Coast Guard Study Shows Minimal Risk of Invasive Species Thru Barges on Great Lakes

By KBJR News 1

Water samples from the St. Croix River have tested positive for genetic material from silver carp, suggesting the invasive, leaping Asian species may be present in the river as far north as the dam at St. Croix Falls, according to the Minnesota Department of Natural Resources.

February 28, 2013 Updated Feb 28, 2013 at 5:05 PM CDT

Cleveland, Ohio (NNCNOW.com) --- A study conducted by the Coast Guard Research and Development Center in coordination with the U.S. Environmental Protection Agency concluded that barge ballast tanks present a minimal risk for incidental transport and introduction of Asian carp into the waters of the Great Lakes.

According to the Coast Guard, there has been concern that Asian carp eggs, larvae and fry contained in towboat and barge ballast tanks could be transported past electrical dispersal barriers and released into the Great Lakes.

Specifically, the study investigated the possibility for early life stages of Asian carp entering barge ballast tanks through either cracks or holes in the hull and then surviving there.

Results of this study indicated that, while it may be possible for early life stages to be transported in a barge ballast tank for long periods, the probability that those life stages will survive passage through the pump when the tanks are deballasted is very low.

The risk is further lowered because early life stages are only present in the affected waterways for a limited time each year.

A previous study evaluated barges and towboats on the Illinois River to determine the volume of water carried in ballast tanks. That study found that only five percent of the tanks inspected carried more than a couple of inches of water.

Operators interviewed during that study indicated that barges were seldom ballasted except to clear low bridges and that tanks were inspected regularly.

The Great Lakes Restoration Initiative, in which the Coast Guard and EPA partner among 14 other agencies to rehabilitate the ecosystem's health, provided funding for the study.

Asian carp are non-native, invasive fish that have been migrating up the Mississippi River and its tributaries since the mid-1990’s.

Posted to the web by Krista Burns