Great Lakes still plagued by plant, animal invasive species

Erie, Pa. — As species of plants and animals continue to spread through Europe via canals that connect their waterways, Ponto-Caspian region animals such as fish and invertebrates remain the most likely to make the trip across the Atlantic Ocean to North America.

The Ponto-Caspian region is an area that includes the Black, Caspian, and Baltic seas and Danube and Dnieper rivers in eastern Europe, including the former Soviet Union countries of Belarus, Moldova, Romania, Russia, and the Ukraine.

England just saw the so-called killer shrimp arrive within its shores in the past few years. This species, which reaches about 1½ inches long, earned its name from its habit of indiscriminately killing smaller invertebrates and even larval fish with their pincers (mandibles), well in excess of those intended for consumption.

The Great Lakes already has the invasive “bloody red shrimp,” which were first seen in 2006 in Lake Michigan and are now found in all but Lake Superior. They are so far considered a more benign species. 

Living in rocky habitats, they can be seen in schools swarming in densities as high as 1,000 per cubic yard near the water’s surface in marinas under the shade of boats and floating docks. 

So far, no ill effects have been documented from their presence, and they may even provide an additional food source for fish.

The “monkey goby” is one of a number of species of this family of fish that have been transported via ballast water or migration through the canals that connect the major European watersheds. 

Researchers in North America consider this species, Dikerogammarus villosus, likely to be transported through ballast water transport to North American ports because of their widespread distribution in European ports that receive trans-Atlantic ships. 

The monkey goby is considered to be less aggressive than the already established round and tube-nosed gobies, but will still occupy the sandy habitat and consume prey already in demand by our declining native species such as darters and sculpins.

Racer, bighead, and knout gobies also are “on the move” in Europe, according to a University of Toledo study conducted on goby DNA in the Caspian-Ponto region. Other species in that region that can live in fresh water are the ginger goby and Syrman goby.

Even through both the United States and Canada now require freshwater ballast to be replaced with saltwater before trans-Atlantic ships may enter the St. Lawrence Seaway, some scientists believe several species can and have survived high salinity conditions long enough to get transported in Great Lakes ports through ballast water discharges.

Categories: News

Leave a Reply

Your email address will not be published. Required fields are marked *