MEPS 324:37-55 (2006)  -  doi:10.3354/meps324037

Ozone treatment of ballast water on the oil tanker S/T Tonsina: chemistry, biology and toxicity

Russell P. Herwig1,*, Jeffery R. Cordell1, Jake C. Perrins1, Paul A. Dinnel2, Robert W. Gensemer3,7, William A. Stubblefield3,7, Gregory M. Ruiz4, Joel A. Kopp5,8, Marcia L. House1,9, William J. Cooper6

1School of Aquatic and Fishery Sciences, Box 355020, University of Washington, Seattle, Washington 98195-5020, USA
2Shannon Point Marine Center, Western Washington University, 1900 Shannon Point Road, Anacortes, Washington 98221, USA
3ENSR International, 4303 West LaPorte Avenue, Fort Collins, Colorado 80521, USA
4Smithsonian Environmental Research Center, 647 Contees Wharf Road, PO Box 28, Edgewater, Maryland 21307-0028, USA
5Petrotechnical Resources Alaska, 310 K Street, Suite 407, Anchorage, Alaska 99510, USA
6Department of Chemistry and Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, USA Present addresses:
7Parametrix Inc., 33972 Texas Street Southwest, Albany, Oregon 97321, USA
8Consulate General Monterrey, US State Department, PO Box 9002, Brownsville, Texas 78520, USA
9Northwest Indian Fisheries Commission, 6730 Martin Way East, Olympia, Washington 98516, USA

ABSTRACT: Worldwide transfer and introduction of non-indigenous species in ballast water causes significant environmental and economic impact. One way to address this problem is to remove or inactivate organisms that are found in ballast water. In this study, 3 experiments were conducted in Puget Sound, Washington, USA, using a prototype ozone treatment system installed on a commercial oil tanker, the S/T Tonsina. Treatment consisted of ozone gas diffused into a ballast tank for 5 and 10 h. Treatment and control tanks were sampled during the ozonation period for chemistry, culturable bacteria, phytoplankton and zooplankton. Selected fish and invertebrates were placed in cages deployed in the treatment and control tanks. Ozone introduced into seawater rapidly converts bromide (Br) to bromines (HOBr/OBr), compounds that are disinfectants. These were measured as total residual oxidant (TRO). Ozone treatment inactivated large portions of culturable bacteria, phytoplankton and zooplankton. The highest reductions observed were 99.99% for the culturable bacteria, >99% for dinoflagellates and 96% for zooplankton. Caged animal results varied among taxa and locations in the ballast tank. Sheepshead minnows and mysid shrimp were most susceptible, shore crabs and amphipods the least. Distribution of ozone in the treatment tank was not homogenous during experiments, as suggested by the observed TRO concentrations and lower efficacies for inactivating the different taxa in selected ballast tank locations. Low concentrations of bromoform, a disinfection byproduct, were found in treated ballast water.

KEY WORDS: Aquatic nuisance species · Non-indigenous species · Ballast water · Ozone treatment · Bromine · Total residual oxidant

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