The Role of Pinnipeds in the Ecosystem

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9

stron

6592

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University of British Columbia

1998

rok

Abstract

The proximate role played by seals and sea lions is obvious: they are predators and consumers of

fish and invertebrates. Less intuitive is their ultimate role (dynamic and structural) within the

ecosystem.

The limited information available suggests that some pinnipeds perform a dynamic role by

transferring nutrients and energy, or by regulating the abundance of other species. Others may

play a structural role by influencing the physical complexity of their environment; or they may

synthesize the marine environment and serve as indicators of ecosystem change. Field

observations suggest the ultimate role that pinnipeds fill is species specific and a function of the

type of habitat and ecosystem they occupy. Their functional and structural roles appear to be most

evident in simple short-chained food webs, and are least obvious and tractable in complex long-

chained food webs due perhaps to high variability in the recruitment of fish or nonlinear interactions

and responses of predators and prey.