A bit of a mystery in Port Tobacco River fish story

Advocates find many menhaden, few crabs, stripers, yellow perch

Wednesday, July 2, 2008

Click here to enlarge this photo Submitted photo Frank Cowherd, left, and Davie Skulski position a seining net in the Port Tobacco River at Chapel Point State Park on Saturday morning during a fish survey conducted by volunteers with the Southern Maryland chapter of the Coastal Conservation Association and Port Tobacco River Conservancy. E-Mail This Article | Print This Story Click here to enlarge this photo Submitted photo Chris Milensky, left, Melanie Upright, Mark Webster and Don Upright pick debris out of a seining net the Southern Maryland chapter of the Coastal Conservation Association and Port Tobacco River Conservancy volunteers used to do a fish survey in the river at Chapel Point State Park on Saturday morning.

Volunteers with the Southern Maryland chapter of the Coastal Conservation Association — a national organization that advises and educates the public on conservation of marine resources — and the Port Tobacco River Conservancy arrived at the park off Chapel Point Road at 8 a.m. Saturday to conduct the survey. The conservancy is a group of local environmentalists that formed in 2001 to keep an eye on the river and devise ways to improve its health.

The survey, which has been conducted annually at four sites in Southern Maryland since 2001, netted some surprising results, said Ken Hastings, CCA’s yellow perch coordinator. Hastings said the primary reason for the river seining is to keep an eye on the yellow perch population in local waterways, particularly at spots where the association has conducted restocking activities.

The river conservancy asked the association to conduct a survey in the Port Tobacco River although no restocking of yellow perch is done there, Hastings said.

The weekend’s activity netted 117 white perch, 158 Atlantic silversides, 59 croakers and 541 menhaden, Hastings said, adding that the high number of menhaden that was caught is extremely unusual.

Menhaden, filter feeders which are a primary source of nutrition for most species that live in the Chesapeake Bay, including blue crabs, are caught commercially in Virginia and North Carolina waterways for their omega 3 protein that is used in many natural vitamin supplements, Hastings said. The lack of menhaden is also possibly contributing to the sores often found on striped bass that are caught in the bay and its tributaries, he said.

‘‘There’s a short supply of menhaden in the bay,” he said. ‘‘To net more than 500 is pretty neat. They help keep the bay clean. Overfishing of the species [by Virginia watermen] is depleting local waterways. Normally we only catch two or three.”

Menhaden lay their eggs in the Atlantic Ocean and after they hatch they are swept back into the bay, said Phil Angle, a member of the CCA and the river conservancy.

‘‘They irrigate until they reach the tributaries where they grow very rapidly,” he said, adding that 137 metric tons of menhaden are caught annually in Virginia and North Carolina. ‘‘Basically, everything that you eat that comes out of the bay is menhaden. All the species depend on menhaden as a basis for food.”

The lack of blue crabs, yellow perch and striped bass caught during the seining of the river is a little disturbing, Hastings said.

‘‘We haven’t caught any adult blue crabs,” he said. ‘‘It’s really strange that we caught so many of a species that we didn’t expect to see and we didn’t catch what we expected to catch.”

The surveys are conducted three weekends a month during June, July and August and it is uncertain what future seining activities will produce, Hastings said, adding that the CCA might conduct an additional survey in the fall to check on the blue crab situation.

‘‘There’s a rush of crabs that are ready to hibernate in the water during September,” he said. ‘‘If we don’t net any then we’ve really got a problem.”

The survey also netted some rare species normally not found in the river — two juvenile pipefish, 10 needlefish and at least 34 shrimp, Hastings said, adding that everything that was caught in the net during the seining was thrown back into the water.

The seining is an excellent way to keep an eye on the diversity of aquatic species that live in the Port Tobacco River, said Melanie Upright, a member of the river conservancy who coordinates yellow perch spawning surveys for the organization.

‘‘It’s an opportunity to share with people about the wonderful things that happen in the river,” she said. ‘‘It’s incredible. You wouldn’t know in a million years the diversity of the species that live in the river.”

The survey also lets conservationists know exactly what species are thriving and which are not in the river, Upright said.

‘‘We need to know what resides in our river so as a community we can better appreciate what we have there,” she said, adding that the data that are retrieved from the surveys are important information to pass along to local legislators. ‘‘It’s hard for our legislators to decide what changes to make to improve the water quality without this data. Surveys provide invaluable information for decision making.”

Twenty-one volunteers turned up to participate in Saturday’s seining, Upright said.

‘‘Everybody was so invigorated,” she said.

Hastings said that the participation of river conservancy members was astounding.

‘‘It’s kind of neat; the organization has a strong stewardship of the Port Tobacco River and they were pretty excited about the seining,” he said. ‘‘It made it a banner day for us. It’s really important for us to get people out there to share in the experience.”

‘‘It was very successful,” Angle said.

‘‘The idea was to get a bunch of people from the Port Tobacco River Conservancy out there to watch and learn about the river to help in their efforts to monitor and protect the river. It opened a bunch of eyes up to just how rich the river is despite the pollution of human waste that often spills into the waterway.”