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.
As usual, Roundtable will take place in the NCEAS lounge at 735 State Street, Suite 300.
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When does hypoxia affect management performance of fisheries? A MSE of Dungeness crab fisheries in Hood Canal, WA

Hypoxia [dissolved oxygen (DO) < 2 mg/L] is one of the key threats to some of the most productive regions of the marine environment (e.g., estuaries). Although mortality can occur, mobile organisms have the potential to avoid the most severe low oxygen conditions, but suffer ecologically significant indirect and sublethal impacts as a result. In Washington State, USA, a fjord estuary of the Puget Sound marine ecosystem, known as Hood Canal (110 km), regularly experiences seasonal hypoxia. My dissertation addresses several important gaps in the current knowledge pertaining to the non-lethal biological effects of hypoxia on the mobile benthic and pelagic species of Hood Canal – for the sake of time and your sanity, I’ll be focusing on the benthos. Using acoustic telemetry, I quantified movement patterns and distributional shifts of Dungeness crab (Metacarcinus magister), an abundant and widely distributed species. Although highly mobile, Dungeness crab displayed more localized, rather than large-scale, directional movement relative to hypoxia. More specifically, the tagged crabs showed significant distributional shifts towards shallower waters. As one of the most important fisheries in Puget Sound, I wanted to then investigate the generalized relationship between hypoxia and the Dungeness crab harvest (3-S) management strategy. Inferred by the shoaling behavior from the field, an age-structured population model was constructed to test several hypoxia-scenarios with other stressors, including harvest, illegal crab fishing, and incidental capture mortality. It was found that the 3-S management strategy is most sensitive to the influence of hypoxia when other sources of demographic restrictions are considered, underscoring the uncertainty associated with a data-poor species under multiple anthropogenic and environmental stressors.

FieldWork_2010_HoodCanal Tagged_Crab


Halley E. Froehlich, Ph.D. (Halley is the untagged one on the left)

Postdoctoral Researcher

National Center for Ecological Analysis & Synthesis
University of California, Santa Barbara



A spectral framework for forecasting near term inland fisheries in the Mekong River under climate change

John Sabo, a visiting researcher from Arizona State University, will be presenting this week’s roundtable! He will be telling us about his work in the ecologically and economically important Mekong River Basin. We will be continuing the climate change theme from last week’s talk, but moving onto its impacts on fisheries instead. He will also discuss how dams have impacted the river and fisheries.

Abstract:  Inland capture fisheries on the Mekong River provide a majority of the animal protein and vitamin A to the diets of over 40M people in the Lower Mekong River Basin.  The productivity of this fishery is fueled by the monsoon flood pulse which creates wetlands the size of small US states in Cambodia and Vietnam.  The region is experiencing rapid development, including the planning and impending construction of over 20 hydropower facilities, some already built.  Climate change will also likely change the intensity and timing of the South Asian Monsoon, with implications for the extent of the ensuing flood pulse and the fishery that depends on it.  In this roundtable I will address two topics.  First, I present the results from a century scale analysis of change in hydrologic variation and key aspects of the flood pulse on the Mekong River including an assessment of current dams.  This analysis is done within a novel spectral framework that allows for identification of baseline stationarity and decomposition of the linear, seasonal and stochastic components of change in daily discharge.  Second I link spectral measures of hydrologic variation to catch data from the fishery using a 15-year dataset of the Dai fishery on the Tonle Sap River (Cambodia) and a second time series approach—a multivariate autoregressive state space (MARSS) model.   The spectral-MARSS framework is then used to forecast the fishery under near time climate change.   Daily discharge variation and key aspects of the flood pulse have been experiencing natural change for over a century. Existing dams have modified discharge in spite of a shifting baseline.  Fisheries catch varies with several spectral measures of daily discharge variation.  Surprisingly, low flows have equal if not higher positive effect sizes than high flows on catch in this flood pulse system and spectral measures outperform “first moment” measures of flood pulse extent.  Moreover, antecedent hydrology—the flood drought sequence from the previous 1-2 years—significantly affects current catch in the fishery.  These results suggest that the spectral-MARSS framework may provide a robust tool for forecasting fisheries production in the future.

Trey Riel 2

Do synthesis centers produce novel, potentially transformative research? Research publication diversity as an indicator of novelty and transformative capacity


a few of the topics that emerged in our analysis

For this Roundtable, I will present a poster that I presented at the recent AAAS meeting in San Jose. The project is an outgrowth of a working group jointly supported by NCEAS and NESCent and led by Ed Hackett and John Parker. Please read the abstract below for a bit of background, and then come prepared to discuss how you think academic publications (including yours!) produced through synthesis center work might be measurably different from other publications in the field. Then we’ll see if your intuitions are supported by the data we have available. Prepare yourselves to either be really proud of your keen intuitions, or to be surprised by our results!


You can access the poster on figshare using this link:

Update: To initiate discussion prior to the meeting, I’ve put a question up on Tricider, and I welcome you to use the link below to add your ideas, comment on others’ ideas, and/or vote on the ideas that have been suggested. The question is the following:

“How would you expect academic publications that report on synthesis research to differ from publications resulting from other research approaches?”
Here is the link:
Synthesis is an emerging synthetic method for producing transformative research, and publications centers to promote synthesis are on the rise in the US and around the world. New analytic tools and techniques are needed to assess the originality and transformative potential of synthesis. We propose that research outputs produced within synthesis centers will exhibit distinctive qualities that distinguish them from other publications in their fields. To explore this possibility, we conducted a topical analysis of titles, abstracts, and keywords for approximately 400,000 articles published in 108 leading journals from the fields of Ecology, Evolutionary Biology, Biodiversity Conservation, Forestry, and Fisheries. We then described each document as a proportional combination of the discovered topics, and used the Rao-Stirling heuristics to estimate, for each document, various measures that illuminate contrasting aspects of diversity (i.e. variety, balance, and disparity). We then compare diversity metrics for the synthesis center documents with those for all other documents in our corpus to evaluate whether and how the measured diversity of synthesis center publications differs from that of other publications in the relevant fields.