Thursday, February 19, 2009

NOAA Study Documents Invasives Disruption In Lakes' Food Web

Feb 18: Scientists from NOAA say the quick decline of a tiny shrimp-like species, known scientifically as Diporeia, is related to the aggressive population growth of non-native quagga mussels in the Great Lakes. As invasive mussel numbers increase, food sources for Diporeia and many aquatic species have steadily and unilaterally declined. A recent research study from NOAA’s Great Lakes Environmental Laboratory published this week in Freshwater Biology documents the recent decline of Diporeia and the explosive growth of quagga mussels in Lake Michigan. Over the past five years quagga mussels have displaced native Diporeia as the dominant bottom dwelling organism, leading to a major disruption in the lake’s food web.

Tom Nalepa, NOAA research biologist said, “Quagga mussels have displaced other more energy-rich food sources and leave fish and other aquatic species with fewer food options. The invasive mussels are low in calories and their shell has no nutritional value. Fish feeding on quagga mussels expend considerable energy crushing and passing the indigestible shell.”

Access a release from NOAA (click here). Access an abstract of the paper and information on obtaining the complete paper (click here).

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