Adrienne Appel in IPS/IFEJ: The weather was right for swimming this summer along the shores of Lake Michigan, but on many days, the only living things seen on the beach were gulls, picking away at zebra mussels ensnared in a thick, green slime that covered every rock, pebble and grain of sand for miles.The slime is Cladophora, a native algae that over the last few years morphed from a well-behaved algae into a green monster that fouls drinking water and beaches, and clogs industrial intake pipes in Lake Michigan, one of the five Great Lakes.
Scientists so far haven't found the reason for Cladophora's overgrowth. The lake is under such profound environmental stress that any of a number of factors, alone or together, could be the cause, they say. "It's easy to see what's happening. It's difficult to understand why," J. Val Klump, director of the Great Lakes WATER (Wisconsin Aquatic Technology and Environmental Research) Institute, told IPS.
Top suspects are climate change, which has raised the lake's temperature and lowered water levels, and the widespread, sinister changes in the lake's ecosystem wrought by alien zebra and quagga mussels that now cover the lake bottom by the millions. "These systems are very sensitive to climate change," Klump said.
This isn't the first time Cladophora, whose growth is fueled by phosphorus and other nutrients, changed into a nuisance plant. It also overgrew in the 1960s and '70s until excess phosphorus pouring into the lake was halted, a byproduct of industry and household products. With phosphorus under control, the Cladophora had been too, until about five years ago….
East coast of Lake Michigan looking west from Big Sable Point lighthouse. Shot by 3bylunch, Wikimedia Commons
No comments:
Post a Comment