenic habitat, which will have important ecosystem eeects.
The Fifth Assessment Report of the Intergovernmental Panel on Climate Change highlights that climate change and ocean acidification
are challenging the sustainable management of living marine resources (LMRs). Formal and systematic treatment of uncertainty
in existing LMR projections, however, is lacking. We synthesize knowledge of how to address different sources of uncertainty
by drawing from climate model intercomparison efforts. We suggest an ensemble of available models and projections, informed
by observations, as a starting point to quantify uncertainties. Such an ensemble must be paired with analysis of the dominant
uncertainties over different spatial scales, time horizons, and metrics. We use two examples: (i) global and regional projections
of Sea Surface Temperature and (ii) projection of changes in potential catch of sablefish (Anoplopoma fimbria) in the 21st century, to illustrate this ensemble model approach to explore different types of uncertainties. Further effort
should prioritize understanding dominant, undersampled dimensions of uncertainty, as well as the strategic collection of observations
to quantify, and ultimately reduce, uncertainties. Our proposed framework will improve our understanding of future changes
in LMR and the resulting risk of impacts to ecosystems and the societies under changing ocean conditions.
Commercial fishing involves locating fish in a variable environment, and a fisher’s historical experience with environmental conditions and the influence on fish distribution underpins their economic efficiency. However, in many regions, changing environments are reducing the utility of this experience. In the Great Australian Bight, recent environmental changes have modified the summer distribution of southern bluefin tuna (SBT, Thunnus maccoyii). This has affected the timing and location of fishing activity and contributed to economic impacts, at the same time as international competition is lowering value of the catch. The SBT purse-seine fishery is managed under a strict quota, so catching more fish is not an option to reduce fixed costs; instead fish must be caught more efficiently in a changing environment. Following discussion with industry stakeholders, we developed a seasonal forecast system based on a three stage process. We first assessed needs through discussions with industry. We then developed a SBT habitat forecast system based on a seasonal environmental forecasting model (POAMA: the Predictive Ocean Atmosphere Model for Australia) coupled with a habitat preference model for SBT (developed using data from tagged fish). Based on a historical evaluation of the environmental forecasting model and the habitat model, we expect temperature-based habitat forecasts to have useful skill up to two months into the future during the months of interest. The final stage involved forecast delivery via an industry-specific website and engagement with stakeholders, which led to improved presentation and contextualization of the forecasts. The forecasts, which are updated daily, are now being used by SBT fishers and have proven a useful aid in their decision-making.
Marine biological resources are likely to come under increasing stress over the course of the 21st century as global climate change and ocean acidification interact with other stresses, including heavy fishing pressures and marine pollution, to create far reaching and difficult-to-predict changes in species abundance, spatial distribution, and trophic interactions. The governance systems in place for marine fisheries and for the marine environment, more broadly, will be critical in determining the extent to which these resources can be managed for sustainability. The paper focuses on the governance of internationally shared fisheries, and draws on a body of game-theoretic research to discuss present-day governance problems and to evaluate the implications of global environmental change for future efforts to maintain cooperative and effective governance of shared fishery resources. In particular, the increased likelihood of abrupt and unpredictable changes in the productive potential and migratory behavior of exploited fish stocks may threaten to disrupt cooperative management arrangements. The paper discusses the value of contingency planning based on anticipation of the possibility of such events and concludes with a discussion of future directions for both research and policy development.
Anthropogenic carbon dioxide (CO2) emissions are resulting in increasing absorption of CO2 by the earth‘s oceans, which has led to a decline in ocean pH, a process known as ocean acidification (OA). Evidence suggests that OA may have the potential to affect the distribution and population dynamics of many marine organisms. Early life history processes (e.g. fertilization) and stages (eggs, larvae, juveniles) may be relatively more vulnerable to potential OA impacts, with implications for recruitment in marine populations. The potential impact of OA upon tuna populations has not been investigated, although tuna are key components of pelagic ecosystems and, in the Pacific Ocean, form the basis of one of the largest and most valuable fisheries in the world. This paper reviews current knowledge of potential OA impacts on fish and presents results from a pilot study investigating how OA may affect eggs and larvae of yellowfin tuna, Thunnus albacares. Two separate trials were conducted to test the impact of pCO2 on yellowfin egg stage duration, larval growth and survival. The pCO2 levels tested ranged from present day (~400 uatm) to levels predicted to occur in some areas of the spawning habitat within the next 100 years (<2500 uatm) to 300 years (~<5000 uatm) to much more extreme levels (~10000 uatm). In trial 1, there was evidence for significantly reduced larval survival (at mean pCO2 levels≥4730 uatm) and growth (at mean pCO2 levels≥2108 uatm), while egg hatch time was increased at extreme pCO2 levels≥10000 uatm (⁎intermediate levels were not tested). In trial 2, egg hatch times were increased at mean pCO2 levels≥1573 uatm, but growth was only impacted at higher pCO2 (≥8800 uatm) and there was no relationship with survival. Unstable ambient conditions during trial 2 are likely to have contributed to the difference in results between trials. Despite the technical challenges with these experiments, there is a need for future empirical work which can in turn support modeling-based approaches to assess how OA will affect the ecologically and economically important tropical tuna resources.
Coral reefs and the services they provide are seriously threatened by ocean acidification and climate change impacts like coral bleaching. Here, we present updated global projections for these key threats to coral reefs based on ensembles of IPCC AR5 climate models using the new Representative Concentration Pathway (RCP) experiments. For all tropical reef locations, we project absolute and percentage changes in aragonite saturation state (Ωarag) for the period between 2006 and the onset of annual severe bleaching (thermal stress >8 degree heating weeks); a point at which it is difficult to believe reefs can persist as we know them. Severe annual bleaching is projected to start 10-15 years later at high-latitude reefs than for reefs in low latitudes under RCP8.5. In these 10-15 years, Ωarag keeps declining and thus any benefits for high-latitude reefs of later onset of annual bleaching may be negated by the effects of acidification. There are no long-term refugia from the effects of both acidification and bleaching. Of all reef locations, 90% are projected to experience severe bleaching annually by 2055. Furthermore, 5% declines in calcification are projected for all reef locations by 2034 under RCP8.5, assuming a 15% decline in calcification per unit of Ωarag. Drastic emissions cuts, such as those represented by RCP6.0, result in an average year for the onset of annual severe bleaching that is ~20 years later (2062 vs. 2044). However, global emissions are tracking above the current worst-case scenario devised by the scientific community, as has happened in previous generations of emission scenarios. The projections here for conditions on coral reefs are dire, but provide the most up-to-date assessment of what the changing climate and ocean acidification mean for the persistence of coral reefs.
We quantify forcing and feedbacks across available CMIP5 coupled atmosphere-ocean general circulation models (AOGCMs) by analysing simulations forced by an abrupt quadrupling of atmospheric carbon dioxide concentration. This is the first application of the linear forcing-feedback regression analysis of Gregory et al. (2004) to an ensemble of AOGCMs. The range of equilibrium climate sensitivity is 2.1-4.7 K. Differences in cloud feedbacks continue to be important contributors to this range. Some models show small deviations from a linear dependence of top-of-atmosphere radiative fluxes on global surface temperature change. We show that this phenomenon largely arises from shortwave cloud radiative effects over the ocean and is consistent with independent estimates of forcing using fixed sea-surface temperature methods. We suggest that future research should focus more on understanding transient climate change, including any time-scale dependence of the forcing and/or feedback, rather than on the equilibrium response to large instantaneous forcing. Citation: Andrews, T., J. M. Gregory, M. J. Webb, and K. E. Taylor (2012), Forcing, feedbacks and climate sensitivity in CMIP5 coupled atmosphere-ocean climate models, Geophys. Res. Lett., 39, L09712, doi: 10.1029/2012GL051607.
Despite the growing number of in situ iron fertilization experiments, the efficiency of such fertilization to sequester atmospheric CO2 remains largely unknown. For the first time, a global ocean biogeochemical model has been evaluated against those experiments and then used to estimate the effect of a long-term and large-scale iron addition on atmospheric CO2. The model reproduces the observed timing and amplitude in chlorophyll, the shift in ecosystem composition, and the pCO2 drawdown; it also proves to be of utility in interpreting the observations. However, a full ocean fertilization during 100 years results in a 33 μatm decrease in atmospheric CO2, that is 2 to 3 times smaller than found previously.
Albacore tuna catch data from the summer of 1981 are displayed on concurrent satellite images of sea surface temperature and phytoplankton pigment concentration, from the NOAA-7 Advanced Very High Resolution Radiometer (AVHRR) and the Nimbus-7 Coastal Zone Color Scanner (CZCS), respectively. During 3 week-long periods off California, intense fishing activity and larger catches, indicating aggregations of albacore, were located within pockets of warm, blue oceanic water intruding into the boundary between oceanic and cooler greenish coastal waters. A relatively productive oceanic region, defined by a color front visible in a CZCS image, was the site of albacore aggregation in waters several hundred miles offshore during the first 2 weeks of September 1981.