In:
eLife, eLife Sciences Publications, Ltd, Vol. 3 ( 2014-01-21)
Abstract:
Ocean ecosystems are under pressure from overfishing, climate change, habitat destruction and pollution. These pressures have led to documented declines of some fishes in some places, such as those living in coral reefs and on the high seas. However, it is not clear whether these population declines are isolated one-off examples or, instead, if they are sufficiently widespread to risk the extinction of large numbers of species. Most fishes have a skeleton that is made of bone, but sharks and rays have a skeleton that is made of cartilage. A total of 1,041 species has such a skeleton and they are collectively known as the Chondrichthyes. To find out how well these fish are faring, Dulvy et al. worked with more than 300 scientists around the world to assess the conservation status of all 1,041 species. Based on this, Dulvy et al. estimate that one in four of these species are threatened with extinction, mainly as a result of overfishing. Moreover, just 389 species (37.4% of the total) are considered to be safe, which is the lowest fraction of safe species among all vertebrate groups studied to date. The largest sharks and rays are in the most peril, especially those living in shallow waters that are accessible to fisheries. A particular problem is the ‘fin trade’: the fins of sharks and shark-like rays are a delicacy in some Asian countries, and more than half of the chondrichthyans that enter the fin trade are under threat. Whether targeted or caught by boats fishing for other species, sharks and rays are used to supply a market that is largely unmonitored and unregulated. Habitat degradation and loss also pose considerable threats, particularly for freshwater sharks and rays. Dulvy et al. identified three main hotspots where the biodiversity of sharks and rays was particularly seriously threatened—the Indo-Pacific Biodiversity Triangle, Red Sea, and the Mediterranean Sea—and argue that national and international action is needed to protect them from overfishing.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.00590.001
DOI:
10.7554/eLife.00590.002
DOI:
10.7554/eLife.00590.003
DOI:
10.7554/eLife.00590.004
DOI:
10.7554/eLife.00590.005
DOI:
10.7554/eLife.00590.006
DOI:
10.7554/eLife.00590.007
DOI:
10.7554/eLife.00590.008
DOI:
10.7554/eLife.00590.009
DOI:
10.7554/eLife.00590.010
DOI:
10.7554/eLife.00590.011
DOI:
10.7554/eLife.00590.012
DOI:
10.7554/eLife.00590.013
DOI:
10.7554/eLife.00590.014
DOI:
10.7554/eLife.00590.015
DOI:
10.7554/eLife.00590.016
DOI:
10.7554/eLife.00590.017
DOI:
10.7554/eLife.00590.018
DOI:
10.7554/eLife.00590.019
DOI:
10.7554/eLife.00590.020
DOI:
10.7554/eLife.00590.021
DOI:
10.7554/eLife.00590.022
DOI:
10.7554/eLife.00590.023
DOI:
10.7554/eLife.00590.024
DOI:
10.7554/eLife.00590.025
DOI:
10.7554/eLife.00590.026
DOI:
10.7554/eLife.00590.027
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2014
detail.hit.zdb_id:
2687154-3
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