Nicholas A J Graham

Nicholas A J Graham
James Cook University · ARC Centre of Excellence for Coral Reef Studies

PhD

About

246
Publications
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22,245
Citations

Publications

Publications (246)
Article
Full-text available
Alteration of benthic reef habitat after coral bleaching and mortality induces changes in fish assemblages, with implications for fisheries. Our understanding of climate impacts to coral reef fisheries is largely based on fish abundance and biomass. The rates at which biomass is produced and replenished (productivity and turnover) are also importan...
Article
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The direct and indirect effects of climate change can affect, and are mediated by, changes in animal behaviour. However, we often lack sufficient empirical data to assess how large‐scale disturbances affect the behaviour of individuals, which scales up to influence communities. Here, we investigate these patterns by focusing on the foraging behavio...
Article
Full-text available
Human impact increasingly alters global ecosystems, often reducing biodiversity and disrupting the provision of essential ecosystem services to humanity. Therefore, preserving ecosystem functioning is a critical challenge of the twenty-first century. Coral reefs are declining worldwide due to the pervasive effects of climate change and intensive fi...
Article
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Significance The world produces enough food to nourish the global population, but inequitable distribution of food means many people remain at risk for undernutrition. Attainment of Sustainable Development Goal 2 relies on greater attention to distribution processes that match food qualities with dietary deficiencies. We explore this in the context...
Article
Mobile consumers are key vectors of cross-ecosystem nutrients, yet have experienced population declines which threaten their ability to fill this role. Despite their importance and vulnerability, there is little information on how consumer biodiversity, in addition to biomass, influences the magnitude of nutrient subsidies. Here, we show that both...
Article
Effective solutions to the ongoing “coral reef crisis” will remain limited until the underlying drivers of coral reef degradation are better understood. Here, we conduct a global-scale study of how four key metrics of ecosystem states and processes on coral reefs (top predator presence, reef fish biomass, trait diversity, and parrotfish scraping po...
Article
Macroalgae‐dominated reefs are a prominent habitat in tropical seascapes that support a diversity of fishes, including fishery target species. To what extent, then, do macroalgal habitats contribute to small‐scale tropical reef fisheries? To address this question we: (1) Quantified the macroalgae‐associated fish component in catches from 133 small‐...
Article
Climate‐induced coral bleaching events are a leading threat to coral reef ecosystems and can result in coral–macroalgal regime shifts that are difficult to reverse. It is unclear how different factors causally influence regime shift or recovery trajectories after a bleaching event. Here, we use structural causal modeling (SCM) and its application o...
Article
Understanding the underlying drivers of biodiversity is essential for conservation planning of large, connected seascapes. We tested how patterns in α and β components of species and functional diversity of coral reef fish (214, species, 23 families) varied along the extensive Chagos-Lakshadweep oceanic ridge (the largest chain of mid-oceanic atoll...
Preprint
Tropical reefs provide livelihood and food security to millions of people. However, tropical reefs are entering new configurations requiring management strategies to incorporate process-oriented measures such as biomass production to determine their dynamics and resilience. We proposed a new framework, comprising three management strategies based o...
Article
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Wild-caught fish are a bioavailable source of nutritious food that, if managed strategically , could enhance diet quality for billions of people. However, optimising nutrient production from the sea has not been a priority, hindering development of nutrition-sensitive policies. With fisheries management increasingly effective at rebuilding stocks a...
Article
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Climate change is transforming coral reefs, threatening supply of essential dietary micronutrients from small-scale fisheries to tropical coastal communities. Yet the nutritional value of reef fisheries and climate impacts on micronutrient availability remain unclear, hindering efforts to sustain food and nutrition security. Here, we measure nutrie...
Article
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In a time of unprecedented ecological change, understanding natural biophysical relationships between reef resilience and physical drivers is of increasing importance. This study evaluates how wave forcing structures coral reef benthic community composition and recovery trajectories after the major 2015/2016 bleaching event in the remote Chagos Arc...
Article
There is an increasing recognition that, although the climate change and biodiversity crises are fundamentally connected, they have been primarily addressed independently and a more integrated global approach is essential to tackle these two global challenges. Nature‐based Solutions (NbS) are hailed as a pathway for promoting synergies between the...
Article
Bioindicators are useful for determining nutrient regimes in marine environments, but their ability to evaluate corals reefs in different ecological states is poorly understood. The precision, availability and congruency of eight potential bioindicators (brown macroalgae, green macroalgae, turf algae, cyanobacteria, soft corals, zoanthids, sponges,...
Article
Coral reefs are harbingers of environmental change. In this issue of One Earth, Eddy et al. analyze long-term declines in reef condition and fish catches. Here, we highlight how policies that secure coral reefs as local food systems can safeguard diverse, nutrient rich diets and support vulnerable social-ecological systems.
Article
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Replacement of coral by macroalgae in post-disturbance reefs, also called a "coral-macroalgal regime shift", is increasing in response to climate-driven ocean warming. Such ecosystem change is known to impact planktonic and benthic reef microbial communities but few studies have examined the effect on animal microbiota. In order to understand the c...
Article
Full-text available
Fish are rich in bioavailable micronutrients, such as zinc and iron, deficiencies of which are a global food security concern.¹,² Global marine fisheries yields are threatened by climate change and overfishing,³,⁴ yet understanding of how these stressors affect the nutrients available from fisheries is lacking.⁵,⁶ Here, using global assessments of...
Article
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By improving resource quality, cross-ecosystem nutrient subsidies may boost demographic rates of consumers in recipient ecosystems, which in turn can affect population and community dynamics. However, empirical studies on how nutrient subsidies simultaneously affect multiple demographic rates are lacking, in part because humans have disrupted the m...
Article
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Scleractinian corals are engineers on coral reefs that provide both structural complexity as habitat and sustenance for other reef-associated organisms via the release of organic and inorganic matter. However, coral reefs are facing multiple pressures from climate change and other stressors, which can result in mass coral bleaching and mortality ev...
Article
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Understanding ecosystem service change necessitates an understanding of the social and ecological dimensions of ecosystem services and how they contribute to the well‐being of different people. These empirical research gaps persist across the tropics and in coastal environments, posing a challenge for small island states that depend on ecosystem se...
Article
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Protected areas are the flagship management tools to secure biodiversity from anthropo-genic impacts. However, the extent to which adjacent areas with distinct protection levels host different species numbers and compositions remains uncertain. Here, using reef fishes, European alpine plants, and North American birds, we show that the composition o...
Article
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Biological invasions pose a threat to nearly every ecosystem worldwide.1,2 Although eradication programs can successfully eliminate invasive species and enhance native biodiversity, especially on islands,3 the effects of eradication on cross-ecosystem processes are unknown. On islands where rats were never introduced, seabirds transfer nutrients fr...
Article
1. Extensive and dense macroalgal fields can compromise the ecosystem function of habitat mosaics on reefs owing to their limiting effect on patch connectivity. Macroalgae can maintain and increase their dominance with effective self-reinforcing feedback mechanisms. For example, macroalgae can form dense beds, supressing coral settlement and grazin...
Article
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Understanding species’ roles in food webs requires an accurate assessment of their trophic niche. However, it is challenging to delineate potential trophic interactions across an ecosystem, and a paucity of empirical information often leads to inconsistent definitions of trophic guilds based on expert opinion, especially when applied to hyperdivers...
Article
• Reef fish biomass is increasingly recognized as a key indicator of fishery and biodiversity status linked to ecosystem integrity on coral reefs, and yet the evaluation of appropriate baselines for biomass, and what drives variation in potential baselines, is sparse. • Variability in reef fishable biomass was assessed to test for the existence of...
Article
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To cope effectively with the impacts of climate change, people will need to change existing practices or behaviours within existing social–ecological systems (adaptation) or enact more fundamental changes that can alter dominant social–ecological relationships and create new systems or futures (transformation). Here we use multilevel network modell...
Article
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Positive relationships between biodiversity and ecosystem functioning (BEF) highlight the importance of conserving biodiversity to maintain key ecosystem functions and associated services. Although natural systems are rapidly losing biodiversity due to numerous human-caused stressors, our understanding of how multiple stressors influence BEF relati...
Article
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Canopy-forming macroalgae can construct extensive meadow habitats in tropical seascapes occupied by fishes that span a diversity of taxa, life-history stages and ecological roles. Our synthesis assessed whether these tropical macroalgal habitats have unique fish assemblages, provide fish nurseries and support local fisheries. We also applied a meta...
Article
Coral reefs host hundreds of thousands of animal species that are increasingly threatened by anthropogenic disturbances. These animals host microbial communities at their surface, playing crucial roles for their fitness. However, the diversity of such microbiomes is mostly described in a few coral species and still poorly defined in other invertebr...
Article
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Social–ecological systems (SES) exhibit complex cause‐and‐effect relationships. Capturing, interpreting, and responding to signals that indicate changes in ecosystems is key for sustainable management in SES. Breaks in this signal–response chain, when feedbacks are missing, will allow change to continue until a point when abrupt ecological surprise...
Article
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Coral reef ecosystems are among the first to fundamentally change in structure due to climate change, which leads to questioning of whether decades of knowledge regarding reef management is still applicable. Here we assess ecological responses to no-take marine reserves over two decades, spanning a major climate-driven coral bleaching event. Pre-bl...
Article
The worldwide decline of coral reefs necessitates targeting management solutions that can sustain reefs and the livelihoods of the people who depend on them. However, little is known about the context in which different reef management tools can help to achieve multiple social and ecological goals. Because of nonlinearities in the likelihood of ach...
Article
Full-text available
Rapid and unprecedented ecological change threatens the functioning and stability of ecosystems. On coral reefs, global climate change and local stressors are reducing and reorganizing habitat-forming corals and associated species, with largely unknown implications for critical ecosystem functions such as herbivory. Herbivory mediates coral–algal c...
Article
Full-text available
Canopy-forming macroalgae can construct extensive meadow habitats in tropical seascapes occupied by fishes that span a diversity of taxa, life history stages and ecological roles. Our synthesis assessed whether these tropical macroalgal habitats have unique fish assemblages, provide fish nurseries, and support local fisheries. We also applied a met...
Article
Full-text available
Trait-based ecology strives to better understand how species, through their bio-ecological traits, respond to environmental changes, and influence ecosystem functioning. Identifying which traits are most responsive to environmental changes can provide insight for understanding community structuring and developing sustainable management practices. H...
Article
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Climate change can alter conditions that sustain food production and availability, with cascading consequences for food security and global economies. Here, we evaluate the vulnerability of societies to the simultaneous impacts of climate change on agriculture and marine fisheries at a global scale. Under a “business-as-usual” emission scenario, ~9...
Article
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Nutrient content analyses of marine finfish and current fisheries landings show that fish have the potential to substantially contribute to global food and nutrition security by alleviating micronutrient deficiencies in regions where they are prevalent.
Article
Global climate change is altering community composition across many ecosystems due to nonrandom species turnover, typically characterized by the loss of specialist species and increasing similarity of biological communities across spatial scales. As anthropogenic disturbances continue to alter species composition globally, there is a growing need t...
Article
Tropical reef systems are transitioning to a new era in which the interval between recurrent bouts of coral bleaching is too short for a full recovery of mature assemblages. We analyzed bleaching records at 100 globally distributed reef locations from 1980 to 2016. The median return time between pairs of severe bleaching events has diminished stead...
Article
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Coral community composition varies considerably due to both environmental conditions and disturbance histories. However, the extent to which coral composition influences associated fish assemblages remains largely unknown. Here an ecological trait-based ordination analysis was used to compare functional richness (range of unique trait combinations)...
Article
Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for on...
Article
Additional information for «Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes » concerning the Methods and Results section. The Life History Traits (LHT) categorization is described in details, and additional references using those LHT are given. In addition, details concerning the taxonomic and functio...
Article
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High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might performunique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, pote...
Article
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Ongoing declines in the structure and function of the world's coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the 'outliers'-places where...
Article
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State indicators, e.g., mean size and trophic level of the fish assemblage, can provide important insights into the effects of fishing on ecosystems and the resource potential of the fishery. On coral reefs, few studies have examined the relative effects of fishing and other drivers, such as habitat, on these indicators. In light of habitat heterog...
Article
Fish biomass is a primary driver of coral reef ecosystem services and has high sensitivity to human disturbances, particularly fishing. Estimates of fish biomass, their spatial distribution, and recovery potential are important for evaluating reef status and crucial for setting management targets. Here we modeled fish biomass estimates across all r...
Data
Summary statistics of the nls models. (XLSX)
Data
High resolution map of the western Indian Ocean for (a) modeled biomass based on the empirical relationship established in Fig 1., (b) the estimated time to recover biomass to a mean estimated sustainability level (450 kg/ha). Recovery rates are based on studies of biomass recovery in fully protected fisheries closures studied over a 20-year period...
Data
High resolution map of the Western Indian Ocean for (a) the estimated time to recover biomass to a mean estimated sustainability level (600 kg/ha), and (b) the estimated time to recover biomass to the estimated conservation target of 1150 kg/ha. Recovery rates are based on studies of biomass recovery in fully protected fisheries closures studied ov...
Data
High resolution map derived from algorithm identifying and prioritizing the most depleted fish biomass for small closures and adjacent spillover reefs until all reefs with biomass <450 kg/ha are classified. (EPS)
Data
High resolution maps of Marzone maximum probability priority selections for 50% sustainability, 20% conservation, and 30% unmanaged where to time to recovery was the cost and minimized if (a) countries collaborated to reach these goals, and (b) there was no collaboration between countries. (EPS)
Data
Classification of reefs by their management categories used for estimating biomass. (JPG)
Data
A model selection table showing the 95% confidence set of models. (DOCX)
Article
Corals and coral-associated species are highly vulnerable to the emerging effects of global climate change. The widespread degradation of coral reefs, which will be accelerated by climate change, jeopardizes the goods and services that tropical nations derive from reef ecosystems. However, climate change impacts to reef social–ecological systems ca...
Article
Coral reef fisheries are of great importance both economically and for food security, but many reefs are showing evidence of overfishing, with significant ecosystem-level consequences for reef condition. In response, ecological indicators have been developed to assess the state of reef fisheries and their broader ecosystem-level impacts. To date, u...
Article
Additional figures and tables to complement «Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes ». This is a set of figures first to complement the Methods such as the accumulation curves of species as well as conceptual figures for the vulnerability framework used. Additional figures are also provided c...