A tale of rescue in the nick of time


January 22, 1994|By TOM HORTON

It is seldom that scientists, amid the fury of battle and against great odds, ride in at the last moment to rescue the damsel in distress.

But if you can handle rockfish as a surrogate damsel, let me take you back to those thrilling days of yesteryear . . . to the 1983 General Assembly.

The previous summer, the Chesapeake Bay's troubled rock had produced a crop of young that was just average, but far better than any spawn for several years.

Commercial landings of rockfish, the bay's premier sport and commercial species, had been plummeting for a decade -- from 5 million pounds in 1973 to a tenth of that in 1983.

Some legislators thought the time had come to protect the fish born in 1982, to let them grow until they could reproduce in 1987.

In the 1983 legislative session, a bill was introduced to end all rockfishing, to mostly jeers and curses from sport and commercial fishermen.

The state Department of Natural Resources joined with watermen in squashing the bill, saying there was a plan to reduce catches by half. But DNR did not realize just how dramatic the striped bass decline had really been; the decline in catches understated the drop in population.

It would turn out that an entire decade of bay rockfish had been virtually wiped out.

Between 1972 and 1981, despite several years of good reproduction, nothing born would survive long enough to make a significant contribution to carrying on the species.

Nor could anyone in 1983 predict that it would be another seven summers before the rockfish had anything like a good spawn again. (This is why conservation agencies are supposed to act conservatively in managing resources.)

Meanwhile, DNR grappled with catch restrictions for the rest of 1983 to afford the rockfish some protection; but political pressure from Eastern Shore legislators and a lawsuit filed by several big rockfish netters kept the department on the defensive.

Things got worse. Reproduction in the summer of 1984 was once again subpar. Fishermen, both sport and commercial, continued hammer the rockfish, not only in the Chesapeake, but all along the annual migratory path in the ocean as far north as Maine.

Many people believed that toxic pollution -- PCBs and other chemicals -- was inhibiting reproduction. Cleaning up the bay is the solution, not taking away our livelihoods, watermen cried.

Late in 1985, this was the situation: The 1982 class of rockfish was reaching legal catching size, and would soon be fished intensively. But there was nothing behind them for 10 generations, and there would be little reproduction to follow them for another six generations.

And the big old females whose eggs had been carrying the bay's rockfish through the decade of wiped-out generations, were close to fading from the fishery through natural mortality.

Those old mothers, ranging in size to beyond 4 feet and more than 75 pounds, were survivors from huge reproductive years in the 1950s and 1960s.

Then, in late 1984, Phillip Goodyear and John Boreman, two federal fisheries scientists studying what was by then a coastwide rockfish crisis, came up with their improved version of what is called a "population dynamics model."

The model convincingly sketched the outlines of the crisis, and what was needed to truly reverse it.

Harley Speir, a fisheries scientist with DNR, recalls taking the first draft of the model in to Secretary Torrey C. Brown. "It gave him something solid and defensible to hang a decision on; I believe it was what tipped the balance," Speir says.

In short order, DNR announced a moratorium on fishing. It caused a furor.

It also saved the 1982 class, which went on to become the basis of a recovery for the rockfish that is now touted as one of the prime success stories in Chesapeake restoration of the last decade.

Even today, many fishermen will say that the moratorium was an overreaction, that the fish would have come back on their own.

They should look at the recent detective work done by David Secor, a scientist at the University of Maryland's Chesapeake Biological Laboratory at Solomons.

Secor has figured how to, in effect, "interview" some of the huge, old rockfish that were around during events of the past few decades.

His work provides an elegant confirmation of much of the scenario above, particularly the dire "generation gap" that threatened to send rockfish to oblivion.

During Maryland's new "trophy season" in 1992, which allowed fishermen one large rockfish each spring from the newly revitalized fishery, Secor collected dozens of "otoliths", thumbnail-sized bones from the heads of large rock.

Sliced and prepared in a lab, the otoliths (literally meaning ear stones) can be read for annual growth rings that show the fish's age, much like rings in a tree stump.

The fish -- only females grow so large -- ranged in age from a 7-year-old all the way back to a grand old specimen hatched in 1961, a new age record for the bay.

But from the years of 1972 to 1981, there were no specimens.

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