Research

Change in Presque Isle Bay status based on Penn State Behrend analysis

Catfish study suggests Erie ecosystem has recovered

A 20-year study of bullhead catfish in Presque Isle Bay prompted state and federal regulators to reclassify the water's environmental quality. A statistician from Penn State Erie, The Behrend College, found patterns in the study's data. Credit: presqueisle.orgAll Rights Reserved.

ERIE, Pa. -- The U.S. Department of State’s decision to lift Presque Isle Bay’s designation as an area of environmental concern was based on more than 20 years of research, much of it led by the staff at Pennsylvania Sea Grant, a partnership of Penn State Erie, The Behrend College; the Commonwealth of Pennsylvania and the National Oceanic and Atmospheric Administration.

“It took a lot of work to get to this point,” said Eric Obert, extension director for Pennsylvania Sea Grant. His involvement in the project began in 1990, when he helped tag and track 2,000 brown bullhead catfish for the Pennsylvania Department of Environmental Protection.

Bullheads are a good indicator species. Because they are bottom-feeders and have no scales, they are susceptible to the effects of pollution. The 1990 study, which was designed to estimate the population of bullheads in Presque Isle Bay, found plenty with problems: 65 percent of the fish had skin lesions.

Another 21 percent had liver tumors. That was a key reason the bay was designed an “Area of Concern” under the Great Lakes Water Quality Agreement. Environmentalists supported the move, which brought federal attention – and funding – to the pollution in the water.

In the years since, as conditions improved, experts continued to watch the bullheads. They photographed skin tumors and tested the bile from fish gall bladders. With the help of Michael Rutter, an associate professor of statistics at Penn State Behrend, they tracked not only the weight, length and gender of the fish they caught, but also their age. Biologists calculate that by cutting open the fish’s otolith, an inner ear bone, and counting the growth rings.

Rutter examined trends in the data, which was shared by Pennsylvania Sea Grant, the Presque Isle Bay Public Advisory Committee, the Pennsylvania Department of Environmental Protection and the U.S. Fish and Wildlife Service.

“We standardized it,” he said. “They had data back to the ’80s and early ’90s, but the collection methods kept changing. Different people were looking for different things, and age was not always part of it.”

It needed to be. Older fish are far more likely to develop tumors.

The researchers are still finding liver tumors: 2.8 percent of 7-year-old Presque Isle bullheads have them, according to Rutter. But at two of the Lake Erie reference sites, the rate is even higher.

One in every five of the fish still has a skin tumor, Obert said. The reasons for that are not entirely clear.

Even so, the Presque Isle Bay Public Advisory Committee recommended in July that the bay be removed from the “Area of Concern” list. Just one other U.S. site – the lower Oswego River in New York – has rebounded from “Area of Concern” status.

In January, the U.S. Environmental Protection Agency said it would support the change. In February, the Department of State, which has the last word in the matter, agreed to lift the “Area of Concern” designation.

“That felt good,” Rutter said. “It was nice to be involved in something concrete, and local, that solved a problem with a major body of water.”

Last Updated April 4, 2013

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