Great Lakes waterbird health suffers at polluted sites despite cleanup efforts

LANSING — Despite decades-long efforts to clean up toxic hot spots along Michigan’s Great Lakes shores, a recent study shows that the health of waterbirds in some areas continues to suffer.

Researchers examined 10 years of data on fish-eating birds living near Saginaw Bay, the River Raisin and Grand Traverse Bay. 

Those sites have a history of industrial pollution, including chemicals linked to reproductive problems, deformities and immune system problems in waterbirds.

The results showed that infertility and weakened immune systems were more prevalent at the contaminated sites than in birds in more pristine areas along Lake Superior at the St. Marys River.

The study also found that immune systems and birth defects in herring gulls and Caspian terns at the contaminated sites didn’t improve from 2010 to 2019. In a few cases, health outcomes grew slightly worse. 

Keith Grasman, the study author and a biology professor at Calvin University, said the lack of improvement is especially concerning for Caspian terns, which are rare in the Great Lakes and listed as threatened in Michigan.

“When we study and find effects of pollutants on this relatively rare species, it tells us something about the need to clean up pollution to help improve their populations,” Grasman said.

The pollution includes classes of chemicals known as PCBs and PCDDs. Decades of research have linked them to birth defects and dead embryos in birds. 

PCBs were used in products including military equipment, electrical transformers and paint. Their production was banned in the U.S. in 1979, but the chemicals persist in the environment without breaking down.

The damaging biological effects continue despite “significant earlier efforts to control sources of PCBs in and along the lower Saginaw River and lower River Raisin,” according to the study, published in the journal Environmental Toxicology and Chemistry.

While the results of the study are disappointing, that kind of monitoring helps focus cleanup resources where they’re needed most, said Kylie McElrath, the Michigan conservation manager with the Great Lakes office of the National Audubon Society, a bird and wildlife conservation group.

“Despite the bans on some of these pollutants since the 1970s, there are still these long-lasting impacts on our bird species,” McElrath said. “I think that it’s a good informative study to help better target conservation and remediation efforts.”

Waterbirds prey on fish and are important to the ecological stability of the Great Lakes ecosystem. They’re also a useful tool for scientists as indicators of the health of the ecosystem as a whole, McElrath said.

“By monitoring what bird species are present, it can be indicative of what the quality of the wetland is,” she said.

The River Raisin and the Saginaw River and Bay are both listed as “Areas of Concern,” a group of around 40 contaminated sites across the U.S. and Canadian Great Lakes shorelines. 

Grasman said preserving the Great Lakes and wild birds also requires a focus on prevention.

The public can play an important role in that effort by educating the next generation of citizens, he said. 

“It’s really important for parents to help educate their kids on these kinds of environmental problems,” Grasman said. “Not just on pollution, but other environmental problems in the Great Lakes. They can learn about these issues and then be better citizens as adults.”

Joshua Kim writes for Great Lakes Echo.