For the last ten years, the Canadian government has had a moratorium on cod fishing in the hope that the population would recover, but it has not.
"My studies suggest that reducing fishing might not be sufficient to ensure recovery," said Hutchings.
Much Uncertainty
"Scientists have little knowledge of the factors that are critical for cod survival," Hutchings said.
It is known, for one thing, that cod require an underwater environment with much vertical scaffolding, such as seaweed and coral. But these have been destroyed by decades of bottom trawling—a fishing technique that essentially ploughs the ocean floor.
Methods to identify genetic variations between cod populations from different regions are necessary for developing tailored management strategies, the researchers say.
"There is a tendency to treat all cod the same," said Hutchings. "But different populations, although all members of the same species, generally don't interbreed. Their migratory and spawning times vary and they have adapted to fit specific locations," he explained.
"Preserving genetically different cod populations is important for biodiversity reasons because a void left by an extinct cod population is unlikely to be filled by a population from another region," said Hutchings.
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