Global status of groundfish stocks (original) (raw)
Related papers
The Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 requires Regional Fishery Management Councils to set annual catch limits for all stocks or stock complexes in Federal fishery management plans beginning in 2011. Most species listed in the Pacific Coast Groundfish Fishery Management Plan have not been assessed, in large part due to data limitations. Estimates of sustainable yield for many these species were previously based on undocumented, ad-hoc analyses. We present estimates of sustainable yield for 50 of these stocks using two recently developed models designed to inform management of data-poor stocks. These models rely on recently reconstructed time series of historical catch for west-coast groundfish species and species-specific information related to stock productivity. For this set of data-poor stocks, recent landings statistics reflect shifts in the relative importance of certain species to west-coast fisheries (e.g. increased catches of nearshore and slope rockfish species relative to shelf species), largely due to recent regulatory actions. We provide estimates of overfishing limits (OFLs) for each of the 50 stocks along with comparisons to recent catch levels. Our results suggest that status quo harvest levels range from light exploitation of some stocks to potential overfishing of others. This information could help inform decisions regarding prioritization of future stock assessments for unassessed species. OFLs are expressed as probability distributions, reflecting our uncertainty in model parameters. We select median values as point estimates of OFL, as this statistic is most consistent with National Standard 1 guidelines.
In Search of Optimal Harvest Rates for West Coast Groundfish
North American Journal of Fisheries Management, 2002
In this paper, I explore how patterns of compensatory mortality, as assessed through stock-recruitment relationships, may influence optimal harvest rates and relative yields for several West Coast groundfish stocks. To do this, I revisited Clark's (1991) groundfish life history model and maximin (i.e., maximize the minimum) yield approach to evaluate target harvest rates for five stocks (Dover sole Microstomus pacificus, lingcod Ophiodon elongatus, sablefish Anoplopoma fimbria, Pacific hake Merluccius productus, and widow rockfish Sebastes entomelas) using recent estimates of fishery and life history parameters and stock-recruitment data. I found that a spawningstock-per-recruit target of roughly 35% of its unfished amount would be reasonable for these stocks if Clark's assumed stock-recruitment parameters are representative and the policy goal is a maximin yield. In contrast, use of estimated stock-recruitment parameters suggested more conservative percentages of the unfished spawning stock per recruit and more conservative harvest rate targets for most stocks. A key implication of this work is that Clark's groundfish life history model is sensitive to the stock-recruitment shape parameters. As a result, these parameters should be estimated where possible or imputed using results from meta-analyses. Overall, a conservation target of roughly 35% of the unfished spawning stock per recruit is very likely too low for lingcod, sablefish, and widow rockfish stocks under current environmental conditions, but it may be adequate for Dover sole and Pacific hake stocks.
A preliminary global assessment of the status of exploited marine fish and invertebrate populations
2018
An assessment of the status of 1320 fish and invertebrate populations (or 'stocks') of 484 species exploited by fisheries in 232 Marine Ecoregions (MEs) overlapping with the Exclusive Economic Zones (EEZs) of 218 countries and their overseas territories was performed using the CMSY method applied to annual catches (1950-2014) reconstructed by the Sea Around Us, with some emphasis on the 64 MEs overlapping with the EEZs of countries where OCEANA operates. The main finding was that a large majority of the assessed populations (85%) had biomass below that associated with Maximum Sustainable Yield (BMSY), 38% were outside of safe biological limits (B < 0.5 BMSY) and 7% were collapsed (B < 0.2 BMSY). Thus, these populations would be expected to generate higher sustainable catches if allowed to rebuild. A preliminary conservative estimate gives the foregone catch for the examined stocks as 20 million tonnes (24%), when catches in 2014 are compared with 90% of MSY level catches. The 90% reduction accounts for the fact that predator-prey interactions make it impossible to achieve MSY for all stocks simultaneously. This study examined only stocks identified to species level. If the above percentage is scaled up to the total catch, this would amount to a preliminary estimate of about 26 million tonnes of foregone catch. As expected, cases with unreliable catch statistics generated questionable results and high uncertainties. In particular, the CMSY method, when applied to catch statistics from countries that 'manufactured' high catches in recent decades, suggested lower declines in biomass than likely occurred. This implies that the results presented herein are conservative, i.e., do not exaggerate declining trends in biomass. This study is preliminary in that informative priors could be provided only for fish and invertebrate populations in the waters of countries conducting systematic fisheries research on their major exploited populations. A plan is briefly presented on how this shortcoming will be mitigated in the second year of this project, which will also see the development of new features on the website of the Sea Around Us, allowing for the biomass estimates and other data from our stock assessments to be downloaded and/or the assessments to be rerun with different prior estimates. In the meantime, this report presents summaries of the status of some of the major stocks in the countries where OCEANA operates, while summaries (in form of PDFs) for all 2711 stocks may be found at www.seaaroundus.org.under under the respective MEs or EEZs. MATERIALS AND METHODS Reconstructed catches vs official catches The catch time series data used for the present study are based on FAO data, corrected and complemented through a procedure called 'catch reconstruction', documented in Zeller et al. (2007), Lam et al. (2016), Palomares et al. (2016) and Zeller et al. (2016). The actual reconstructions were largely performed on a per-country (or overseas territory) basis, with over 200 papers (Fisheries Centre Working Papers, chapters in Fisheries Centre Research Reports, book chapters and articles in peer-reviewed journals) documenting the time series reconstructions in 273 EEZs or parts thereof (see Pauly and Zeller 2016b). Herein, the catch of industrial, artisanal, subsistence and recreational fisheries of each country or territory was presented, based on catch and related data from FAO or the fisheries agency of the country or territory in question, complemented with data from other sectors as required to obtain a complete time series, from 1950-2010 (now updated to 2014) of catches by the above-mentioned sectors including estimates of illegal and previously unreported catches (see, e.g.
Pacific Coast Groundfish Management: Evolution and Prospects
SUMMARY Although federal management of Pacific coast groundfish strongly resembles previous state and international management programs, the current fishery management plan (FMP) contains i mportant new elements as well. The groundfish FMP adopts state f ishing gear regulations, but seeks more coastwide uniformity. As in previous internat agreements, foreign fishing is limited to Pacific whiting and mackerel (with minimum incidental catch of other groundfish), prohibited in areas sensitive to U.S. interests. Development domestic rockfish and joint venture fishing has changed the f and has challenged the management system to devise approaches onal jack and is of major shery to new problems. Annual harvest quotas or "guide1 ines" were established for several commercial species. These are based on "optimum yield" estimates derived from biological stock assessments. is its flexible procedure for modifying the annual harvest guidelines in response to new information a...
Improving estimates of the state of global fisheries depends on better data
Fish and Fisheries, 2021
Assessments of the global state of fish populations play a critical role in tracking the implementation of the United Nations Sustainable Development Goals. While we have reliable estimates of stock status for fish populations accounting for approximately half of recent global catch, our knowledge of the state of the majority of the word's 'unassessed' fish stocks remains highly uncertain. Numerous publications have produced estimates of the global status of these unassessed fisheries, but limited quantity and quality of data along with methodological differences have produced counterintuitive and conflicting results. Here, we show that despite numerous efforts, our understanding of the status of global fish stocks remains incomplete, even when new sources of broadly available data are added. Estimates of fish populations based primarily on catch histories alone frequently performed roughly as well as a random guess. Obtaining accurate estimates of stock status for the world's exploited fish populations depends on prioritizing the collection of high-priority data around the globe, rather than the development of new modeling methods alone.
2015
This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/.
Northeast Fisheries Science Center Reference Documents This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/.