SI Vault
Edited by Jerry Kirshenbaum
October 29, 1984
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October 29, 1984


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In the last decade, the catch of striped bass, the premier game and food fish of the Atlantic Coast, has dropped by a catastrophic 90%.

Now in a weak attempt to save what's left, President Reagan this week is expected to sign into law the Atlantic Striped Bass Conservation Act, which mandates a 55% reduction in the catch from North Carolina to Maine by July 1 of next year. The bill, which was introduced by Representative Gerry Studds (D., Mass.), also authorizes the Secretary of Commerce to impose a moratorium on striped-bass fishing in the waters of any state that does not comply with the 55% reduction.

The bill is better than nothing, but it has its flaws. In fact, it got through the Senate only after minority leader Robert Byrd, a Democrat from the coal-producing state of West Virginia, threatened to kill it unless an amendment requiring that particular attention be given to the effect of acid rain on striped bass be deleted. The bill falls far short of the moratoriums called for by Representative Claudine Schneider (R., R.I.) and Senator John Chafee (R., R.I.), who was responsible for the $5 million Emergency Striped Bass Study authorized in 1979. It also doesn't pack the wallop of Maryland's September announcement of a moratorium on striper fishing in that state as of Jan. 1. In giving reasons for the ban, Secretary Torrey C. Brown of the Maryland Department of Natural Resources cited "recent studies on acid rain, bioassays on fish eggs and larvae, measurement of brood stock size and spawning success and, most important, the Maryland young-of-the-year index," which indicates spawning success or failure. This year, the index was a dismal 4.2, and Brown said that the moratorium will last until the index is at least 8.0 for three consecutive years.

Not long ago, this magazine offered the hypothesis that acid rain is significantly responsible for the low rates of survival of striped-bass larvae and those of six other fish species in poorly buffered tributaries of Chesapeake Bay (SI, April 23). Acid rain can impart an acid pulse to a body of water that has little total alkalinity or buffering capacity. Acidity is measured on the pH scale, which runs from acidic on the low end to alkaline at the high. A pH of 7 is neutral. Research has shown that larval striped bass do best in alkaline water and have difficulty tolerating pH levels of less than 7. New field and laboratory research sponsored by the U.S. Fish and Wildlife Service strengthens that hypothesis.

Last April, aquatic toxicologist Lenwood Hall of Johns Hopkins headed a team that found that larval striped bass placed in the Nanticoke River on the Eastern Shore of the Chesapeake suffered excessive mortality rates. A total of 3,000 day-old larval stripers were put in six chambers set at three different stations in the spawning reach of the Nanticoke. Automatic samplers took water from the river every 15 minutes, and composite samples from each 24-hour period were preserved so that they could be analyzed for dissolved aluminum and other contaminants that can be mobilized by acidity.

After four days in the river, more than 90% of the larval striped bass were dead, while control larvae kept in clean alkaline water in tanks on shore had a 25% mortality. The experiment was repeated with similar results. "The factors we feel are responsible are low pHs—approximately 6.3—high aluminum concentrations and very soft fresh water [indicating little buffering capacity]," Hall says.

Meanwhile at the National Fisheries Research Laboratory in Columbia, Mo., Dr. Paul Mehrle supervised a series of bioassays and found that 10-day-old bass suffered 100% mortality in water with a pH of 5.5. At pH 6.5 with 100 micrograms per liter of aluminum added to the test water, mortality was 85%.

With acidification apparently triggering the decline in Chesapeake stripers, the well-buffered Hudson River remains the only major reliable source of supply on the East Coast. Although the Atlantic Striped Bass Conservation Act notes that habitat loss has contributed to the reduction of striped bass, it doesn't mandate habitat protection, a deplorable omission.

In support of Westway, a massive highway-real-estate project proposed for lower Manhattan, Governor Mario Cuomo of New York wants a permit from the U.S. Army Corps of Engineers to fill in more than 200 acres of the Hudson that serve as vital nursery grounds for young striped bass.

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