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Whales sustain fisheries: blue whales stimulate primary production in the Southern Ocean


Lavery, TJ and Roudnew, B and Seymour, J and Mitchell, JG and Smetacek, V and Nicol, S, Whales sustain fisheries: blue whales stimulate primary production in the Southern Ocean, Marine Mammal Science, 30, (3) pp. 888-904. ISSN 0824-0469 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Society for Marine Mammalogy

DOI: doi:10.1111/mms.12108


It has previously been asserted that baleen whales compete with fisheries by consuming potentially harvestable marine resources. The regularly applied "surplus-yield model" suggests that whale prey becomes available to fisheries if whales are removed, and has been presented as a justification for whaling. However, recent findings indicate that whales enhance ecosystem productivity by defecating iron that stimulates primary productivity in iron-limited waters. While juvenile whales and whales that are pregnant or lactating retain iron for growth and milk production, nonbreeding adult whales defecate most of the iron they consume. Here, we modify the surplus-yield model to incorporate iron defecation. After modeling a simplistic trajectory of blue whale recovery to historical abundances, the traditional surplus-yield model predicts that 1011 kg of carbon yr−1 would become unavailable to fisheries. However, this ignores the nutrient recycling role of whales. Our model suggests the population of blue whales would defecate 3 106 kg of iron yr−1, which would stimulate primary production equivalent to that required to support prey consumption by the blue whale population. Thus, modifying the surplus-yield model to include iron defecation indicates that blue whales do not render marine resources unavailable to fisheries. By defecating iron-rich feces, blue whales promote Southern Ocean productivity, rather than reducing fishery yields.

Item Details

Item Type:Refereed Article
Keywords:whale, iron, ecosystem, ocean fertilization, blue whales, baleen whales, whaling, fisheries, carbon, ecological history, marine populations, productivity, Balaenoptera musculus, allochthonous nutrients, autochthonous nutrients, nutrient cycling
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the environmental sciences
UTAS Author:Nicol, S (Dr Stephen Nicol)
ID Code:93254
Year Published:2014
Web of Science® Times Cited:49
Deposited By:IMAS Research and Education Centre
Deposited On:2014-07-22
Last Modified:2017-11-01

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