Meta-analysis of fishery stock assessments

Tuna fish market
Photo credit: Olaf Jensen

Data from fisheries represent a tremendous opportunity to learn about the dynamics of populations, communities, and ecosystems as well as fisheries management (what works and what doesn’t). Raw catch data, unfortunately, can be misleading. Stock assessments, however, are often quite informative as they combine numerous sources of information to estimate the current and historical stock size and harvest rate. In collaboration with colleagues at Dalhousie University, the University of Washington, and several other universities and government agencies throughout the world, we are building a global database of stock assessments. The RAM Legacy database homepage is here

The database currently contains information from assessments of approximately 350 fish and invertebrate stocks from around the world, including many stocks in Europe, North America, New Zealand, South Africa, Argentina, and Australia. Analysis of these data suggest that the status of fisheries differs widely among regions, with some areas, such as the West Coast of the U.S., appearing to have turned a corner after controlling overfishing. Other regions, such as the Eastern Bering Sea and New Zealand have so far managed to avoid widespread overfishing in the first place. Many parts of the North Atlantic continue to struggle with overfishing and recovery of depleted stocks.

We’ve recently received funding from New Jersey Sea Grant to use this database to improve our understanding of stock-recruit relationships (the relationship between the number of spawning adults and the resulting number of young fish or recruits) for data-poor fish species. By borrowing information from the large number of stocks with spawning stock size and recruitment time series, we can set reasonable bounds on the likely value of stock-recruit parameters for poorly known species or stocks. This can improve stock assessments for data-poor species and ultimately lead to better management. More info

Related publications:

Thorson, J.T., Cope, J.M., Branch, T.A., and O.P. Jensen. (in press). Spawning biomass reference points for exploited marine fishes, incorporating taxonomic and body size information. Canadian Journal of Fisheries and Aquatic Sciences. PDF

Thorson, J.T., Branch, T.A., and O.P. Jensen. 2012. Using model-based inference to evaluate global fisheries status from landings, location and life history data. Canadian Journal of Fisheries and Aquatic Sciences. 69:645-655 PDF

Essington, T.E., Melnychuk, M.C., Branch, T.A.*, Heppell, S.S.*, Jensen, O.P.*, Link, J.S.*, Martell, S.J.D.*, Parma, A.M.*, Pope, J.G.*, Smith, A.D.M.* 2012. Catch shares, fisheries and ecological stewardship: a comparative analysis of resource responses to a rights-based policy instrument.  Conservation Letters. * Order of authors arranged alphabetically PDF

Jensen, O.P., Branch, T.A., and R. Hilborn. 2012. Marine fisheries as ecological experiments. Theoretical Ecology. PDF

Hilborn, R., Stewart, I.J., Branch, T.A., and O.P. Jensen. 2012. Defining trade-offs among conservation of species diversity, profitability, and food security in the California Current bottom trawl fishery. Conservation Biology. PDF

Ricard, D., Minto, C., Jensen, O.P., Baum, J.K. 2012. Examining the status of commercially exploited marine species with the RAM Legacy Stock Assessment Database. Fish & Fisheries. PDF

Melnychuk, M.C., Essington, T.E., Branch, T.A.*, Heppell, S.S.*, Jensen, O.P.*, Link, J.S.*, Martell, S.J.D.*, Parma, A.M.*, Pope, J.G.*, Smith, A.D.M.* 2012. Can catch share fisheries better track management targets?  Fish & Fisheries. * Order of authors arranged alphabetically PDF

Pinsky, M.L., O.P. Jensen, D. Ricard, S.R. Palumbi. 2011. Unexpected patterns of fisheries collapse in the world’s oceans. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1015313108 PDF

Branch, T.A., O.P. Jensen, D. Ricard, Y. Ye, and R. Hilborn. 2011. Contrasting global trends in marine fishery status obtained from catches and from stock assessments. Conservation Biology. DOI: 10.1111/j.1523-1739.2011.01687.x PDF Press

Salomon, A.K., S. Gaichas, O.P. Jensen, V.N. Agostini, N.A. Sloan, J. Rice, T. McClanahan, R. Fujita, M. Ruckelshaus, P. Levin, N.K. Dulvy, and E.A. Babcock. 2011. Bridging the divide between fisheries and marine conservation science. Bulletin of Marine Science. 87(2):251-274. PDF

Hutchings, J.A., C. Minto, D. Ricard, J.K. Baum, O.P. Jensen. 2010. Trends in the abundance of marine fishes. Canadian Journal of Fisheries & Aquatic Sciences. 67:1205-1210. PDF

Worm, B., R. Hilborn, J.K. Baum, T. A. Branch, J. S. Collie, C. Costello, M. J. Fogarty, E. A. Fulton, J. A. Hutchings, S. Jennings, O. P. Jensen, H. K. Lotze, P. M. Mace, T. R. McClanahan, C. Minto, S. R. Palumbi, A. M. Parma, D. Ricard, A. A. Rosenberg, R. Watson, D. Zeller. 2009. Rebuilding global fisheries. Science 325: 578-585. PDF