Residual toxicity testing and chemical characterization of ballast water following treatment with NaOH, sparging with scrubbed marine diesel engine exhaust, and aeration Active

Overview of Study Plan:  The Great Lakes are experiencing unprecedented introductions of invasive species through the release of fouling organisms in ballast water (BW). Agencies (US Coast Guard, USEPA, International Maritime Organization) tasked with regulating ballast water and limiting negative impacts upon ecological systems of the Great Lakes need to approve and recommend quick and inexpensive methods for onboard treatment of BW. To meet this time-critical challenge, Barnaby Watten (USGS) developed a method to kill a diverse assemblage of fouling organisms and to neutralize that toxicity prior to BW release.  The study involved complex toxicity experiments conducted both shipboard and in land-based laboratories requiring an understanding of aquatic toxicity testing as well as ballast and effluent discharge criteria. Collaborators included USGS Columbia Environmental Research Center, Chesapeake Biological Laboratory, Moss Landing Laboratory, US Army Corps of Engineers, National Park Service, lawyers, and consultants.  Data were interpreted with respect to multiple ballast water discharge criteria of the US Coast Guard, USEPA, and International Maritime Organization. The results provide validation for this novel, elevated pH-based treatment to significantly reduce organism densities in freshwater ballast with little to no toxicity remaining in the treated ballast water upon discharge. This approach has great potential to become the first successful ballast water treatment system for use in freshwater systems.

Sources/Usage: Public Domain.