Invasive Mussels Threaten Shipwreck Alley

Posted: February 25, 2013  |  By: Megan Gannon [Live Science]

Known as Shipwreck Alley, Thunder Bay in northwest Lake Huron presents a forbidding scene for boaters and captains but a wonder for divers and marine archaeologists. Its chilly bottom is dotted with dozens of wrecks, from 19th-century schooners to passenger-carrying steamboats to steel-moving freighters that have fallen prey to the bay's unpredictable weather and dangerous shoals.

More than 50 of these historic hulks are protected by the Thunder Bay National Marine Sanctuary, which was created in 2000 and covers 448 square miles (1,160 square kilometers) off the northeast coast of Michigan's Lower Peninsula. Though most are in relatively good shape, thanks to the wreck-friendly freshwater environment of Lake Huron, a new report released by the National Oceanographic and Atmospheric Administration (NOAA) finds the sunken ships might be threatened by a tiny menace: invasive mussels.

A few decades ago, zebra and quagga mussels were introduced to the Great Lakes, likely by ocean-going vessels from Europe dumping ballast water. Researchers believe the mollusks' quick domination of lake-bottoms in the region has contributed to the recent decline of some native species, such as the commercially valuable whitefish. (It's thought that the mussels, through competition, have depleted populations of the shrimplike Diporeia, which is an important part of the whitefish's diet.) 

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