Pelagic Fish Stocks on the Move and in the News: Collapse, Recovery, or Something Else?, Part 1*
Monday, August 18, 2014: 1:30 PM-5:20 PM
304A (Centre des congrès de Québec // Québec City Convention Centre)
Small schooling forage fish – such as sardine, anchovy, mackerel, herring, and capelin – are often a crucial trophic link between zooplankton and seabirds, marine mammals, and other fish. Many of these stocks support commercial fisheries. Extreme fluctuations in abundance and distribution are well-documented. Examples include Barents Sea capelin (
Mallotus villosus) stock, which collapsed and recovered three times since 1985, and Norwegian spring-spawning herring (
Clupea harengus), which collapsed to <1% of its former abundance, recovered over three decades, and whose distribution range retracted and expanded by thousands of kilometers. On the other hand, the northern Benguela sardine (
Sardinops sagax) stock collapsed in late 1970s and remains <10% of peak abundance. Why do some stocks recover quickly, but others do not? How does demographic and spatial structure influence population resilience and recovery potential? How does fishing interact with population and spatial dynamics to hinder recovery, and under what productivity conditions? Do shifts in feeding migrations and behavior signal shifts in the trophic dynamics and growth potential of marine ecosystems?
Population dynamics and distributions of forage fish has been the focus of considerable research, correlating changes in environmental factors and fishing pressure with abundance and distribution. Despite this effort, many functional mechanisms remain a mystery. Regional comparisons of stock dynamics, distribution, and behavior may help identify signals of collapse and recovery. Further, the transboundary nature of many forage fish stocks demands international collaboration in research and management of these valuable and ecologically important stocks. The goal of the symposium is to facilitate sharing of knowledge between researchers and managers working with forage fish stocks and their fisheries worldwide. By using comparative approach to forage fish research we will learn more than by focusing on one ecosystem in isolation.
Chairs:
Anna Olafsdottir
and
Erin Carruthers
Organizers:
Anna Olafsdottir
and
Erin Carruthers
Developing Tools for an Ecosystem Approach to Fisheries in the Southern Benguela Marine Social-Ecological System: An Overview
Astrid Jarre, University of Cape Town;
Lynne J. Shannon, University of Cape Town;
Laura K. Blamey, University of Cape Town;
Gregory L. Duggan, University of Cape Town;
James A.E. Howard, University of Cape Town;
Emily S. McGregor, University of Cape Town;
Kate E. Watermeyer, University of Cape Town;
Hilkka O.N. Ndjaula, University of Cape Town;
Sven M. Ragaller, University of Cape Town;
Florian G. Weller, University of Cape Town
Harvest Control Rules for Highly Variable, Environmentally-Driven Species: The Case of the Pacific Sardine (Withdrawn)
Forage Abundance, Quality, and Distribution Drive Food Limitation in an Expanding California Sea Lion Population
Sam McClatchie, Southwest Fisheries Science Center/ NOAA Fisheries;
Mark Lowry, NOAA Fisheries Service;
John Field, NOAA-National Marine Fisheries Service;
Andrew Thompson, Southwest Fisheries Science Center/ NOAA Fisheries;
Ed Weber, Southwest Fisheries Science Center/ NOAA Fisheries;
William Watson, Southwest Fisheries Science Center/ NOAA Fisheries;
Paul Fiedler, NOAA-Fisheries;
Karen Nieto, European Commission Joint Research Center;
Russel Vetter, NOAA-Fisheries;
Daniel Rudnick, University of California