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Mean discard rates and 95% confidence bound (CI) for different fishing gears from Pérez Roda et al. , 2019 (Table B1).
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Mobile bottom contact gear such as trawls is widely considered to have the highest environmental impact of commonly used fishing gears, with concern about impact on benthic communities, bycatch, and carbon footprint frequently highlighted as much higher than other forms of fishing. As a result, the use of such gears has been banned or severely rest...
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Context 1
... Food and Agriculture Organization (FAO) databases on country-specific landings, Pérez Roda et al. (2019) estimated the discard rate and magnitude for the period 2010-2014 for global marine capture fisheries using fishery-specific discard rates derived from direct observations and global gearspecific discard rates. Discard rates for trawl fisheries and selected other gear types are shown in Table 1 . Table 1 shows that the dominant determinant of discard rate is whether the fishing occurs on the bottom or surface or Table 2. ...Context 2
... rates for trawl fisheries and selected other gear types are shown in Table 1 . Table 1 shows that the dominant determinant of discard rate is whether the fishing occurs on the bottom or surface or Table 2. The average, minimum, and maximum amount of fuel used to capture one MT (litres per MT) of fish for different gear types and the amount of carbon released per kilogramme (Kg) of fish wet weight landed (Kg CO 2 per kg landed). ...Context 3
... Food and Agriculture Organization (FAO) databases on country-specific landings, Pérez Roda et al. (2019) estimated the discard rate and magnitude for the period 2010-2014 for global marine capture fisheries using fishery-specific discard rates derived from direct observations and global gearspecific discard rates. Discard rates for trawl fisheries and selected other gear types are shown in Table 1 . Table 1 shows that the dominant determinant of discard rate is whether the fishing occurs on the bottom or surface or Table 2. ...Context 4
... rates for trawl fisheries and selected other gear types are shown in Table 1 . Table 1 shows that the dominant determinant of discard rate is whether the fishing occurs on the bottom or surface or Table 2. The average, minimum, and maximum amount of fuel used to capture one MT (litres per MT) of fish for different gear types and the amount of carbon released per kilogramme (Kg) of fish wet weight landed (Kg CO 2 per kg landed). ...Context 5
... Food and Agriculture Organization (FAO) databases on country-specific landings, Pérez Roda et al. (2019) estimated the discard rate and magnitude for the period 2010-2014 for global marine capture fisheries using fishery-specific discard rates derived from direct observations and global gearspecific discard rates. Discard rates for trawl fisheries and selected other gear types are shown in Table 1 . Table 1 shows that the dominant determinant of discard rate is whether the fishing occurs on the bottom or surface or Table 2. ...Context 6
... rates for trawl fisheries and selected other gear types are shown in Table 1 . Table 1 shows that the dominant determinant of discard rate is whether the fishing occurs on the bottom or surface or Table 2. The average, minimum, and maximum amount of fuel used to capture one MT (litres per MT) of fish for different gear types and the amount of carbon released per kilogramme (Kg) of fish wet weight landed (Kg CO 2 per kg landed). ...Similar publications
Although South Africa accounts for half of the alternative meat market for the African continent, there remains a lack of information about consumer demand for plant-based and lab-cultured meat and its market potential domestically. This study reports the results of a nationwide survey of 649 South African consumers who completed a choice experimen...
Citations
... The environmental impact of fuel consumption in the fishing industry has become a critical concern due to increasing consumer awareness and efforts to combat climate change. Bottom trawling, a widely used fishing method, is particularly scrutinized for its high fuel use, greenhouse gas (GHG) emissions, and potential disturbance of seabed sediments, which may release additional carbon into the ocean (Sala et al., 2021;Hilborn et al., 2023). While bottom trawls contribute to approximately 26% of global marine catches and support millions of livelihoods (Steadman et al., 2021), they are also recognized as one of the most fuel-intensive fishing methods due to the drag and friction caused by heavy gear components (Tyedmers, 2001;Suuronen et al., 2012;Sala et al., 2022). ...
Demersal trawling is among the most energy-intensive fishing practices worldwide, primarily due to the drag and frictional force caused by their heavy components. This study aimed to estimate fuel use intensity (litres of fuel per kilogram of landed catch) and associated carbon dioxide emissions of Turkish trawl vessels, most of which still operate using traditional trawl nets equipped with heavy otter boards and lead ground gear, increasing towing
resistance and consequently fuel consumption. Data from 129 commercial fishing trips conducted by 13 trawl vessels between 2021 and 2022 were analysed using Generalized Linear Models (GLMs). Overall, to catch one kg of landed marine product, the trawl vessels consumed approximately a median value of 1.22 litres of fuel and emitted 3.21 kg of CO2 for the given period. Vessel length, engine power and the target species group were the main factors affecting the fuel use intensity. The results obtained from the study provide critical insights for implementing effective management measures to decarbonize fisheries, offering practical recommendations for decision makers. Expanding the dataset to encompass a broad range of vessels, regions, and fishing seasons would further enhance the generalizability and applicability across different fisheries.
... These transformations align with broader maritime trends, including shifting shipping routes, heightened geopolitical tensions over marine resources, and the growing need for improved ocean governance. While technological advancements offer potential solutions, achieving sustainability requires contextspecific strategies that align with both ecological and socio-economic realities (Hilborn et al., 2023). ...
The fishing industry faces mounting challenges due to economic instability, technological advancements, and environmental changes, raising concerns about its long-term sustainability. This study, What's Next for Fishermen? Examining Future Maritime Trends and Industry Sustainability, explores the evolving maritime trends and future outlook of the fishing community in La Libertad, Negros Oriental, Philippines. It aims to assess fishermen's socioeconomic conditions, identify their technological aspirations, and determine key factors shaping marine capture fisheries. A descriptive research design was employed, involving 254 respondents from six coastal barangays: Pisong, Martilo, North Poblacion, South Poblacion, Cantupa, and San Jose. Data were collected through structured surveys and analyzed using statistical tools. Results indicate that most fishermen are male, aged 46-60, married, and supporting households of 1-5 members, with monthly earnings below ₱9,520 and low educational attainment. Technological preferences highlight a shift toward modernization, with Fiber Glass Boats, Spin Cast Fishing Reels, and Fish Finders emerging as the most sought-after equipment. Fishermen anticipate improvements in fishery management systems and resource recovery but recognize the necessity of investing in new fishing grounds due to shifting fish populations. The study underscores the critical role of government support in providing access to modern fishing technologies, enhancing management systems, and ensuring economic stability. Findings offer valuable insights for policymakers in developing targeted interventions that address industry challenges, promote sustainable fishing practices, and enhance the resilience of coastal communities. Strengthening collaboration between fishermen, local authorities, and stakeholders is vital in navigating future maritime trends and securing the long-term viability of marine capture fisheries.
... The true nature and scale of this impact is not well understood, especially in Namibia, and varies across ecosystems, trawling methods, bottom types and target species (e.g. Hilborn et al. 2023). Some papers in this field suggested the global trawl industry was potentially responsible for more carbon release than the global airline industry as calculations showed the industry trawled 1.3% of the global ocean (4.9 million km 2 annually), resulting in the release of 1.47 Pg of aqueous CO 2 emissions, owing to the higher carbon metabolism which occurs in sediments within a year of trawling (Sala et al. 2021). ...
... Some papers in this field suggested the global trawl industry was potentially responsible for more carbon release than the global airline industry as calculations showed the industry trawled 1.3% of the global ocean (4.9 million km 2 annually), resulting in the release of 1.47 Pg of aqueous CO 2 emissions, owing to the higher carbon metabolism which occurs in sediments within a year of trawling (Sala et al. 2021). However, these values have been questioned and may be substantially overestimated due to miscalculations in some of the carbon transfer rates , Hilborn et al., 2023. The carbon component of benthic marine sediments in Namibia is very high but calculating transfer rates is complicated by high levels of anoxic water on the seabed, so we discuss these in more detail below. ...
... A previous study reported an interesting point that there had been a shift in the abundant species of shrimp, with increasing biomass of the demersal fish and more density of larger-sized shrimp in the middle area of Java Sea two years after the ban of trawl (arad) fishing gear had been imposed (Tirtadanu and Suprapto 2017). Another study showed that bottom trawl and dredge fishing have been sustained, where habitats for benthic sedimentary remain in good condition with a well-managed fishing pressure (Hilborn et al. 2023). ...
Pribadi TDK, Yusfiandayani R, Simbolon D, Patanda M, Caesario R, Sayidina EJ, Violita SR. 2024. A comparison of diversity and catch composition of mini trawl (arad) and lift net (bagan) in Cilincing, Jakarta Bay, Indonesia. Biodiversitas 25: 265-277. Arad is a traditional fishing gear that is still popular and widely used in Indonesia, including in Cilincing, the bay in the northern part of Jakarta. Even though the Indonesian government has prohibited this fishing gear, the discarded fishing gear is still utilized by many fishers due to its effective result in getting a large volume of fish caught. A study on the diversity and catch composition of arad (trawl) and bagan (lift net) fishing gear was conducted between January and June 2024 in Cilincing waters to represent active and passive fishing gear. Samples of fish caught from both fishing gears were observed directly, while interviews with the fishers were conducted to get further information on their view. The study showed that in comparison to bagan, arad caught more species, including reef fish. Both fishing gear caught fin-fish and non-finfish (mollusk, crustacean, jellyfish) in different proportions. The data showed that arad caught more species (28) compared to bagan (18). Arad caught mostly demersal fish (57.14%), while bagan mostly caught pelagic fish (53.33%). The value of Total Length (TL) of fish caught by both fishing gears was mostly under the Length of First of Maturity (LM). Referring to the list issued by IUCN, most of the species caught by arad and bagan were in the Least Concern status of conservation, and neither CITES nor the Indonesian Ministry of Environment and Forestry has issued any information regarding the population status.
... Galapagos and its surrounding waters is no exception to this, as reports from both legal and illegal fishing activities show Bonaccorso et al., 2021;Jacquet et al., 2008;Schiller et al., 2014). Although there may be some examples of sustainable longlining, sustainability is strongly linked to effective management (Hilborn et al., 2023). Galapagos fisheries management, past and present, does not instill confidence that a longline fishery would be well managed, adequately funded and effectively monitored. ...
... Consequently, some countries have banned or strictly limited the use of trawls, and other regions are considering similar restrictions [63]. Comparative studies on trawl fisheries and other food production systems indicate that well-managed trawl fisheries can sustainably maintain fish stocks with potentially lower environmental impacts than certain land-based protein sources, such as beef [64]. Effective management practices-such as spatial protections, species-specific safeguards, and gear modifications-can reduce the environmental footprint of trawling. ...
Shrimp trawl fishery is of significant importance in Saudi Arabia’s marine capture fishery sector. Al Qunfudhah and Jizan are the only ports along the southern Saudi Arabian coast of the Red Sea dedicated to shrimp fishing. This study evaluates the catch per unit effort (CPUE) of targeted shrimp species along with the associated retained bycatch and discard ratios across these two trawling locations. Using daily catch data from commercial shrimp trawlers specific to each port’s vessel type, this research provides the first comprehensive analysis of CPUE dynamics and fishing practices in these fishing grounds. The CPUE of target shrimps exhibited a wide range (0.01 kg h−1 to 13.08 kg h−1) with an overall mean of 1.37 ± 0.143 kg h−1. Penaeus semisulcatus emerged as the predominant species (mean CPUE: 3.77 ± 0.28 kg h−1), followed by Metapenaeus monoceros (mean CPUE: 0.1 ± 0.02 kg h−1). Significant differences in CPUE were observed among species, including P. semisulcatus, Penaeus hathor, and Penaeus pulchricaudatus, although CPUE differences between the two fishing grounds were minor, likely due to their proximity and similar environmental conditions. The bycatch analysis identified a total of 72 species across 28 families, with significant variation in the relative ratios. Sepiidae species constituted 31.8% of the total bycatch, followed by Portunidae species (24.8%). Discard patterns also varied, with Gerres oyena being the most commonly discarded species (mean discard ratio: 11.37% ± 1.89%), followed by Equulites klunzingeri (mean discard ratio: 8.76% ± 2.00%). While CPUE differences between Al Qunfudhah and Jizan were modest, this study highlights the need for expanded spatial and temporal coverage to enhance future analyses. These findings underscore the importance of integrated data for a comprehensive understanding of fishing effort and bycatch dynamics, supporting sustainable fisheries management in the Red Sea. By addressing bycatch and discard practices, this research contributes to efforts to mitigate ecological impacts and promote sustainable resource use in Saudi Arabia’s fisheries sector.
... These fisheries land 26% of global marine fisheries catches. Hilborn et al. (2023) conducted a comprehensive study of the environmental impacts of trawl fisheries, comparing them to other fishing methods with respect to impacts on sustainability of target species, impacts on the seafloor, bycatch and discards and carbon footprint. Carbon footprint was standardised on kilograms (kg) of CO2 produced per kg of processed product from life cycle analyses for foods ranging from corn (lowest at 0.10) to beef (19.2) (Hilborn et al., 2023, p. Table 3). ...
Fisheries and aquaculture produce highly nutritious foods that are generally of high value, and often targeted at export markets. Slow to recognise the threats from climate change, research by sectoral experts and greater attention to aquatic systems (freshwater and marine) by the IPCC rapidly improved understanding of likely productivity changes from climate change. Diverse approaches to adaptation are revealed by reviews of today’s adaptation practices, the most prominent pathways promised by technological fixes and emerging more comprehensive socio-technical systems approaches. The major challenges brought by climate change are going to exacerbate the ongoing dilemmas of how adaptation will affect small-scale fisheries and aquaculture and the large-scale enterprises, and which people will be advantaged or displaced in the adaptation processes.
... However, we note that the term "midwater" may be misleading, considering that some midwater trawls do not fish only in midwater. For instance, the pollock fishery in Alaska uses midwater gear, but is estimated to be in contact with the seabed roughly half the time (Hilborn et al. 2023;Stratton and Wilson 2023). Dredges and seines are also described here, considering that these gears have impacts on the seabed similar to those of bottom trawls. ...
... Dredges and seines, in particular, can produce effects similar to those of bottom trawls, and some of these fishing gears may be classified in the same category as bottom trawls. For instance, Hilborn et al. (2023) considered "shellfish dredges" as bottom trawls, and Danish seines (see the description below) are classified as bottom trawls under European legislation. ...
... Similar to the finding in Amoroso et al. (2018), eight European regions had the worst seabed status: Adriatic Sea, waters west of Spain, Skagerrak and Kattegat, Tyrrhenian Sea, western Baltic Sea, North Sea, Aegean Sea and Irish Sea. The Adriatic Sea had by far the poorest seabed status (Pitcher et al. 2022;Hilborn et al. 2023). ...
Download pdf (free): http://www.oceancare.org/trawlsupremacy
--- Trawling is a type of fishing characterized by the active towing of nets by a moving boat. Trawl nets vary greatly in size and shape, and they target a wide variety of species, including bottom-dwelling fish, crustaceans and molluscs, pelagic and semi-pelagic schooling fish, and deep-water fauna. In this report, we provide a general overview on towed gear, but we focus more specifically on bottom trawling: the towing of nets along the seabed. Bottom trawling has become a cornerstone of global food supplies, accounting for more than one quarter of global fishery landings. In 2016, this equated to over 30 million tonnes of seafood. In several European and African countries, half of fishery landings come from bottom trawling. Bottom trawling, however, has long been known to be detrimental to marine life. It was regarded as a destructive fishing method since the early 14th century, and was often vocally opposed by communities of fishers who saw it as a threat to marine resources and their own livelihoods. The introduction of steam and diesel engines (in the 1830s and 1930s, respectively) marked the modern era of trawling. Engine-powered trawling increased rapidly during the 1960s, and by the 1980s large fleets of trawlers were combing the global oceans. Today’s bottom trawlers can operate virtually anywhere, from shallow inland channels and rivers to deep offshore waters. Countless scientific studies, encompassing decades of fishery research, have documented the harmful nature of bottom trawling, with substantial cumulative evidence of damage to marine species and ecosystems. Bottom trawling reduces the biomass, diversity and complexity of benthic communities, and the action of trawl gear on the seabed causes dramatic mechanical and chemical alterations, compromising the seabed’s functionality and productivity. In addition to the target species, most types of trawl gear take unwanted species, such as threatened elasmobranchs, sea turtles, seabirds and marine mammals. Apart from these biological impacts, recent studies indicate that bottom trawling has a considerable carbon footprint, with high direct and indirect greenhouse gas emissions contributing to climate disruption. Information on the harmful effects of bottom trawling has resulted in public and institutional awareness of environmental damage, and in restrictions that have sometimes included complete bans. Trawling is often prohibited in the most coastal and shallow waters. However, regulations and enforcement levels vary greatly across areas, and environmental protection measures are often ineffective—to the point that the intensity of bottom trawling can be higher inside than outside some Marine Protected Areas. In this report, we review the evidence of how bottom trawling affects marine life and human life. We also summarize some of the primary management approaches that could help mitigate the harmful effects of trawling—consistent with international commitments to protect the marine environment. We conclude that the amount of seafood produced by bottom trawling can no longer justify or excuse the pervasive damage caused to marine ecosystems and communities of small-scale fishers, and we advocate the use of less destructive fishing gear, combined with the creation of areas protected from harmful fishing practices, and more sustainable strategies to “feed the world”.
... Further, trawling disturbs seabed sediments, leading to CO2 release and potential impacts on climate change (Atwood et al. 2024). Although bottom trawling is likely to have a high carbon footprint on average, compared to most other animal source food production systems, such as livestock or fed aquaculture, is has a lower environmental impact in many other aspects, such as water used, antibiotic use and nutrient release (Hilborn et al. 2023). When technical gear and spatial management measures | ICES SCIENTIFIC REPORTS 6:78 | ICES are implemented, these environmental impacts would likely become lower overall than livestock or fed aquaculture forms of food production (Hilborn et al. 2023). ...
... Although bottom trawling is likely to have a high carbon footprint on average, compared to most other animal source food production systems, such as livestock or fed aquaculture, is has a lower environmental impact in many other aspects, such as water used, antibiotic use and nutrient release (Hilborn et al. 2023). When technical gear and spatial management measures | ICES SCIENTIFIC REPORTS 6:78 | ICES are implemented, these environmental impacts would likely become lower overall than livestock or fed aquaculture forms of food production (Hilborn et al. 2023). ...
ICES workshop on status of vulnerable marine ecosystems in the NEAFC Regulatory Area for 5-year review (WKVMESTAT) was formed as part of the formal ICES advisory process in response to requests from the North-East Atlantic Fisheries Commission (NEAFC). These requests were for advice on relevant scientific issues for the NEAFC five year review of the effectiveness of the NEAFC Recommendation 19:2014 on the protection of vulnerable marine ecosystems (VME) in the NEAFC Regulatory Area.
WKVMESTAT reviewed and summarised ICES advice to NEAFC on VME and identified two issues to be considered by NEAFC and ICES.
To address changes to scientific understanding on evidence for VME and for Significant Adverse Impacts (SAI) of bottom fishing, WKVMESTAT reviewed relevant policy instruments, technical guidance and supporting documents at the global as well as regional levels. In relation to VME, the Workshop focused on definitions/descriptions/criteria, the use of the term VME in different fora, how the science to identify VMEs has been reflected in these instruments, and other scientific processes that may relate to VMEs but that utilize different terminologies. Regarding significant adverse impacts (SAI) of bottom fishing activities on VMEs the Workshop focused on the assessment of those impacts, as well as on the use of thresholds related to VME encounters.
The use of the term VME in the United Nations General Assembly (UNGA) Sustainable Fisheries Resolution of 2003 (58/14) was a major impetus for deep-sea research to provide the evidence base to support policy decisions on VMEs. Much of the early work was focused on identification of VME indicator taxa and documenting their presence in areas beyond national jurisdiction. More recently, there have been significant relevant scientific developments in the information available to decision-makers to meet the more recent UNGA resolutions (i.e., 71/123, 77/118, and 78/68) and those of other international policies (e.g., Convention on Biological Diversity, UN Sustainable Development Goals). WKVMESTAT identified eleven areas of research where a body of relevant science has been published. For each, this report provides a description of the research subject, the relevance to VME policy, and give some insights into the future direction of that research.
Recommendation 19:2014 divides NEAFC’s regulatory areas into three categories: bottom fishing areas, areas closed for protection of VMEs and restricted bottom fishing areas. Previous ICES advice, addressing the effectiveness of the VME closures and the regulation of fisheries in the protected bottom fishing areas in protecting VMEs, support the conclusion that the measures have been effective in protecting VMEs. For the bottom fishing areas WKVMESTAT does not have the evidence to assess the effectiveness of NEAFC Recommendation in protecting VMEs.
WKVMESTAT also reviewed the list of “VME indicators” in Annex 5 to the NEAFC recommendation and provide suggestions for additions and changes to the list.
... Regarding fishing methods, trawling and dredging are associated with catches of demersal fish, crustaceans and molluscs. They allow for bigger catches compared to and higher safety for fishermen (Alverson, 1994); however, they are not a selective method, therefore there is a higher probability of bycatches than with other fishing methods (Hilborn et al., 2023). From an ecological view, these methods can impact the ecosystem in the race-to-fish, causing high mortality of benthos and, consequently, on species relying on the benthos (Thrush et al., 2016). ...
The port of Genoa is among the busiest ports in Italy, and it plays a significant role in the Mediterranean landscape of fisheries and maritime economy. The European Union aims for a more sustainable and circular economy. Following European directives, countries need to develop maritime management plans. A summary and review of the available literature and information on the fishing industry in the specific location of the port of Genoa, Italy, is provided in this paper to understand better the current situation and potentially research solutions for a more circular and green economy of the city. The Italian government has developed a management programme for fisheries on the national level. However, marine resources appear to be overexploited in Italian waters, and the goal of reaching a maximum sustainable yield has yet to be achieved. The impact of fisheries and maritime transportation has been studied over the years. On the other hand, the relationship between the port and the city must be considered. The Italian government recognizes the need for an integrated management plan that revolves around the ecological, economic and social aspects of the problem. Further research is needed to understand better the relationship between the economy, citizens, and port.
