Boris Worm

Assistant Professor, Dalhousie University, Canada

Ecosystem Effects of Fishing Large Marine Predators

Abstract

Boris Worm In this talk I attempt to quantify the magnitude of change in marine predator abundance and diversity and to trace the wider ecosystem consequences. Observational and experimental evidence suggests that top-down effects of marine predators can be pervasive, and can lead to a fundamental reorganization of marine food webs. Functional elimination of single predators or guilds of predators has also triggered increases in mesopredatory fishes and invertebrates, some of which are economically important. While changes can cascade through multiple consumer levels, attenuation of such effects at the zooplankton level may be typical in the ocean. Both geographical variation in species diversity and changes in diversity as mediated by fishing and climate may influence how these effects play out in particular locations. These new findings, suggest oceanic top-down control is more prevalent than has been appreciated, underscoring the need to consider potentially complex ecosystem effects of exploiting marine predators and the importance to maintain these species above thresholds of ecological extinction.

Bio

Boris Worm is a marine biologist and Assistant Professor in Marine Conservation Biology at Dalhousie University in Halifax, Nova Scotia. Boris received his Ph.D. in Biological Oceanography in 2000 from the University of Kiel, Germany. His research interests focus on the causes and consequences of changes in marine biodiversity on a global scale. Of particular interest are the broader ecosystem effects of fishing.

Boris Worm has authored 40 scientific papers, book chapters and one book. His research has repeatedly attracted international media attention, including the New York Times, Washington Post, Time, Newsweek, CNN, among others. He is the recipient of several major research awards and an elected member of the German Junior Academy of Sciences.

Readings

Worm, B. and R.A. Myers. 2003. Meta-analysis of cod-shrimp interactions reveals top-down control in oceanic food webs. Ecology. 84(1): 162-173.

Worm, B. et al. 2005. Global patterns of predator diversity in the open oceans. Science. 309: 1365-1369.

Worm, B. et al. 2006. Impacts of biodiversity loss on ocean ecosystem services. Science. 314: 787-790.

Video

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