Size matters: How single-species management can contribute to ecosystem-based fisheries management

In this study we show how substantial gains towards the goals of ecosystem-based fisheries management (EBFM) can be achieved by different single-species management. We show that fishing has much less impact on stocks if fish are caught after they have reached the size (Lopt) where growth rate and cohort biomass are maximum. To demonstrate our point we compare the impact of three fishing scenarios on 9 stocks from the North Sea and the Baltic. Scenario (1) is the current fishing regime, scenario (2) is a new management regime proposed by the European Commission, aiming for maximum sustainable yield obtained from all stocks, and scenario (3) is set so that it achieves the same yield as scenario (2), albeit with fishing on sizes beyond Lopt. Results show that scenarios (2) and (3) are significant improvements compared to current fishing practice. However, scenario (3) consistently shows least impact on the stocks, with seven-fold higher biomass of demersal fishes and an age structure similar to an unfished stock. This allows juveniles and adults to better fulfil their ecological roles, a major step towards the goals of ecosystem-based fisheries management. We give examples where scenario (3) is practiced in successful fisheries. We present a new interpretation of the relative yield per recruit isopleth diagram with indication of a new target area for fisheries operating within the context of EBFM. We present a new expression of the relative biomass per recruit isopleth diagram, which supports our analysis. We conclude that size matters for precautionary and ecosystem-based fisheries management and present a list of additional advantages associated with fishing at Lopt

Eco-Label Conveys Reliable Information on Fish Stock Health to Seafood Consumers

Concerns over fishing impacts on marine populations and ecosystems have intensified the need to improve ocean management. One increasingly popular market-based instrument for ecological stewardship is the use of certification and eco-labeling programs to highlight sustainable fisheries with low environmental impacts. The Marine Stewardship Council (MSC) is the most prominent of these programs. Despite widespread discussions about the rigor of the MSC standards, no comprehensive analysis of the performance of MSC-certified fish stocks has yet been conducted. We compared status and abundance trends of 45 certified stocks with those of 179 uncertified stocks, finding that 74% of certified fisheries were above biomass levels that would produce maximum sustainable yield, compared with only 44% of uncertified fisheries. On average, the biomass of certified stocks increased by 46% over the past 10 years, whereas uncertified fisheries increased by just 9%. As part of the MSC process, fisheries initially go through a confidential pre-assessment process. When certified fisheries are compared with those that decline to pursue full certification after pre-assessment, certified stocks had much lower mean exploitation rates (67% of the rate producing maximum sustainable yield vs. 92% for those declining to pursue certification), allowing for more sustainable harvesting and in many cases biomass rebuilding. From a consumer's point of view this means that MSC-certified seafood is 3–5 times less likely to be subject to harmful fishing than uncertified seafood. Thus, MSC-certification accurately identifies healthy fish stocks and conveys reliable information on stock status to seafood consumers

Time trends of current biomass (total or spawning) relative to biomass levels at the time of MSC assessment for stocks with available information and more than 5 years of certification.

<p>Colors represent current stock status (green to yellow: <i>B</i>><i>B</i>MSY; orange to red: <i>B</i><<i>B</i>MSY) and dots represent most recent year of available information (as per <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043765#pone.0043765.s001" target="_blank">Table S1</a>).</p

Performance of MSC-certified and uncertified fisheries.

<p>Long term trends (1970–2009) of biomass relative to their targets levels (i.e., estimated biomass at which the maximum sustainable yield should be obtained: <i>B</i>_MSY; median ±S.E.). <i>B</i>_MSY is set to 1 (broken line).</p

Sustainability of certified and uncertified seafood.

<p>Current (i.e., most recent year with available information) biomass and exploitation rate for (<b>A</b>) individual certified (<i>n</i> = 45); (<b>B</b>) all uncertified (<i>n</i> = 179); and (<b>C</b>) uncertified stocks that went through pre-assessment and were not recommended for certification (<i>n</i> = 25). Data are scaled relative to <i>B</i>MSY and <i>u</i>MSY or <i>F</i>MSY (the biomass and exploitation rates or fishing mortality rates that produce maximum sustainable yield). Contour colors show probability of occurrence (red indicates the highest probability and blue the lowest). Vertical and horizontal solid lines represent reference points common to all fisheries (<i>B/B</i>MSY = 1 and <i>u/u</i>MSY or <i>F/F</i>MSY = 1). Dotted lined represents <i>B</i> = 1.3<i>B</i>MSY and dashed line <i>B</i> = 0.5<i>B</i>MSY. Footnote: New assessments for some fish stocks were released while this paper was in press, but this figure was not updated to maintain consistency in year of release.</p

" Marine Areas of Responsible Fishing " : A Path Toward Small-Scale Fisheries Co-Management in Costa Rica? Perspectives from Golfo Dulce

International audienceThis chapter analyzes participatory management processes of small-scale fisheries in two Pacific embayments of Costa Rica, a centralized state of Central America where fisheries management is traditionally " top-down " , data deficient, and poorly adapted to local biological and socioeconomic conditions. We provide an historical overview of coastal activities governance and fisheries national context, and describe different participative approaches to small-scale fishery management. The Marine Area of Responsible Fishing (Área Marina de Pesca Responsable, or AMPR), created in 2008, is a management tool developed by the Costa Rican government to effectively involve fishers organizations in small-scale fisheries management. In this paper, we compare participative management initiatives associated with AMPRs in the Golfo Dulce and Golfo de Nicoya (Palito and Tár-coles), and Marine Protected Areas (MPAs) in Cahuita and Marino Ballena National Parks. Based on our analysis, we recommend ten measures to improve the small-scale fisheries co-management process. Among these, five recommendations stand out: (1) increase the participation of artisanal fishers in the development of collective choice rules; (2) allocate costs and benefits of management measures among artisanal fishers; (3) improve local leadership ; (4) improve understanding and transparency of the management process; and (5) formalize and implement strategic fisheries management plans