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Researchers Say Five Deep-Water Fish Species Qualify for Endangered Status

Posted on: Wednesday, 4 January 2006, 21:00 CST

ST. JOHN'S, N.L. (CP) - They may not be prime dinner table fare, but the dramatic decline of five deep-water fish species has researchers again warning that the world's oceans are in deep trouble.

In an article published Wednesday in Nature, a prestigious peer-reviewed journal, researchers from Newfoundland's Memorial University describe a 17-year decline in the number of blue hake, spiny skate, two types of grenadier and the spiny eel.

"This is one more piece of information in a trail of other reports that fisheries generally and ocean ecosystems are in trouble," biology professor Dr. Richard Haedrich said in an interview.

"Here are fishes that nobody has heard of, that nobody really cares about, but we take as part of the fact that the whole ecosystem is being impacted."

These fish populations have dropped so dramatically that each species should be added to the list of critically endangered species, the report concludes.

But the World Conservation Union, which oversees the endangered species list, has yet to begin evaluating deep-sea fish.

Scientific interest in ecosystem changes within the deep-sea fishery have intensified with the collapse of the North Atlantic cod stocks in the early 1990's, said Haedrich, who worked on the report with students Krista Baker and Jennifer Devine.

Earlier studies have shown a sharp decline in the number of sharks, rays, tuna, marlins, swordfish and sea turtles.

The researchers found that all five species, which live near or on the bottom of the ocean, have declined in relative abundance, but the numbers for the roundnose grenadier and the onion-eye grenadier were particularly startling.

Over three generations, estimated declines in "relative abundance" were 100 per cent and 99.7 per cent respectively, based on the survey data compiled from research trawls conducted between 1978 and 1994 in Canada's portion of the northwest Atlantic.

"Relative abundance is an index of what's out there," said Devine, one of the report's authors. "We know a lot of these species move, but within what we have the data for, we are seeing this decline range."

The researchers noted that none of these fish was landed in any substantial numbers, even accidentally as so-called by-catch, before the 1970s.

But that changed when fish stocks on the continental shelf collapsed, prompting a switch to deep-sea fishing in the 1970s.

Even though none of the five types of fish studied is considered commercially valuable, they are often caught in nets set for turbot and redfish.

The species studied are slow to recover from disturbances because they grow slowly and don't reproduce until their late teens, the report said.

The report's authors argue that more scientific investigation is needed to determine what is happening with the deep-sea fisheries, but conservation measures are immediately needed despite the lack of knowledge.

Devine said the researchers hope their work leads to policy changes and the creation of deep-sea protected areas, like those created for inshore habitat.

Source: Canadian Press

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