Fishing for blues got you down? Wait a year


April 03, 1991|By PETER BAKER

For the past few years, the spring run of big bluefish has been disappointing -- if not almost nonexistent.

The possible reasons for the slow years are many -- cold water across the mouth of the bay, poor spawning production and long-term overfishing.

This year, if the weather holds and patterns of water temperature off the coast continue to develop as they have since early March, the outlook is brighter.

Still, a really good run of big blues in the spring may be a year off.

So, says the guy in Section 12, Row BB, Seat 4, where do you get your information? A crystal ball?

Sort of.

Like virtually all recreational and commercial species that live in Chesapeake Bay at some time of the year, bluefish are the subject of intensified management plans because stocks have been found to be fully exploited all along the Atlantic coastline.

As a result, it is likely that, starting next month, recreational bluefish catches (8-inch minimum) will be limited to 10 per person per day.

While the management plans and creel limits may be viewed as an infringement -- or even a nuisance -- by recreational fishermen, they also are a way of determining the number of fish available as well as where and when.

To read the "Fishery Management Plan For The Bluefish Fishery" is to learn about where and why bluefish of various sizes migrate (not to mention a fine way to fall asleep on winter nights).

In a nutshell, length of daylight and rises in water temperature trigger the northward migration of the blues from off Cape Hatteras. The larger, older fish seem to tolerate colder water better and begin to move first. The others seem to follow in stages made up of fish of similar sizes.

Two years ago, according to fisheries biologists with the Maryland Department of Natural Resources and the Mid-Atlantic Fishery Management Council, a tongue of cold water extended across the mouth of the Chesapeake. The vanguard of big blues moving north apparently slipped eastward into the Atlantic and around the cold water before heading again inshore.

Last year, however, water conditions at the mouth of the bay were more favorable -- and still the run of big blues did not occur.

Through March last year, said John Foster of the DNR, who monitors satellite mapping of surface isotherms along the Atlantic coast, waters of the bay were colder than the ocean and only the mouth of the bay was in the lower range for bluefish migration.

Adult bluefish have been caught in waters as cold as 9 degrees Celsius, but their mass migrations are triggered by waters about degrees Celsius.

"By May 5, 1990, I was dealing with 12 [degrees Celcius] in the mouth of the bay, 11s and 12s in the bay, and 15 and 17 off the coast," Foster said.

But by then, the big fish were long gone and the bay was invaded by large numbers of smaller fish.

This year, Foster said, water temperatures still are below the migratory trigger, but they are warming uniformly out to 30 miles offshore, which should pick up the schools that will be moving north from Hatteras.

"My guess is that if warm weather continues as it is," Foster said, "that we are likely to get bluefish coming in this year better than what we were in the past, based on temperature.

"Bluefish are always looking for more comfortable conditions, and if the bay is more comfortable [than the ocean], they are coming in."

The number of fish that will be coming in also should be better. The reason is that the 1989 spawn produced the best numbers since 1984, according to Christopher M. Moore, fishery management specialist for the MAFMC.

In the 1980s, there have been only three strong years for reproduction, 1981, 1984 and 1989. The worst year on record is 1988.

The spread of those successful spawning years -- and the collapse of 1988 -- may mean that a strong year of early big blues still may be a year off.

According to the biological profile of bluefish, some may live for 11 or 12 years. But results from trawl surveys have turned up virtually none nine years and older. So it follows that the boom of 1981 long has been bust and the boom of 1984 is surely going that way from natural or unnatural causes.

But the 1989 class, now 2 years old and largely sexually mature, should be between 15 and 20 inches and still growing fast. But these will not be spring choppers until next year or the year after. The brutes that might have come this spring from the 1988 class virtually do not exist.

"It is always going to be a combination of abundance and availability to account for declining or increasing catches, and water temperature has an important role, especially in Chesapeake Bay," Moore said.

"You now have this 1989 year class that will be available. But the big ones that they were catching back in 1988, 1987, those probably have been fished out.

"But 2- or 3-pound fish should be abundant."

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