Georges Bank haddock, a mainstay of the New England groundfishery, were depleted to the lowest total levels ever recorded by 1991 and mature fish were at their lowest by 1993.

The stock has started to rebound under conservation measures enacted for Georges Bank groundfish during the 1990s by both the US and Canada.

How many are there? “A lot,” says Dr. Russell Brown, who is in charge of resource surveys. “Right now, we’re measuring by the number of baby fish caught per tow in the trawl survey net, which uses a liner to capture small fish and other sea life. We got an average of about 154 young haddock per tow this autumn. That’s the highest ever recorded in the survey, nearly twice as much as the previous record, and about 30 times the average since 1963,” said Brown.

Beginning this past summer and continuing into the autumn, routine surveys conducted by the North-east Fisheries Science Center aboard the NOAA research vessel Albatross IV caught unusually large numbers of baby haddock, distributed over a wide area from Georges Bank to New Jersey.

The 4-to-8-inch long youngsters were encountered in sea scallop dredge surveys in August, and again in trawl net surveys in October and November.

Subsequent, similar surveys conducted by researchers in the United States and Canada will further refine estimates of the 2003 year-class size as individual’s age and grow large enough to reproduce, and to be harvested. The old catch-per-tow record for “age-zero” fish (those younger than one year) was about 84 fish per tow in 1963, which eventually became the largest group of one-year-old haddock ever observed -- 486 million fish. “This is quite promising, but we’re not home free,” said Dr. Steven Murawski, who leads the center’s effort to track changes in fish populations. “These young fish have to survive their first few years. It’s critical to keep harvests at or below the target rate -- taking about one in five mature fish every year -- and to keep discard at a minimum.” If that happens, researchers believe Georges Bank haddock could be fully rebuilt to 250,000 mt, a level that many thought was unattainable, before the end of the decade. Research also indicates that the haddock stock may have passed an important biological milestone. “Historically, when haddock spawning biomass is above 75 thousand metric tons, the odds of an above-average year-class are 30 times greater than when spawning biomass is below that level,” said Dr. Jon Brodziak, who studies haddock, and the relationship between spawning stock size and production of age-zero fish. “There are about 120,000 metric tons of spawners out there now, the most since 1967, and about ten times what was there in 1993, before groundfish rebuilding began in earnest,” he said. The stock may also be benefiting from optimum conditions for good survival of eggs and larvae.

Printer friendly version

Email this article to a friend