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Publications
Julia K. Baum and Boris Worm. Cascading top-down effects of changing oceanic predator abundances. Journal of Animal Ecology, 2009.
Abstract
Top-down control can be an important determinant of ecosystem structure and function, but in
oceanic ecosystems, where cascading effects of predator depletions, recoveries, and invasions could be significant, such effects had rarely been demonstrated until recently. Here we synthesize the evidence for oceanic top-down control that has emerged over the last decade, focusing on large, high trophic-level predators inhabiting continental shelves, seas, and the open ocean. In these ecosystems, where controlled manipulations are largely infeasible, ‘pseudo-experimental’
analyses of predator–prey interactions that treat independent predator populations as ‘replicates’, and temporal or spatial contrasts in predator populations and climate as ‘treatments’, are increasingly employed to help disentangle predator effects from environmental variation and noise. Oceanic top-down control can have important socio-economic, conservation,
and management implications as mesopredators and invertebrates assume dominance, and recovery of overexploited predators is impaired. Continued research aimed at integrating across trophic levels is needed to understand and forecast the ecosystem effects of changing oceanic predator abundances, the relative strength of top-down and bottom-up control, and interactions with intensifying anthropogenic stressors such as climate change.
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