USACE PLAN TO PREVENT ASIAN CARP FROM SPREADING THROUGH BRANDON ROAD LOCK AND DAM
By Cori Marshall
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Asian Carp make intermittent headlines in North America. The presence of the four species in any aquatic environment on the continent should set off alarm bells, due to the complete and total transformation that occurs in a given habitat once they are established. Yet there are times when news of the invasive fish is hard to come by.
The words Asian Carp do not refer to one specific species, and when we refer to the fish in North America we are speaking of the Bighead, Black, Grass, and Silver Carp. The four species were introduced to the continent five decades ago in the southern United States, and have since made their way north. The four species have a kind of symbiotic or complementary existence which allow the fish to completely dominate an environment where they can represent nearly all the biomass in a body of water.
Stopping the spread of these invasive fish has become a task for the U.S. Army Corps of Engineers (USACE) and the Great Lakes Mississippi River Interbasin Study (GLMRIS) in the Chicago area. The army engineers have released a Draft Report on the Tentatively Selected Plan (TSP) to stop the carp from crossing from the Mississippi River Basin into the Great Lakes. Allen Marshall, Chief of Corporate Communications USACE, took the time to speak with us about the draft report.
Marshall explained that the GLMRIS had "released a study in 2014 in which they were looking to [develop] different prevention methods against the spread of Aquatic Nuisance Species (ANS)." He added that within the study "there were several options that were identified for evaluation." Marshall said that the study "identified a one-way control point," at Brandon Road Lock and Dam part of the 45 km Chicago Sanitary and Ship Canal.
USACE was tasked "to evaluate the potential options [and technology at the Brandon Road Lock and Dam to prevent the upstream interbasin transfer of [ANS] like the Asian Carp."
The TSP that was ultimately identified by USACE "is a technology alternative with complex noise and an electric barrier," Marshall Said. He added that "there are also non-structural measures that are part of the plan."
There are five structural control measures in the TSP. The first is complex noise, which generates underwater sound to keep ANS from entering the approach channel to the lock. Some of you may be asking if fish hear, no they donít though Marshall explained that "the fish would feel the sound as pressure." The noise is not constantly generated because the fish "would adapt" and no longer be effective.
The second component is the Electric Dispersal Barrier. The barrier creates a field that is used to "repel and stun" the fish and would be placed downstream of an engineered channel. The channel is the third component and would be used to enhance some of the controls put forward in the study.
the TSP includes a Flushing Lock and Water Jets. These components are designed clean ANS from vessels and to prevent those that float from entering the lock itself.
The TSP has been presented for public review and comment. The public will have a full opportunity to have their opinions heard either online or at one of the three public meetings September 11, 14, and 18. Asian Carp have been present in the Great Lakes since the early 2000s and as we know they have made their way to the St. Lawrence River, any means to stem the tide of their spread is a step in the right direction.