Document Detail

The absence of sharks from abyssal regions of the world's oceans.
MedLine Citation:
PMID:  16777734     Owner:  NLM     Status:  MEDLINE    
The oceanic abyss (depths greater than 3000 m), one of the largest environments on the planet, is characterized by absence of solar light, high pressures and remoteness from surface food supply necessitating special molecular, physiological, behavioural and ecological adaptations of organisms that live there. Sampling by trawl, baited hooks and cameras we show that the Chondrichthyes (sharks, rays and chimaeras) are absent from, or very rare in this region. Analysis of a global data set shows a trend of rapid disappearance of chondrichthyan species with depth when compared with bony fishes. Sharks, apparently well adapted to life at high pressures are conspicuous on slopes down to 2000 m including scavenging at food falls such as dead whales. We propose that they are excluded from the abyss by high-energy demand, including an oil-rich liver for buoyancy, which cannot be sustained in extreme oligotrophic conditions. Sharks are apparently confined to ca 30% of the total ocean and distribution of many species is fragmented around sea mounts, ocean ridges and ocean margins. All populations are therefore within reach of human fisheries, and there is no hidden reserve of chondrichthyan biomass or biodiversity in the deep sea. Sharks may be more vulnerable to over-exploitation than previously thought.
Imants G Priede; Rainer Froese; David M Bailey; Odd Aksel Bergstad; Martin A Collins; Jan Erik Dyb; Camila Henriques; Emma G Jones; Nicola King
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Proceedings. Biological sciences / The Royal Society     Volume:  273     ISSN:  0962-8452     ISO Abbreviation:  Proc. Biol. Sci.     Publication Date:  2006 Jun 
Date Detail:
Created Date:  2006-06-16     Completed Date:  2006-07-24     Revised Date:  2013-06-07    
Medline Journal Info:
Nlm Unique ID:  101245157     Medline TA:  Proc Biol Sci     Country:  England    
Other Details:
Languages:  eng     Pagination:  1435-41     Citation Subset:  IM    
Oceanlab, University of Aberdeen, Newburgh, Aberdeen AB41 6AA, UK.
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MeSH Terms
Behavior, Animal*
Oceans and Seas
Sharks / physiology*
Species Specificity

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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