by C.D. Dollar
Low Menhaden Numbers May Mean Unhealthy Rockfish
As anglers make the switch from trolling to chumming for rockfish, heres something to think about: the Bays menhaden, from which the soupy concoction is made, could be so stressed that it has caused problems for the Bays striper stocks.
It was a question that some of the Bays best fisheries experts batted around last week at the 60th Annual Northeast Fish and Wildlife Conference in Ocean City.
For several years, scientists, charter captains and guides and recreational fishermen have suspected something wasnt quite right with our local stripers. Most agree theres probably a predator-prey imbalance in Chesapeake Bay. The real question: how bad is it?
Preliminary reports indicate it is bad enough, and several groups are encouraging the Atlantic States Marine Fisheries Commissions Striped Bass Management Committee, which meets this week in Virginia, to study the problem.
Wed like to see the ASMFC Striped Bass Management Committee endorse a scientific study to determine whether there is regional depletion of menhaden of the size that are forage for striped bass in Chesapeake Bay, says Ken Lewis of the Coastal Conservation Association, who also serves as Marylands representative on the Marine Fisheries committee.
Several studies have shown that the abundance of forage-size menhaden the ideal protein-packed snack for growing rockfish has declined to a near historic low. Couple this with the fact that rockfish population has vaulted to a historic high in the past decade, and the table is set for predator-prey issues.
Additionally, tagging studies in both Virginia and Maryland during the 1990s show rockfish survival trends have declined significantly: from 60 to 70 percent in the early- to mid-1990s down to 40 to 50 percent in the late 1990s and early 2000s. Rockfish experts say that resident rockfish are younger males that are poorly nourished compared to those studied around 1990, when previous comparable data were collected. Yet there hasnt been a correlating increase in fishing mortality due to harvest, which suggests to researchers that the declines are a result of natural mortality.
The nutritional health of Bay rockfish is also of major concern. Many of us have caught skinny or sickly looking rockfish. Researchers attribute the poor body condition to lowered fat levels and to disease.
Science has revealed that mycobacteriosis a progressive disease that impacts fishs internal organs, particularly the spleen infects a huge percentage of rockfish. Yet only about 20 percent of the fish infected exhibit external lesions or other signs. Most likely, the disease develops over several years and is fatal in many cases. Perhaps most startling is that it is typically uncommon outside of aquaculture, but it is now one of an increasing series of bacterial outbreaks affecting wild Chesapeake rockfish.
Menhaden is managed only commercially. Huge numbers of menhaden are processed for protein-based products, mainly feed meal and oils. The menhaden fleet that runs out of Reedville, Va., accounts for the lions share of the bunker landings, making it one of the largest ports per volume in the country.
But the importance of menhaden goes well beyond its monetary value. As a filter feeder, menhaden could, if stocks were managed differently, take more excess plankton out of the Bay, which would reduce algal blooms. As a primary forage for large predators such as rockfish, bluefish and sea trout, its fuel for life. We need to find out how full that tank is well before the warning light goes off.
Fish Are Biting
The handful of people Ive spoken say head south for quality rockfish. After several tough outings, Capt. Jim Brincefield motored to the Airplane Wreck and chummed up 30 obese rockfish from 17 to 27.5 inches as well as several croaker, including a portly citation fish 2.7 pounds for Thomas C. Snedeker of Arlington.
Offshore anglers may want to know that NOAA Fisheries is holding a scoping meeting for Atlantic Highly Migratory Species at 7-9pm on Wednesday, June 2, at the Ocean City Council Chambers. For more information, go to www.nmfs.noaa.gov.
State biologists are trying to figure out what has been killing hundreds of white perch found floating in several pockets of water from the Susquehanna River to the West River.