Between the Trees Blog

Underwater Acoustic Deterrent System: Upgrades to Protect the Great Lakes from Invasive Carp

Written by Kimberly Walters | January 18, 2024

We are at the Lock and Dam 19 facility in Keokuk, Iowa, operated by the U.S. Army Corps of Engineers (USACE). Our team replaced an 18,000-LB, 105-FT underwater soundbar with wet-mateable connections (cables and speakers that can be connected and disconnected underwater). This underwater acoustic deterrent system (UADS) upgrade allows divers to replace individual speakers if underperforming rather than continuing to remove the entire system.

Why? The U.S. Geological Survey (USGS) is spearheading a 3-year study to reduce the number of invasive carp moving toward the Great Lakes. It is the only study on the Mississippi River evaluating a deterrent for invasive carp. 

Underwater Acoustic Deterrent System Upgrades at Lock 19 

Deploying underwater acoustics is a selective strategy because of the hearing range of invasive carp. Focusing on the sounds that only carp can hear and react to, the USGS plans to deter them.  

Shareable on YouTube: https://youtu.be/efkZAs1UUzc?si=rNpcAj9HeuvH4lWv

"Not only is Nelosca very knowledgeable about Army Corps operations, they're knowledgeable about locks as well as dams. So, working with them, they have solutions." – Christa Woodley, Ph.D., U.S. Army Engineer Research and Development Center.

The three-year invasive carp study has the following objectives:

  1. Design and install a UADS in the downstream lock approach channel.
  2. Evaluate the effectiveness of the UADS to deter upstream passage of fish into the lock chamber.
  3. Evaluate the behavior of invasive carp and native fishes relative to UADS operation and covariates.
  4. Evaluate the UADS operational performance over the study duration.

"We've been able to work with Nelosca over the last few years now and have people that really know what's going on. It's a unique system both in the design and the repair aspects of it, and so familiarity with it has been really important. "– Marybeth Brey, Ph.D., USGS.

Underwater Acoustic Deterrent System Repair Photographs 

Thank you to the U.S. Geological Survey, the U.S. Army Engineer Research and Development Center, and the Lock and Dam 19 operations staff.
 
Dig into our Diver-Assisted Dredging and Capping Used in the Cuyahoga River Improvement Project and Repairing Fish Guidance Nets at a Hydropower Dam for more examples of underwater work!
 

 

About Nelosca Technologies
Nelosca Technologies, Inc. (Nelosca) is a fourth-generation, family-owned marine construction firm specializing in environmental remediationdam constructioncommercial diveharbor management, and submarine cable services. Working closely with public and private owners of water-based infrastructure since 1919, Nelosca operates nationwide throughout coastal and inland waterways.