Rockfish reproduction may be rebounding this year
By Pamela wood, Staff Writer for the Capitol
Rockfish reproduction was up this year, caused by a combination of favorable weather and conservative management, the state Department of Natural Resources announced yesterday.
The annual survey of "young of year" rockfish - fish hatched last spring - showed an increase over last year, a level that's also above long-term averages.
"It's a real healthy spawn that bodes well for the future," said Eric Durell, a fisheries biologist who supervises the survey.
Teams from the DNR sweep 100-foot-long seine nets 132 times over the summer in different areas of the Chesapeake Bay to find the young of year fish. On average, they found 17.79 fish per seine this year.
Last year's index was 11.44 and the long-term average is about 12.
The catch-and-release survey helps gauge how well rockfish are reproducing, which is important because 75 percent of the East Coast rockfish population spawns in the bay and its tributaries.
Regulators, fishermen, charter boat captains and others with a stake in the bay's rockfish population watch the survey results closely.
Capt. Russ Green, president of the Upper Bay Charter Captain's Association, said he's pleased with this year's index.
"If you have a good young of year index, it means future fishing will be good," Capt. Green said. "That's the major fish we go for in the upper bay."
Capt. Green said when the rockfish population was near collapse in the 1980s and regulators closed the harvest, his business dropped off 50 percent.
While the numbers are up, rockfish, also called striped bass, still face significant challenges. Stripers are showing up with nasty lesions caused by a disease called mycobacteriosis. And there's concern that the rockfish's favorite food, menhaden, is being overfished in the bay. On top of that, rockfish are affected by pollution and dead zones just like other bay critters.
Bill Goldsborough, a senior scientist at the nonprofit Chesapeake Bay Foundation, said the young of year index is a sign that the 1980s moratorium and other conservation measure has worked. But he cautioned that more needs to be done to reduce the human impacts on rockfish - especially poor water quality and a lack of forage fish such as menhaden.
"What it shows is we've been successful in conserving striped bass and rebuilgin their numbers, but we haven't rebuilt their support systems," he said.
This year's young of year class will reach 18 inches, the legal size for most of the rockfish season, in about three or four years. The class wasn't quite good enough to be termed a "dominant class," but does merit being called a "strong class," Mr. Durell said.
An example of a dominant class is 1996, when all five areas surveyed had above-average reproduction for a total index of 59.39. Those fish are now some of the largest fish being hauled in during spring trophy season tournaments.
Mr. Durell said harvest limits allow the small fish to grow and keep too many large, reproducing fish from being caught. Those regulations, combined with mild spring temperatures and average rain, helped along this year's class, he said.
"We manage conservatively. We try to protect the large, spawning fish," Mr. Durell said.
Mr. Durell's team samples rockfish in five areas of the bay: the Choptank, Nanticoke, Patuxent and Potomac rivers and the upper reaches of the bay.
The Eastern Shore's Choptank River had an index of 55.17 this year. And the upper bay - the largest area for spawning - also was above average at 13.24.
While the survey is intended to catch and count rockfish, the DNR researchers also count several other types of fish that appear in their nets.
For the second year, American shad had strong numbers, a positive sign for managers who are trying to restore the fishery after sharp declines.