Oswego, NY -- Lake Ontario is the most stressed of the five Great Lakes, a new study that maps environmental threats to the lakes shows.
The study by the Great Lakes Environmental Assessment and Mapping Project, led by researchers at the University of Michigan, identifies how “environmental stressors” are shaping the future of the lakes, which account for 20 percent of the world’s fresh water.
Those stressors, 34 in all, include coastal development, climate change, invasive species and toxic chemicals.
Current conditions do not, however, mean the lake is doomed. One of the authors of the report said Thursday that Lake Ontario can be saved and made healthy again.
“Think about 1976. Lake Erie was declared dead. The rivers were on fire, and it was a cesspool,” said Gregory Boyer, chair of the chemistry department at State University College of Environmental Science and Forestry in Syracuse. “But some people said, ‘Let’s go ahead; let’s fix it up.’ It took 30 years for it to turn around.”
For Lake Ontario, the most severe stressors are invasive species such as zebra and quagga mussels, nitrogen runoff and toxic pollution from mercury and PCBs.
Boyer said the runoff and toxic chemicals are transported to the lake from the cities and industries along the Oswego, Genesee and Niagara rivers. Nitrogen specifically flows into these tributaries as a result of spillover from municipal sewage systems.
This is true in Oswego. The city signed a consent decree with the state and federal governments a couple of years ago to fix its West Side Wastewater Treatment Plant, at an estimated cost of $87 million, so sewage no longer enters the Oswego River.
That work, Boyer said, is one step toward bringing Lake Ontario back to good health. Cleaning Onondaga Lake, which runs into the Oswego River and then to Lake Ontario, also will help.
The GLEAM map shows Lake Ontario colored predominantly red with some areas of orange, the top two levels of environmental stress. There are no areas shaded yellow, green or blue, which indicate less stress.
The maps also show that nitrogen, zebra and quagga mussels, and mercury and PCB pollution are prevalent in nearly all areas of the lake. Other stressors show up in smaller places, such as the power plants at Scriba and outside Rochester; charter fishing near the cities; and ballast water pollution in port areas.
Key to the future, according to Boyer, is that the stressors shouldn’t be looked at individually, but taken together. What the study did, he said, was “identify the hot spots, and then we can focus on some of these areas that seem to have more cumulative stress.”
“Lake Ontario shows so red on the map because of the multiplicity of stressors,” David Allan, the project’s lead researcher and a professor of aquatic sciences at the University of Michigan, said.
“Current efforts to conserve, manage and restore the Great Lakes often take a piecemeal approach, targeting threats one by one,” Allan said. “We need to recognize that the Great Lakes are affected by multiple environmental stressors and devise strategies based on a full reckoning.”
One problem with Lake Ontario that probably can’t be fixed is the influx of invasive species. Boyer said zebra mussels and other species have been introduced to the Great Lakes through shipping and, once here, are difficult to eliminate.
“The problem with invasives is they are easier to keep out than to get rid of them,” Boyer said.
For more information
Go to this website link to check out the Great Lakes Environmental Assessment and Mapping Project. To see the interactive maps, click on Lake Stressors. To see each individual stressor for the lakes, click on the icon on the right top of the map that looks like three white pages. Click on the individual stressors to see how they affect the various lakes.
Lake Ontario stressors
Stressors should not be looked at individually as harmful. But taken cumulatively, they cause stress to a lake.
Decreased ice cover
Water temperature warming
Invasive species including round goby, sea lamprey and zebra and quagga mussels
Nonpoint nitrogen loading
Nonpoint sediment loading
Toxins including mercury, sediment copper and sediment PCBs.
Rank of lakes for stress:
From most to least stressed: