The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Rashid U Sumaila - One of the best experts on this subject based on the ideXlab platform.
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end Overfishing and increase the resilience of the ocean to climate change
Frontiers in Marine Science, 2020Co-Authors: Rashid U Sumaila, Travis C TaiAbstract:Abstract Marine fish stocks and the ecosystems they inhabit are in decline in many parts of our ocean, including in some European waters, because of Overfishing and the ecosystem effect of fishing in general. Simultaneously, climate change is disrupting the physics, chemistry and ecology of the ocean, with significant consequences on the life it holds. While the positive effects of mitigating climate change on the ocean and marine life are currently being documented, papers that examine how ending Overfishing could increase ocean resilience to climate change are less common. The goal of this paper is to review the current literature and conduct an analysis that demonstrate that ending Overfishing and reducing other negative ecosystem effects of fishing would make fish stocks and marine ecosystems more resilient to climate change. Our findings suggest that fish and fish stocks are no different from other living organisms and are more likely to survive external pressures when healthy.
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how to make progress in disciplining Overfishing subsidies
Ices Journal of Marine Science, 2013Co-Authors: Rashid U SumailaAbstract:The World Trade Organization (WTO) has been working for more than seven years now to discipline Overfishing subsidies, as mandated by the global community, without success. I argue that this failure is partly because WTO negotiators aim for an all-inclusive deal, i.e. negotiations are conducted as a “single undertaking”, whereby results must be achieved in all areas. Negotiators are required to broker an all-inclusive deal for all maritime WTO member countries and for all fisheries, whether domestic or international; small or large scale; developing or developed country fisheries. It is argued here that this commitment to a “single undertaking” does not align the incentive to remove subsidies with national interests, and therefore needs to be changed by splitting the world’s fisheries into domestic and international fisheries. In this way, the battle for eliminating Overfishing subsidies for some stocks would shift to home countries, and for others this would still rest with the international community. This split, it is argued, would align the incentives and improve the chances of eliminating Overfishing subsidies.
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can cooperative management of tuna fisheries in the western pacific solve the growth Overfishing problem
Strategic Behavior and the Environment, 2013Co-Authors: Megan Bailey, Rashid U Sumaila, Steven J D MartellAbstract:Can Cooperative Management of Tuna Fisheries in the Western Pacific Solve the Growth Overfishing Problem?
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Overfishing call to split fisheries at home and abroad
Nature, 2012Co-Authors: Rashid U SumailaAbstract:I agree that “no one should doubt that our seas need protection” (Nature 480, 151; 2011) and that establishing marine protected areas alone will not do the job (Nature 480, 14–15; 2011). A combination of measures is needed, including the elimination of Overfishing subsidies. These incentives were introduced when fisheries seemed inexhaustible, but they inflate profitability and drive fishing beyond economic or sustainable levels.
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malthusian Overfishing in pulau banggi
Marine Policy, 2007Co-Authors: Louise S L Teh, Rashid U SumailaAbstract:Abstract We assess, based on fisheries and interview data collected on-site, whether Malthusian Overfishing is occurring in Pulau Banggi, Sabah. Fisheries resources in Pulau Banggi have been perceived to be declining over the past 20 years, and characteristics of Malthusian Overfishing are evident, although not at a magnitude comparable with other more heavily exploited artisanal fisheries in the Philippines. It appears that Pulau Banggi's reef fisheries are at an early stage of Malthusian Overfishing, and this is therefore a critical time for addressing and mitigating drivers of Overfishing to prevent inevitable and further decline of Pulau Banggi's reef fisheries.
Masami Fujiwara - One of the best experts on this subject based on the ideXlab platform.
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assessment of a small scale fishery lane snapper lutjanus synagris using a length metric method
PLOS ONE, 2021Co-Authors: Liliana Sierra Castillo, Masami FujiwaraAbstract:Small-scale fisheries are hard to assess because of the limited availability of data. Therefore, a method requiring easy-to-obtain catch-data is important for the assessment and management of small-scale fisheries. The objective of this study was to assess the effect of fishing gear selectivity on a length-based metric method proposed by Froese by estimating three indicators using catch-data from Lane Snapper (Lutjanus synagris) collected in Honduras. These indicators are (1) the percentage of mature individuals in the catch, (2) the percentage of fish within the range of estimated optimal lengths to be captured, and (3) the percentage of fish larger than the optimal length. These indicators determine the level of Overfishing. The indicators were estimated separately for catch-data corresponding to gill nets, and each indicator was estimated with and without selectivity correction. Selectivity and mesh sizes of the fishing gear had a major impact on the estimation of indicators 1 and 2. As for indicator 3, it consistently showed a high level of exploitation. The three estimated indicators suggested that the Lane Snapper fishery in Honduras is experiencing Overfishing. Overall, the method appears to be promising for the assessment of small-scale fisheries, but it should be used cautiously.
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assessment of a small scale fishery lane snapper lutjanus synagris using a length metric method
bioRxiv, 2020Co-Authors: Liliana Sierra Castillo, Masami FujiwaraAbstract:ABSTRACT Small-scale fisheries are hard to assess because of the limited availability of data. Therefore, a method requiring easy-to-obtain catch-data is important for the assessment and management of small-scale fisheries. The objectives of this study were to assess the effect of fishing gear selectivity on a length-based metric method proposed by Froese by estimating three indicators using catch-data from Lane Snapper (Lutjanus synagris) collected in Honduras. These indicators are (1) the percentage of mature individuals in the catch, (2) the percentage of fish within the range of estimated optimal lengths to be captured and (3) the percentage of fish larger than the optimal length. These indicators determine the level of Overfishing. The indicators were estimated separately for catchdata corresponding to gillnets, and each indicator was estimated with and without selectivity correction. Selectivity and mesh sizes of the fishing gear had a major impact in the estimation of indicators 1 and 2. As for indicator 3, it consistently showed a high level of exploitation. The three estimated indicators suggested that the Lane Snapper fishery in Honduras, is experiencing Overfishing. Overall, the method proposed by Froese appears to be promising for the assessment of small-scale fisheries, but it should be used cautiously.
Alexander S. Flecker - One of the best experts on this subject based on the ideXlab platform.
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extremely long distance seed dispersal by an overfished amazonian frugivore
Proceedings of The Royal Society B: Biological Sciences, 2011Co-Authors: Jill T Anderson, Tim Nuttle, Joe Saldana Rojas, Thomas H Pendergast, Alexander S. FleckerAbstract:Throughout Amazonia, Overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter...
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extremely long distance seed dispersal by an overfished amazonian frugivore
Proceedings of The Royal Society B: Biological Sciences, 2011Co-Authors: Jill T Anderson, Tim Nuttle, Joe Saldana Rojas, Thomas H Pendergast, Alexander S. FleckerAbstract:Throughout Amazonia, Overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum . During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma , and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337–552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700–2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but Overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.
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Fish extinctions alter nutrient recycling in tropical freshwaters
Proceedings of the National Academy of Sciences, 2007Co-Authors: P. B. Mcintyre, L. E. Jones, Alexander S. Flecker, Michael J VanniAbstract:There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communities could affect nutrient recycling. Here, we use extensive field data on nutrient recycling rates and population sizes of fish species in a Neotropical river and Lake Tanganyika, Africa, to evaluate the effects of simulated extinctions on nutrient recycling. In both of these species-rich ecosystems, recycling was dominated by relatively few species, but contributions of individual species differed between nitrogen and phosphorus. Alternative extinction scenarios produced widely divergent patterns. Loss of the species targeted by fishermen led to faster declines in nutrient recycling than extinctions in order of rarity, body size, or trophic position. However, when surviving species were allowed to increase after extinctions, these compensatory responses had strong moderating effects even after losing many species. Our results underscore the complexity of predicting the consequences of extinctions from species-rich animal communities. Nevertheless, the importance of exploited species in nutrient recycling suggests that Overfishing could have particularly detrimental effects on ecosystem functioning.
Rainer Froese - One of the best experts on this subject based on the ideXlab platform.
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progress towards ending Overfishing in the northeast atlantic
Marine Policy, 2021Co-Authors: Rainer Froese, Athanassios C. Tsikliras, Giuseppe Scarcella, Didier GascuelAbstract:Abstract The reformed Common Fisheries Policy of the EU, in force since 2014, stipulates that Overfishing by the fleets of its member states has to end latest in the year 2020. This study examines exploitation and status of 119 stocks fished by 20 countries in the Northeast Atlantic. In the year 2018, about 40% of the stocks were still subject to Overfishing (F > Fmsy), about 34% of the stocks were outside safe biological limits (B
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Progress towards ending Overfishing in the Northeast Atlantic
Marine Policy, 2020Co-Authors: Rainer Froese, Giuseppe Scarcella, Athanassios Tsikliras, Didier GascuelAbstract:The reformed Common Fisheries Policy of the EU, in force since 2014, stipulates that Overfishing by the fleets of its member states has to end latest in the year 2020. This study examines exploitation and status of 119 stocks fished by 20 countries in the Northeast Atlantic. In the year 2018, about 40% of the stocks were still subject to Overfishing (F > Fmsy), about 34% of the stocks were outside safe biological limits (B < Bpa) and about 68% of the stocks were too small to produce maximum sustainable yields (B < Bmsy). Reduction in the number of overfished stocks has stalled, possible because of an agreement between the European Commission (EC) and the International Council for the Exploration of the Seas (ICES), its advisory body for total allowed catches (TACs), wherein the EC requests ICES to give TAC advice leading to Overfishing for many stocks. Scientific advice is often overruled or ignored by politicians/fisheries ministers, whose main objective is to get us much quota as possible for their country. As a result, of the TACs set for 2020, about 46% exceeded scientific advice, suggesting that the goal of ending Overfishing in 2020 will not be met.
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progress towards ending Overfishing in the northeast atlantic
GEOMAR Kiel Germany 9 pp., 2019Co-Authors: Rainer Froese, Athanassios C. Tsikliras, Giuseppe Scarcella, Didier GascuelAbstract:The reformed Common Fisheries Policy of the EU, in force since 2014, stipulates that Overfishing by the fleets of its member states has to end latest in the year 2020. This study examines exploitation and status of 119 stocks fished by 20 countries in the Northeast Atlantic. In the year 2018, about 40% of the stocks were still subject to Overfishing (F > Fmsy), about 34% of the stocks were outside safe biological limits (B < Bpa) and about 68% of the stocks were too depleted to produce maximum sustainable yields (B < Bmsy). Reduction in the number of overfished stocks has stalled, possible because of an agreement between the European Commission (EC) and the International Council for the Exploration of the Seas (ICES), its advisory body for total allowed catches (TACs), wherein the EC requests ICES to give TAC advice leading to Overfishing for many stocks. As a result, it is unlikely that Overfishing will end in the Northeast Atlantic in 2020.
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Keep it simple: Three indicators to deal with Overfishing
Fish and Fisheries, 2004Co-Authors: Rainer FroeseAbstract:Three simple fisheries indicators are presented: (i) percentage of mature fish in catch, with 100%, as target; (ii) percent of specimens with optimum length in catch, with 100% as target; and (iii) percentage of 'mega-spawners' in catch, with 0% as target, and 30-40% as representative of reasonable stock structure if no upper size limit exists. Application of these indicators to stocks of Gadus morhua, Sardinella aurita and Epinephelus aeneus demonstrate their usefulness. It is argued that such simple indicators have the potential to allow more stakeholders such as fishers, fish dealers, supermarket managers, consumers and politicians to participate in fisheries management and eventually hold and reverse the global pattern of convenience Overfishing, which is defined here as deliberate Overfishing sanctioned by official bodies who find it more convenient to risk eventual collapse of fish stocks than to risk social and political conflicts.
Fabio Pranovi - One of the best experts on this subject based on the ideXlab platform.
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comparative production of fisheries yields and ecosystem Overfishing in african large marine ecosystems
Environmental development, 2020Co-Authors: Jason S. Link, Fabio Pranovi, Reg Watson, Simone LibralatoAbstract:Marine capture fisheries in African Large Marine Ecosystems (LMEs) are important from economic, cultural, social, and food provision perspectives. These African fisheries have a long history of high exploitation in the context of data-limited situations. There is a growing, global movement (both in terms of management requirements and scientific efforts) to develop measures of ecosystem Overfishing (EOF) that detect Overfishing of an entire ecosystem using readily available data and based on widely repeatable patterns. These EOF indicators extend the thinking beyond single stock Overfishing to an entire ecosystem and are largely based on well-established trophic theory. Moreover, they need to be germane for data limited situations, easily interpretable, and simple to calculate. Here we introduce and present the results of several of these indicators—the Ryther index, Fogarty index, and Friedland index—as well as indices based on cumulative biomass-Trophic Level curve parameters for eight African LMEs. Significantly, all these EOF indicators also have thresholds beyond which EOF is indicated, particularly when coupled with other evidence. These thresholds were applied to the African LME EOF indicators to determine the degree to which EOF may be occurring. Five out of eight African LMEs exhibited symptoms of EOF, one with significant EOF, with at least one LME still currently experiencing EOF, and three more that may be close to EOF thresholds. One LME exhibited evidence of recovering trends. Additionally, EOF indicators detected changes in the LMEs five-ten years prior to major impacts that would be identified by piecing together fishing impacts on a stock-by-stock basis. We conclude that if EOF is detected, at the very least these relative simple measures should be monitored and means to mitigate total fishing pressure in an ecosystem should be explored.
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Ecosystem Overfishing in the ocean
PLoS ONE, 2008Co-Authors: Marta Coll, Sergi Tudela, Simone Libralato, Isabel Palomera, Fabio PranoviAbstract:Fisheries catches represent a net export of mass and energy that can no longer be used by trophic levels higher than those fished. Thus, exploitation implies a depletion of secondary production of higher trophic levels (here the production of mass and energy by herbivores and carnivores in the ecosystem) due to the removal of prey. The depletion of secondary production due to the export of biomass and energy through catches was recently formulated as a proxy for evaluating the ecosystem impacts of fishing-i.e., the level of ecosystem Overfishing. Here we evaluate the historical and current risk of ecosystem Overfishing at a global scale by quantifying the depletion of secondary production using the best available fisheries and ecological data (i.e., catch and primary production). Our results highlight an increasing trend in the number of unsustainable fisheries (i.e., an increase in the risk of ecosystem Overfishing) from the 1950s to the 2000s, and illustrate the worldwide geographic expansion of Overfishing. These results enable to assess when and where fishing became unsustainable at the ecosystem level. At present, total catch per capita from Large Marine Ecosystems is at least twice the value estimated to ensure fishing at moderate sustainable levels.
