Bountiful rockfish could be a problem fTC

On The Outdoors

November 01, 1998|By Peter Baker | Peter Baker,SUN STAFF

In the past 20 years, rockfish have come full cycle in the Chesapeake Bay, from a species on the edge of collapse to numbers that presently verge on the incredible -- but questions are being raised over whether so many rockfish can be too much of a good thing in Chesapeake Bay.

As yet, neither recreational anglers nor fisheries scientists know the answers to questions about how the large numbers of rockfish affect the food chain in the bay or how the food chain affects the rockfish.

But representatives of both groups are looking for definitive answers. And both will be represented at a Coastal Conservation Association of Maryland symposium "Striped Bass in Crisis?" to be held at Kent Island High School in Stevensville on Nov. 21.

"I guess that everyone has a different opinion on whether it is feast or famine with striped bass [rockfish]," said Sherman Baynard, chairman of CCA-MD and a chief organizer of the symposium. "But many of the striped bass we have been seeing are thin and have visible signs of stress. We feel there is a crisis going on."

Baynard believes the problems with rockfish are related to inadequate populations of forage fish, particularly menhaden, which move into the bay each spring and are a primary food source for rockfish early in the year.

Crabs, silversides, bay anchovies, white perch, soft clams and a variety of other aquatic animals also are in the food chain for rockfish, a top predator in the bay.

Dr. Eric May, a fish pathologist at the University of Maryland Eastern Shore, is conducting the research for a cooperative study of rockfish. The goal of the study is to determine whether rockfish are stressed by the limits of their habitat, and if so, why.

"I am not sure we have enough data yet to comment," said May, an expert on aquatic animal health. "We have checked 400 to 500 fish for weight, length and gut contents, and I have looked at about 115 fish with lesions that suggests there is an ongoing disease process."

May said researchers are unable to pinpoint the cause of the health problems with some rockfish, but he expects that further research will determine whether the apparent disease is driven by habitat conditions or the predator-prey relationship.

"Since 1994 there has been an increasing pattern of striped bass caught with sores or other lesions on their bodies," said May, who is on the panel of state and federal fisheries experts who will speak at the symposium. "This is not Pfiesteria but seems to be isolated organisms associated with the bay that are opportunists, entering the body after a sore or abrasion already exists."

May said timing and the normal life cycle of rockfish have been problems in his research but that the coming of cooler weather should help speed the process.

"The summer data would suggest there is an absence of food, but once water temperatures are over 80 degrees, striped bass stop eating as a natural consequence," said May. "As we reach the cooler periods of the year, we are hoping they will fatten up. It is that data we need to see.

"The question is: What is debilitating these fish?"

In the opinion of Baynard and the CCA-MD, part of the source of problem is mismanagement of aquatic resources in the bay by state and federal agencies.

"The turnaround of the rockfish is a miraculous recovery that should be credited to nature," said Baynard, a retired farmer who grew up in Queen Anne's County and said he is "absolutely not" a scientist. "I don't credit fisheries managers because they were managing striped bass when they crashed."

The species became so depleted in the mid-'80s that the state imposed a rockfish moratorium. Other East Coast states joined in, and regulators declared the rock had rebounded by 1994.

Baynard said the purpose of the symposium, which is free and open to the public, is to bring state and federal agencies together to manage the entire Chesapeake Bay resource rather individual species.

"One of our concerns is that they haven't accepted the need to manage the forage base," said Baynard. "We want to make sure they are making every effort to make sure they are looking at the whole picture.

"We want to be ahead of the curve next time. We can't say a collapse will occur, but we want to ensure it can't happen."

May did not rule out the possibility of rockfish outstripping their food sources and becoming weak and vulnerable to disease as a result. However, he said, further research is needed before a course of intense study of rockfish and their interaction with forage fish and other top predators can be determined.

"We have a multiplicity of pieces to put together in this puzzle," said May. "It is not something you solve in six months or so. We're sort of at the bottom of long hill that we need to go up."

Pub Date: 11/01/98

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