Friday, March 26th, 2010
Zebra mussel project chosen for International Science Fair
Grand Lake water woes focus of student's study
By Nancy Allen
Andrew Favorito tests water from Grand Lake last summer at the Celina Water Trea. . .
GRAND LAKE - A high school science fair project proving zebra mussels can lower toxins in Grand Lake by eating the algae that produces it has been selected for the International Science Fair in San Jose, Calif.
Presenting the project will be Andrew Favorito, a junior at Paulding High School. He will be among 1,500 others from around the world participating in the May event. He was picked for the event after placing in the top two of 150 participants at the Northwest Ohio Science and Engineering Fair on March 6 in Archbold.
The 17-year-old had the idea for the project while visiting his grandfather, Don Martindale, who lives on the lake in St. Marys.
"Over Memorial Day weekend I saw the signs posted on the lake and that kind of got the wheels turning," Favorito said. "My family goes up to Lake Erie quite a bit and we have seen what the zebra mussels have done to Lake Erie, and I wanted to see if the zebra mussels could do the same thing for Lake St. Marys."
The signs Favorito saw were erected by the state and warned lake users to limit their contact with the water due to high levels of a microcystin toxin produced by blue-green algae.
For his science project, Favorito hypothesized that zebra mussels could be used to filter the blue-green algae in Grand Lake and lower the levels of the toxin.
A zebra mussel has aquatic benefits because it can filter a gallon of water a day, however, it is an invasive species that can grow and reproduce at an incredible rate. The mussels attach themselves to hard surfaces such as water intake pipes, and become a nuisance.
Favorito first got permission from the state to remove zebra mussels from East 55th Marina in Cleveland, and put them in tanks containing Grand Lake water. He then set up six, 10-gallon tanks containing lake water at his grandfather's home. The control tank held lake water only and the other five held lake water and about 100 zebra mussels each. He performed the actual testing of the water at the Celina Water Treatment Plant under the guidance of plant Supervisor Mike Sudman and Assistant Supervisor Todd Hone.
The results were astounding, the youth said.
"When I first set it up, within a couple hours the water was clear," Favorito said of the five tanks containing the zebra mussels.
He also found that the blue-green algae toxin level in the control tank stayed constant at 90 parts per billion, while the level in the tanks with mussels dropped tremendously, to 4 parts per billion, by the end of the two-week test. The World Health Organization sets the recreational water exposure limit for the toxin at 20 parts per billion.
Favorito said the toxin levels dropped because the zebra mussels ate the algae and it was no longer able to produce the toxin. Blue-green algae is not usually eaten by other organisms, Favorito found during his research.
His experiment proved his hypothesis true. Introducing zebra mussels into Grand Lake water decreased algae toxin levels.
But the problems with the lake are complex and one solution is never enough, especially one that involves introducing an invasive species like the zebra mussel, Favorito concluded.
Sudman said Favorito's project was very interesting, but added that zebra mussels wouldn't survive in shallow Grand Lake because the water gets too cold in the winter. In Lake Erie, the mussels are able to escape the cold by going deeper in the water.
Besides, Sudman said, the mussels are destructive, particularly at water treatment plants, and create maintenance issues.
"Yes we have hard water to treat, one of the hardest in the state. But there are problems we don't have here, and we don't want them," Sudman said about zebra mussels.
Favorito made the following recommendations based on his experiment:
• Reduce the amounts of phosphorous-rich fertilizers in the watershed. Phosphorous that runs off mostly farmland is what feeds the blue-green algae in Grand Lake, EPA tests have shown.
• Restore natural wetlands around the lake to naturally filter incoming water.
• Dredge the existing nutrient rich silt from the bottom of the lake.
• Further examine the potential usefulness of zebra mussels.
Favorito does not advocate the introduction of zebra mussels into Grand Lake, which, he said, "would probably make a lot of people mad." He does think the topic deserves more study.
"I think this would be a last ditch thing and that more testing needs to be done and control methods would need to be made to keep them (zebra mussels) only in Lake St. Marys," he said.
The zebra mussel (dreissena polymorpha) is a species of small, freshwater mussel originally native to the lakes of southeast Russia. It has been accidentally introduced in many other areas, including the Great Lakes, and has become an invasive species in many different countries. The mussels grow and reproduce at an incredible rate and attach themselves to hard surfaces. They have become a nuisance because they clog various water pipes.
The mussels get their name from the striped pattern that is commonly seen on their shells. They are usually about the size of a fingernail, but can grow larger.