Are the zebra mussel and quagga mussel to blame for the “dead zones” in Lake Erie?
Scientists have found mysterious dead zones, areas without oxygen, in the central basin of Lake Erie, in which Dreissena species may be partly to blame. High phosphorus levels are present once again in Lake Erie, despite controls for chemical pollution. Researchers suspect biological pollution is the reason behind these increases in phosphorus and algae. The dead zones are created when too many nutrients are present, causing algae blooms, followed by die-offs, and as the material decays, oxygen is consumed, producing an oxygen-depleted environment, where no aquatic plants or organisms can survive. Dreissena mussels filter organic material from the water and expel the phosphorus in their pseudofeces. The dead zones are located at depths below 40 feet and it is unclear what is causing these dead zones, however, researchers are currently studying these zones to figure out why this is happening.
