Monday, September 24, 2012

'Dead zones' could happen in the Great Lakes

Matthew Hall in the Holland Sentinel (Michigan): Scientists are studying how extreme weather associated with climate change may produce more of the algae that create dead zones in the Great Lakes. Figuring it out may help government agencies manage the threat algae poses in light of further projected changes in climate.

Climate change presents a “perfect storm” for the Great Lakes because the sequence and intensity of extreme weather creates just the right conditions for blooms to flourish, said R. Jan Stevenson, co-director of Michigan State University’s Center for Water Sciences. He heads a research team studying the situation.

This past summer, dry conditions and hot weather have contributed to pea soup conditions in parts of Lake Macatawa at Holland. The Ottawa County Health Department issued no-body-contact warnings for two local beaches in August.

Over the next three years, the work will include modeling of Muskegon Lake in Muskegon County, Saginaw Bay in Lake Huron, Grand Traverse Bay on Lake Michigan and the Grand River – the state’s longest river — which is one of the biggest sources of nutrients that flow into Lake Michigan, Stevenson said.

Algal blooms are rapid increases in algae caused by an excess of nutrients like the phosphorus and nitrogen often used in farm fertilizers. Harmful blooms can produce natural toxins. And when they die and decompose, they use up dissolved oxygen, creating a “dead zone” that suffocates fish and other organisms....

Lake Huron, viewed by NASA

No comments: