Measuring the status of fisheries and factors leading to success

This talk will summarize the results to date of our SNAPP group of the same title.  We will summarize the data we have available on the status of fish stocks,  and how they are managed.
We now have reliable data from national and international scientific institutions on stocks constituting over 50% of global fish catch, with Asia south of Japan the major area that is not covered.  We also have less reliable estimates from  statistical models of most fisheries not covered by scientific assessments.  We have also collected data on how fisheries are managed in major fishing countries and international fisheries.  Our best estimates are that globally fish stock abundance has been stable for the last several decades,  but increasing in places were good scientific data are available and likely decreasing where such data is not available.  Our preliminary results suggest that there is not a strong relationship between the intensity of fisheries management and stock status because intensive management seems to result from poor stock status.  If we focus on stocks that are overfished then a clear relationship between intensity of management and stock recovery emerges.
At our current meeting we are asking two key questions.  (1) what factors have led to recovery of overexploited species and (2) Does science advice improve fisheries outcomes.
Ray Hilborn
Mike Melnychuk
Maite Pons
Ray Hilborn

Ray Hilborn

Ray Hilborn is a Professor in the School of  Aquatic and Fishery Sciences, University of Washington specializing in natural resource management and conservation. He  teaches graduate and undergraduate courses in food sustainability, conservation and quantitative population dynamics.  He authored several books including “Overfishing: what everyone needs to know” (with Ulrike Hilborn) in 2012,  “Quantitative fisheries stock assessment” with Carl Walters in 1992, and “The Ecological Detective: confronting models with data” with Marc Mangel, in 1997 and has published over 300 peer reviewed articles.  He has served on the Editorial Boards of numerous journals including  7 years on the Board of Reviewing Editors of Science Magazine.    He has received the Volvo Environmental Prize, the American Fisheries Societies Award of Excellence, The Ecological Society of America’s Sustainability Science Award,  and the International Fisheries Science Prize.    He is a Fellow of the American Fisheries Society, the Washington State Academy of Sciences, the Royal Society of Canada and the American Academy of Arts and Sciences.
Mike Melnychuk is a Research Scientist at the University of Washington’s School of Aquatic and Fishery Sciences, working with Ray Hilborn. His research focuses on characterizing the variability in fisheries management systems around the world and assessing the consequences of that variability for fish stocks and fisheries. In previous lives, Mike completed his PhD at UBC with Carl Walters and Villy Christensen, studying migration and mortality patterns of juvenile salmon, and then completed a post-doctoral fellowship at UW with Tim Essington, quantifying ecological impacts of catch share fisheries.
Maite Pons is a PhD. student working with Ray Hilborn in the School of Aquatic and Fishery Sciences, University of Washington. She is originally from Uruguay where she completed her undergrad in biology and masters in ecology. Her research focuses in stock assessment and management of large pelagic species such as tunas and billfishes. She is interested not only in the performance of different assessment models but also in how different management measures impact current stock status.
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Salmon management and responses to water quality changes in Alaska [Wed. March 23]

This week’s Roundtable features two talks about salmon ecology and management in Alaska by Drs Milo Adkison and Anne Beaudreau, both of whom are members of the Gulf of Alaska Portfolio Effects working group.

Why is salmon management so hard?

Dr. Milo Adkison

Managers of Alaskan salmon fisheries open and close fisheries on short notice, with the objectives of maximizing catch and achieving their goal for spawners escaping the fishery. Uncertain run strength has long been recognized as an impediment to their success. I’ll show that uncertain run timing is just as big of a problem. Finally, I’ll examine a constant fishing schedule as an alternative to the current management approach.
University of Alaska Fairbanks
235 O’Neill
Fairbanks, AK 99775

Long-term community responses to nutrient additions and water quality changes in Afognak Lake, Alaska

Dr. Anne Beaudreau

The Afognak Lake sockeye salmon run historically supported one of the largest subsistence fisheries in the Kodiak Archipelago, Alaska. Declining abundance during the 1980s led to a decade of lake fertilization (i.e., additions of phosphorus and nitrogen) and intermittent stocking. The central goal of this study was to characterize changes in prey and habitat quality for lake-rearing juvenile sockeye salmon in Afognak Lake since the late-1980s. We synthesized long-term data collected by the Alaska Department of Fish and Game to address two questions: (1) What environmental and ecological factors explain patterns of production for zooplankton and juvenile sockeye salmon in Afognak Lake? (2) Are patterns of production consistent with the expected community response to fertilization? We found that total phosphorous concentration was an important predictor of variation in density and size of dominant zooplankton species. Primary and secondary production showed a response to lake nutrient additions, but there was no discernable effect of fertilization on juvenile sockeye size and condition. Additionally, there was little support for the hypothesis that larger size at outmigration led to enhanced survival in the ocean. As a whole, our results suggest that nutrient additions are unlikely to result in increased population productivity of Afognak sockeye and that the ecological role of insects, which compose a large proportion of sockeye fry diets in Afognak Lake, deserves greater attention.

Beaudreau halibut_photo
University of Alaska Fairbanks
17101 Point Lena Loop Road
Juneau, AK 99801


A Network Approach to Assessing Social-Ecological Systems in the Cook Islands (Nov 10)

A social-ecological system approach emphasizes the connectivity that exists between natural and human systems. This coupling is evident at a local scale, with people accessing natural resources for food provisioning and economic gain, and ecosystems providing services such as storm protection and food security. At a larger scale, institutions, and regional and global ecological processes influence how systems function. I present findings from research in Colombia and the Solomon Islands where social networks, institutions, livelihoods, and local ecological knowledge were analyzed to determine the factors that influence an individual’s motivation to comply with marine resource management and to withstand large-scale ecological disturbances. Finally, I propose a network-based approach to quantify social-ecological system interaction and assess the drivers of resilience in the Cook Islands.

Dr. Jaime Matera
Anthropology Program
California State University Channel Islands

Matera Pic