Zebra and quagga mussels have already made homes in the Great Lakes region, but there's another invasive clam on the horizon we should keep our sights on. While still limited to countries in South America, researchers predict that the golden mussel could colonize areas in North America where zebra and quagga mussels could not, devastating what native clam populations remain.
Originally from China, the golden mussel was introduced to Argentina around 1990 by way of ballast water. The microscopic size of its larvae combined with its ability to attach to aquatic plants, ships, and fishing equipment has made its spread difficult to contain. By 2006, the golden mussel had made its way to Brazil, Bolivia, Uruguay, and Paraguay, where they now cost communities an estimated $200,000 a day in industrial and ecological losses.
Like zebra and quagga mussels, golden mussels clog pipes and alter food webs wherever they spread — only the golden mussel takes things a step further. Considered an “ecosystem engineer,” large populations of golden mussels often completely change the biological makeup of a lake's sediment.
Because they are filter feeders, golden mussels greatly deplete the amount of suspended material in a water column, which in turn depletes the water's oxygen levels. The end result is an ecosystem that favors detritivores and invertebrates like leeches, caddisflies, and other species that can live in the nooks and crannies golden mussels create, and are able to feed on golden mussel fecal matter. And native clam species stand little chance of survival as golden mussels have been known to surround and grow on top of them, starving them to death by sealing them shut.
We'll have more species spotlights on aquatic invaders throughout May in honor of Illinois Invasive Species Awareness Week.