Several species of Atlantic deep-water fish have been so ravaged by overfishing that they should be classed as critically endangered, a rating that is even higher than for the giant panda and Bengal tiger, a study says.
Canadian biologists carried out an assessment of five deep-sea species to see how these fish were affected by a shift to deep trawling prompted by the collapse of shallow-water coastal fisheries.
Over 17 years, the five species declined by at least 87 percent and up to 98 percent, the scientists found.
“They meet the (World Conservation Union, IUCN) criteria for being critically endangered,”the paper, to be published today in the British weekly science journal Nature, says.
“Our results indicate that urgent action is needed for the sustainable management of deep-sea fisheries.”
The five species studied ranged from the common to the rare.
They were the roundnose grenadier; onion-eye grenadier; blue hake; spiny eel; and spinytail skate.
In addition, there was survey data for two of the species (the roundnose and onion-eye grenadiers) for the period from 1995-2003. In these two cases, the decline over the 26-year study period was 99.6 and 93.3 percent respectively.
The authors, led by Jennifer Devine of Memorial University at St. John's, Newfoundland, say the findings provide powerful backing for anecdotal evidence that deep-water trawling is having a catastrophic impact on deep species.
“Deep-sea fish are highly vulnerable to disturbance because of their late maturation, extreme longevity, low fecundity and slow growth,”they note.
Some species cluster together in large numbers for spawning, which also makes them more susceptible to overtrawling.
The five species they studied live up to 60 years, grow up to more than a meter (3.25 feet) in length but only become sexually mature in their teenage years.
Translated by Jessie Liu 翻譯：劉婉瑀