Great Lakes Aquatic Habitat News
The Newsletter of the Great Lakes
Aquatic Habitat Network and Fund
Volume 9, Number 5 • September-October 2001
Great Lakes Aquatic Habitat NewsThe Newsletter of the Great Lakes
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by Maria Maybee, Great Lakes United
Recent tests in Canandaigua Lake suggest heavy foam buildup may be due to decaying zebra mussels. “In the past, residents along the eastern shore of the lake have noticed some foam wash up on their shoreline, but never to the extent that has occurred and is still occurring this year,” said Canandaigua Lake Watershed Manager Kevin Olvany. According to Olvany, in the past, the foam has been caused by pollution from phosphate detergents (from dishwashers and washing machines), and the natural breakdown of organic matter. The typical sources of organic matter in Canandaigua Lake are aquatic plants growing in shallow water, he said, as well as microscopic plants and animals throughout the lake.
But Olvany and Bruce Gilman, a conservation professor at Finger Lakes Community College, believe zebra mussels may be dying off in high numbers and producing the foam as they decay. When zebra mussels are plentiful, they eat microscopic plants, which improves the clarity of the lake. Tests by Olvany and Gilman show that the lake is not as clear as it was last year. This suggests zebra mussels are dying, perhaps because they have consumed their main food supply.
“We think natural breakdown of organic matter is the likely explanation (of the foam) this year, but we are still puzzled by the shear volume of it,” Olvany said. The foam, which appears throughout the lake and particularly on the east shore, is arranged by prevailing winds in streaks that can reach 30 to 50 feet wide and 4 to 5 miles long. “When it gets very windy, that’s when you see it,” said Sandy Beach resident Doris LaDonna. “We just can’t get over the amount of it.”
Testing in the lake will continue this fall and Olvany and Gilman plan to contact fellow North American researchers and those in Europe to determine if any other lake ecosystems have experienced similar levels of foam.
Of the nearly five-and-a-half million trout and salmon stocked into Lake Ontario in 1999 by New York State (3.7 million) and the Canadian province of Ontario (1.7 million), how many are surviving and for how long? Answers to questions about the fishes’ survival and growth will come from a New York Sea Grant study by a multitalented “Dream Team” of scientists. New York State’s 750,000-plus licensed anglers, Great Lakes sportfishing business owners (producing an estimated $43 million net value to the state’s economy), and Canadian counterparts eagerly await results of the two-year, $600,000 project.
The scientists are from Cornell and Syracuse Universities, SUNY College of Environmental Science & Forestry, the New York State Department of Environmental Conservation, and the U.S. Geological Survey. Canada’s Ontario Ministry of Natural Resources is lending scientific support to the study by contributing data, fish samples, and access to the province’s archive of otoliths to the study.
One specific research technique involves the extracting of tiny samples of fish otoliths (or ear stones) for chemical analysis. This process can tell much about that fish’s environment, its temperature, growth rate, and location in the food web throughout the individual fish’s lifetime. Over the last several years, biologists on both sides of Lake Ontario have observed considerable yet unknown numbers of naturally produced Chinook salmon, the lake’s top predatory species. These wild fish may equate to additional hungry mouths to feed, over and above the numbers of fish that are stocked.
Results are expected to be available sometime after the team completes its work in early 2002. While research is primarily focused on Chinook salmon, the researchers will also study Coho salmon, and Steelhead and brown trout.
Team members include Patrick J. Sullivan, Clifford E. Kraft, and Edward L. Mills with Cornell University’s Department of Natural Resources; Lars G. Rudstam from Cornell’s Biological Field Station; William P. Patterson, Syracuse University Department of Earth Sciences; Donald J. Stewart, SUNY College of Environmental Science and Forestry; Daniel L. Bishop, Brian F. Lantry and Leslie R. Wedge with the New York State Department of Environmental Conservation; James H. Johnson and Robert O’Gorman with the U.S. Geological Survey. Tom Stewart has been coordinating OMNR’s efforts with respect to this study.
If you need further information send an email to: brngdaylit@aol.com
A vile-smelling algae is raising a stink along the southwestern portion of the Lake Ontario shoreline from Niagara County to Oswego County. The gag-inducing culprit is Cladophora, a threadlike algae that grows on rocks on the lake bottom.
“What’s happened is the temperature of the lake is just about perfect for algae growth,” said Chuck O’Neill, a senior extension associate with New York Sea Grant. “This stuff grows on the bottom, breaks off and forms mats that float in to shore, get caught on rocks and docks, and start to rot. It really stinks,” he said, likening the smell to a manure holding tank.
The warmer-than-usual weather of late has contributed to the problem. Dr. Joseph Makerewicz, Professor of Biological Sciences at the State University College at Brockport said, “It seems more prevalent this year, though there’s no hard evidence to support that.” He said the cause is not fully understood, but didn’t think a change in the lake’s temperature was a major culprit. “It’s not really true that the lake is warmer this year,” he said. Possible contributing factors include phosphorous abatement programs, and the spread of zebra mussels have helped make the lake clearer, allowing sunlight to penetrate deeper. “More light makes it to the bottom, and sunlight is what triggers algae growth”, O’Neill said. Makerewicz also suspects upwelling, a phenomenon where cold, nutrient-rich water deep in the lake moves up, displacing warmer surface water.
The nutrients in the water, as well as phosphorous and nitrogen produced by zebra mussels, provide food for the algae growth, Makerewicz said. Beaches in Monroe County have been especially hard hit, said Rick Elliott, director of environmental health for that county’s health department.