And that ignorance could threaten the future of the $65-million turbot fishery off Baffin Island, one of the few bright spots in the Nunavut economy.
"There's just too much guesswork," said George Rose of Newfoundland's Memorial University, whose co-authored work released last week in Iqaluit was contracted by one of Nunavut's fishing corporations and an environmental group.
"We don't have a good way to age the fish. We don't know when they're maturing. We don't know much about their reproduction and even their growth rates. These are kind of fundamentals of fishery science."
Using industry and government records from 2006 to 2011, Rose concluded that some fisheries vessels are already harvesting too many small fish in violation of federal guidelines.
Those guidelines stipulate not more than 15 per cent of the turbot catch should be smaller than 45 centimetres.
In 2011, more than a third of the haul from trawlers in the northern part of Davis Strait didn't pass that test. Trawlers in the southern end exceeded the level in every year except 2011.
The catch from gill-net vessels were well under the guideline.
"You catch too many small fish and you're going to deplete the stock," said Rose. "What you're doing is robbing future growth in the stock so you won't be able to sustain a fishery at the level that is optimum.
"You're going to decrease the long-term yield by doing that.
"It's not to say we shouldn't have trawlers in the fishery. It's really just to say (that) if there is a small-fish protocol, it should be enforced."
A spokesman from the Department of Fisheries and Oceans wasn't available.
Fishing has become one of Nunavut's success stories. An industry worth about $35 million in 2006 brought in about $65 million worth of fish in 2011.
The total allowable catch has also been increasing. In 2010, the limit in the southern Davis Strait was raised 27 per cent to 7,000 tonnes.
New vessels have entered the industry. Niqitaq Fisheries sent out a newly refurbished vessel in 2011, partially funded by almost $1 million in territorial and federal money. Other ships have been refurbished and expanded.
There are now four companies involved in the turbot fishery off Baffin Island — all Inuit-owned.
But it's all happening without the kind of information needed to tell whether the fishery is sustainable, Rose said.
"It just cries out for more research."
Nunavut also has an emerging shrimp fishery, as well as a small commercial harvest of Arctic char.Suggest a correction