scholarly journals ICES advisory framework 1977–2012: from Fmax to precautionary approach and beyond

2013 ◽  
Vol 71 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Hans Lassen ◽  
Ciaran Kelly ◽  
Michael Sissenwine
Keyword(s):  
Maximum Sustainable Yield ◽  
Growth Potential ◽  
Total Allowable Catch ◽  
Precautionary Approach ◽  
Fish Stocks ◽  
North East ◽  
The North ◽  
Spawning Stock ◽  
Harvest Control Rule ◽  
Annual Total

Abstract Lassen, H., Kelly, C., and Sissenwine, M. 2014. ICES advisory framework 1977–2012: from Fmax to precautionary approach and beyond. – ICES Journal of Marine Science, 71: 166–172. The International Council for the Exploration of the Sea (ICES) provides fishery advice in the context of international agreements and addressing the policy and legal needs of ICES Member Countries. This advice is often formulated for an annual total allowable catch based on decisions made by the North East Atlantic Fisheries Commission (NEAFC) during the first half of the 1970s. Although this early advice was initially focused on the best usage of the growth potential of the fish stocks, the collapse of important pelagic stocks in the late 1960s and the early 1970s suggested that the biological advice should include serious considerations of the spawning–stock biomass (SSB). ICES responded with a new advisory framework in 1976. Over the next 30 years, the advisory framework evolved, with increasing emphasis placed on ensuring SSB to avoid impairing recruitment. The Plan of Implementation of the 2002 UN World Summit on Sustainable Development (WSSD) calls for the restoration and maintenance of fish stocks to levels than can produce the fisheries that provide maximum sustainable yield (MSY). In 2009, ICES revised its advisory framework now formulated as a harvest control rule aimed at achieving MSY.

The “Lost Mackerel” of the North East Atlantic—The Flawed System of Trilateral and Bilateral Decision-making

2013 ◽  
Vol 28 (2) ◽  
pp. 343-373 ◽  
Author(s):  
Peter Ørebech
Keyword(s):  
Decision Making ◽  
East Atlantic ◽  
Total Allowable Catch ◽  
Fish Stocks ◽  
Atlantic Mackerel ◽  
North East ◽  
The North ◽  
Quota Allocation ◽  
Decision Making Processes ◽  
The Right

Abstract The North East Atlantic mackerel is moving westward and northward. How to integrate new coastal states whose Exclusive Economic Zone is invaded by mackerel into existing decision-making processes? The 1982 Law of the Sea Convention, the 1995 Straddling Fish Stocks Agreement, the 1980 North East Atlantic Fisheries Convention, and bilateral and trilateral agreements between “relevant coastal states” fail to provide rules for present decision-makers to incorporate newcomers. The present harvesting states are sovereign with regard to admitting or refusing newcomers. This article argues for a stricter obligation on coastal states to acknowledge the right of new harvesting nations to access decision-making processes for estimating total allowable catch and allocating quotas. Equitable distribution can occur if quota allocation is subject to principles that are less discretionary than the present ones. One solution is to estimate the ratio of biomass related to the share of coastal states in the distribution of eggs, larvae and fishable stock, and allocate a quota to each coastal and high seas fishing state accordingly.

Estimating uncertainty of data limited stock assessments

2016 ◽  
Vol 74 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Alexandros Kokkalis ◽  
Anne Maria Eikeset ◽  
Uffe H. Thygesen ◽  
Petur Steingrund ◽  
Ken H. Andersen
Keyword(s):  
Stock Assessment ◽  
Assessment Method ◽  
Fish Stocks ◽  
Stock Status ◽  
North East ◽  
The North ◽  
Stock Biomass ◽  
Uncertainty Estimates ◽  
Stock Assessments ◽  
Spawning Stock

Many methods exist to assess the fishing status of data-limited stocks; however, little is known about the accuracy or the uncertainty of such assessments. Here we evaluate a new size-based data-limited stock assessment method by applying it to well-assessed, data-rich fish stocks treated as data-limited. Particular emphasis is put on providing uncertainty estimates of the data-limited assessment. We assess four cod stocks in the North-East Atlantic and compare our estimates of stock status (F/Fmsy) with the official assessments. The estimated stock status of all four cod stocks followed the established stock assessments remarkably well and the official assessments fell well within the uncertainty bounds. The estimation of spawning stock biomass followed the same trends as the official assessment, but not the same levels. We conclude that the data-limited assessment method can be used for stock assessment and that the uncertainty estimates are reliable. Further work is needed to quantify the spawning biomass of the stock.

Prey switching by killer whales in the north-east Atlantic: observational evidence and experimental insights

2013 ◽  
Vol 94 (6) ◽  
pp. 1357-1365 ◽  
Author(s):  
Dag Vongraven ◽  
Anna Bisther
Keyword(s):  
Killer Whale ◽  
Large Population ◽  
Tooth Wear ◽  
Killer Whales ◽  
Prey Switching ◽  
Photo Identification ◽  
North East ◽  
The North ◽  
Spawning Stock

Studies in the Pacific have identified distinct killer whale ecotypes that are either specialized mammal- or fish-eaters. The different types have developed hunting strategies that would suggest specialization could be more advantageous than generalism. However, it has been suggested, based on long-term dietary markers of tooth wear and stable isotope values, that lineages in the North Atlantic are generalist, but with individual variation in the proportion of prey types consumed. Here, we present the results of ten years of observational and photo-identification data of a population of killer whales that follows the Norwegian spring-spawning stock of Atlantic herring. Although the whales were predominantly observed while feeding upon herring, one pod of herring-eating whales was also observed interacting with seals. This supports the hypothesis based on the long-term markers, of a degree of specialization, with a small number of groups persistently feeding upon mammals, but switching between herring and seals. We further investigated this prey switching by conducting playbacks of herring-eating killer whale sounds to harbour seals at haul-out sites on the herring spawning grounds. We recorded changes in behaviour consistent with an anti-predator response, suggesting the seals perceived the herring-eating killer whales as a potential predatory threat and had not habituated to their calls. This could be due to the risk of herring-eating killer whales switching to mammalian prey, or the difficulty of discriminating between killer whale pods due to the large population size and number of killer whale call dialects in this population, or a combination of both.

scholarly journals Evaluating management strategies to implement the recovery plan for Iberian hake (Merluccius merluccius); the impact of censored catch information

2009 ◽  
Vol 67 (2) ◽  
pp. 258-269 ◽  
Author(s):  
Ernesto Jardim ◽  
Santiago Cerviño ◽  
Manuela Azevedo
Keyword(s):  
Management Strategies ◽  
Maximum Sustainable Yield ◽  
Sustainable Yield ◽  
Fishing Mortality ◽  
Merluccius Merluccius ◽  
Total Allowable Catch ◽  
Recovery Plan ◽  
Stock Biomass ◽  
Spawning Stock ◽  
The Impact

Abstract Jardim, E., Cerviño, S., and Azevedo, M. 2010. Evaluating management strategies to implement the recovery plan for Iberian hake (Merluccius merluccius); the impact of censored catch information. – ICES Journal of Marine Science, 67: 258–269. Iberian hake assessment revealed an increase in fishing mortality (F) despite enforcement of a recovery plan. Recent landings exceeded the total allowable catch and discarding rates were high. Alternative management strategies based on F control were evaluated with respect to the probability of recovering spawning-stock biomass (SSB), expected profits, and robustness to uncertainty on catch information and stock dynamics. Results showed that the use of censored catch data, i.e. excluding the Gulf of Cádiz or discards, may lead to inappropriate conclusions. Reducing fishing mortality was necessary for SSB to recover. An Fmax strategy with discard reduction showed the highest probability of rebuilding SSB and led the fishery to sustainable exploitation, with an expected %SPR of 30–40% in 2025, mean individual weight in the landings of 450 g in 2015, and yield increasing by >20%. Because of uncertainty in the estimates of maximum sustainable yield, management strategies based on FMSY were least robust, but all strategies were robust to alternative stock–recruit models.

scholarly journals Linking the performance of a data-limited empirical catch rule to life-history traits

2020 ◽  
Vol 77 (5) ◽  
pp. 1914-1926
Author(s):  
Simon H Fischer ◽  
José A A De Oliveira ◽  
Laurence T Kell
Keyword(s):  
Time Series ◽  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Growth Parameter ◽  
Reference Points ◽  
Total Allowable Catch ◽  
Fish Stocks ◽  
Wide Range ◽  
Spawning Stock

Abstract Worldwide, the majorities of fish stocks are data-limited and lack fully quantitative stock assessments. Within ICES, such data-limited stocks are currently managed by setting total allowable catch without the use of target reference points. To ensure that such advice is precautionary, we used management strategy evaluation to evaluate an empirical rule that bases catch advice on recent catches, information from a biomass survey index, catch length frequencies, and MSY reference point proxies. Twenty-nine fish stocks were simulated covering a wide range of life histories. The performance of the rule varied substantially between stocks, and the risk of breaching limit reference points was inversely correlated to the von Bertalanffy growth parameter k. Stocks with k>0.32 year−1 had a high probability of stock collapse. A time series cluster analysis revealed four types of dynamics, i.e. groups with similar terminal spawning stock biomass (collapsed, BMSY, 2BMSY, 3BMSY). It was shown that a single generic catch rule cannot be applied across all life histories, and management should instead be linked to life-history traits, and in particular, the nature of the time series of stock metrics. The lessons learnt can help future work to shape scientific research into data-limited fisheries management and to ensure that fisheries are MSY compliant and precautionary.

Recent Changes in the Central and Southern North Sea Herring Stocks

1985 ◽  
Vol 42 (S1) ◽  
pp. s192-s206 ◽  
Author(s):  
A. C. Burd
Keyword(s):  
North Sea ◽  
Maximum Yield ◽  
Total Allowable Catch ◽  
Underlying Assumption ◽  
Southern North Sea ◽  
The North ◽  
Management Procedure ◽  
Stock Biomass ◽  
Spawning Stock ◽  
The North Sea

Since 1980 there has been a sudden recovery of recruitment to the central and southern North Sea herring stocks (Bank and Downs, respectively). In contrast, recruitment to the northern North Sea has continued at a low level and spawning stock biomass has even declined since 1979. These events underline the independence of the substocks in the North Sea, each of which has reacted differently to the cessation of the directed herring fishery in the North Sea since 1977. A precondition to the reopening of a herring fishery in the North Sea was that the severely depleted spawning stock biomass should have recovered to 800 000 t, the underlying assumption being that all components would respond in a similar manner and that a reopening of the whole North Sea would be possible. This has not happened and it may well be that management of the North Sea as a single unit is not a viable management procedure. The paper examines the historic changes in sizes of the Bank and Downs stocks, with particular emphasis on the most recent period. Evidence of density-dependent growth change is considered together with the recent data on fecundity and larval herring production. It is concluded that if the separate stocks are to be managed individually for maximum yield, then global North Sea regulations such as a total allowable catch and size regulation are inappropriate. Regulations must also take into consideration the seasonal distributions of the stocks. Indeed, this would lead, in particular, to more restrictive and specific regulation of the industrial fisheries.

scholarly journals Measuring the net biological impact of fisheries enhancement: pink salmon hatcheries can increase yield, but with apparent costs to wild populations

2017 ◽  
Vol 74 (8) ◽  
pp. 1233-1242 ◽  
Author(s):  
Ricardo O. Amoroso ◽  
Michael D. Tillotson ◽  
Ray Hilborn
Keyword(s):  
Large Scale ◽  
Juvenile Fish ◽  
Pink Salmon ◽  
Major Change ◽  
Maximum Sustainable Yield ◽  
Oncorhynchus Gorbuscha ◽  
Precautionary Approach ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
The North ◽  
Hatchery Program

Hatchery production of juvenile fish for release into the wild has been practiced for well over a century in an effort to increase the number of salmon available to harvest. In this study, we evaluate the net impact of the largest such program in North America, the hatchery program for pink salmon (Oncorhynchus gorbuscha) in Prince William Sound (PWS), Alaska. At the same time the hatchery program was increasing in output, there was a major change in productivity in the North Pacific so that throughout Alaska pink salmon increased dramatically in abundance between the 1970s and the 2000s. Using other regions of Alaska as reference sites, we estimate that the PWS hatchery program has increased the total catch by an average of 17 million fish, of which 8 million have been allocated to pay hatchery operating expenses. We estimate that the maximum sustainable yield (MSY) of wild spawning fish in PWS has increased slightly (28%), while in regions of Alaska without pink salmon hatchery programs the MSY has tripled. Our results support the use of a precautionary approach to future large-scale stock enhancement efforts.

scholarly journals Changing recruitment capacity in global fish stocks

2015 ◽  
Vol 113 (1) ◽  
pp. 134-139 ◽  
Author(s):  
Gregory L. Britten ◽  
Michael Dowd ◽  
Boris Worm
Keyword(s):  
Environmental Changes ◽  
Meta Analysis ◽  
Chlorophyll Concentration ◽  
Fish Stock ◽  
Productive Capacity ◽  
Large Variability ◽  
Fish Stocks ◽  
Large Marine Ecosystems ◽  
The North ◽  
Spawning Stock

Marine fish and invertebrates are shifting their regional and global distributions in response to climate change, but it is unclear whether their productivity is being affected as well. Here we tested for time-varying trends in biological productivity parameters across 262 fish stocks of 127 species in 39 large marine ecosystems and high-seas areas (hereafter LMEs). This global meta-analysis revealed widespread changes in the relationship between spawning stock size and the production of juvenile offspring (recruitment), suggesting fundamental biological change in fish stock productivity at early life stages. Across regions, we estimate that average recruitment capacity has declined at a rate approximately equal to 3% of the historical maximum per decade. However, we observed large variability among stocks and regions; for example, highly negative trends in the North Atlantic contrast with more neutral patterns in the North Pacific. The extent of biological change in each LME was significantly related to observed changes in phytoplankton chlorophyll concentration and the intensity of historical overfishing in that ecosystem. We conclude that both environmental changes and chronic overfishing have already affected the productive capacity of many stocks at the recruitment stage of the life cycle. These results provide a baseline for ecosystem-based fisheries management and may help adjust expectations for future food production from the oceans.

scholarly journals Fishing for MSY: using “pretty good yield” ranges without impairing recruitment

2016 ◽  
Vol 74 (2) ◽  
pp. 525-534 ◽  
Author(s):  
Anna Rindorf ◽  
Massimiliano Cardinale ◽  
Samuel Shephard ◽  
José A. A. De Oliveira ◽  
Einar Hjorleifsson ◽  
...  
Keyword(s):  
Good Yield ◽  
Maximum Sustainable Yield ◽  
Fishing Mortality ◽  
Fish Yield ◽  
Fish Stocks ◽  
Northern European ◽  
Stock Biomass ◽  
Spawning Stock ◽  
Average Catch

Pretty good yield (PGY) is a sustainable fish yield corresponding to obtaining no less than a specified large percentage of the maximum sustainable yield (MSY). We investigated 19 European fish stocks to test the hypothesis that the 95% PGY yield range is inherently precautionary with respect to impairing recruitment. An FMSY range was calculated for each stock as the range of fishing mortalities (F) that lead to an average catch of at least 95% of MSY in long-term simulations. Further, a precautionary reference point for each stock (FP.05) was defined as the F resulting in a 5% probability of the spawning-stock biomass falling below an agreed biomass limit below which recruitment is impaired (Blim) in long-term simulations. For the majority of the stocks analysed, the upper bound of the FMSY range exceeded the estimated FP.05. However, larger fish species had higher precautionary limits to fishing mortality, and species with larger asymptotic length were less likely to have FMSY ranges impairing recruitment. Our study shows that fishing at FMSY generally is precautionary with respect to impairing recruitment for highly exploited teleost species in northern European waters, whereas the upper part of the range providing 95% of MSY is not necessarily precautionary for small- and medium-sized teleosts.

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