Chapter

Ecosystem Impact of the Decline of Large Whales in the North Pacific

DONALD A. CROLL, RAPHAEL KUDELA and BERNIE R. TERSHY

in Whales, Whaling, and Ocean Ecosystems

Published by University of California Press

Published in print January 2007 | ISBN: 9780520248847
Published online March 2012 | e-ISBN: 9780520933200 | DOI: http://dx.doi.org/10.1525/california/9780520248847.003.0016
Ecosystem Impact of the Decline of Large Whales in the North Pacific

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In the absence of empirical observations, one method to examine the trophic impact of consumers on ecosystems is to assess changes in the amount of net primary production required (PPR) to sustain them. In marine systems, it is estimated that commercial fisheries required 8% of global aquatic primary production to sustain them. This chapter uses a similar approach to assess the potential trophic impact of the historical removal of large whales from the North Pacific pelagic ecosystem. An assessment of the impact of the removal of large whales on energy flow requires estimates of prey biomass consumption rates for each whale species, estimates of pre- and post-exploitation whale populations, estimates of the trophic level and trophic transfer efficiencies of individual whale species, and estimates of the net primary production of the ecosystem.

Keywords: whale removal; PPR; commercial fisheries; pelagic ecosystem; prey biomass consumption

Chapter.  8576 words. 

Subjects: Aquatic Biology

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