|
The Problem
Ballast water discharges are the most significant cause of aquatic biological invasions in coastal waters, including the Great Lakes. Ballast water is discharged to U.S. ports at an average daily estimated rate of 40,000 gallons per minute, according to the National Oceanic and Atmospheric Administration. All discharged ballast water contains live organisms. Some 3000 species are routinely transported around the world on a daily basis (National Research Council, 1996). This transport results in the possible introduction of 100s of nonindigenous species to new locations. Although only a fraction of all species introduced into U.S. coastal waters are able to survive in the receiving ecosystem-and some introductions that do establish turn out to be benign-problem invaders have cost the economy hundreds of millions of dollars, and caused major ecological impacts to receiving ecosystems. Currently, treatment of ballast water prior to discharge at the receiving port offers significant promise to help control this problem. However, development of treatment technologies is limited by lack of objective information about effectiveness. The central question is the extent to which a ballast water treatment process (for which there are many candidate approaches) will alter the viability or densities of a variety of marine organisms over time and under a variety of conditions (temperature, salinity, and a host of other variables). Testing treatments exclusively at one scale, whether bench, pilot, or shipboard, yields incomplete information, and so integrated research at a variety of scales is required. Further, to conduct such research, multi-disciplinary collaboration is first needed to define effective measurement technologies and methods. That is, tests at all scales require reliable measurements of organism viability, density, and community composition. A second question relates to the extent to which reductions in densities of viable organisms will reduce risk of establishment of a population(s)in a receiving system. Risk reduction can ultimately be determined only through years of repeated long-term coastal ecological and pathway surveys that can be analyzed for changes in real-life inoculation levels and invasion success. But shorter term controlled growout experiments in mesocosms (e.g. artificial communities in laboratory tanks) offer a way to measure population recovery for ballast water surrogate species, following test treatment at various levels. These experiments are a first step toward defining the residual risk of biological invasion resulting from discharge of treated water, in which parameters related to
To address these issues, this research involves initial international collaboration on measurement technologies and methods, followed by bench/mesocosm experiments conducted at the Western Fisheries Research Center's Marrowstone Marine Station. The approach will be coordinated with shipboard experiments testing a limited number of ballast water treatment hypotheses. Objectives Objective 1: Develop and refine experimental protocols and analysis techniques
Objective 2: Design and implement complementary ballast treatment experiments including:
Methodology The research team will evaluate and recommend (in consultation with project advisors and visiting scientists) various approaches to using remote sensors, particle counters, or genetic detection to measure treatment effectiveness at the shipboard scale. The objective is to identify approaches to assaying for organism viability, density and taxonomy (community composition) for a range of taxa that could be available specifically for ship-board testing. The team will review and critique potential detection methods and technologies that could be used to evaluate ballast treatment effectiveness for purposes of: 1) basic research; 2) shipboard monitoring/type approval of a treatment system against a standard (based on both particle size and percent removal); and 3) verification of ballast water exchange (BWE) at sea. Special attention will be given to "bottom line" type approval/compliance analysis against a standard. The team will identify currently available methods, and methods that could be made available with additional research. As needed, the team will propose novel sampling and detection approaches. "Real life" example applications, including upcoming evaluations of the UV system on residuals in the vessel M/T Aspiration in the no-ballast-on-board (NOBOB) condition will help focus the discussion. Toward this end, a five-day Ballast Discharge Monitoring Device Workshop will be convened to identify research methods and required detection instrumentation. The Workshop will also have policy relevance because the current and potential capabilities of various detection techniques play a major role in discussion of options for development of ballast treatment standards. Participation is sought from Singapore, Brazil, New Zealand and other nations directly involved in ballast water research. These experts will be consulted in advance regarding systems that they would like to see evaluated. The team will compile findings lessons learned regarding pilot and bench scale analysis, and will relate these to shipboard experience using the M/T Aspiration to identify potential efficiencies available in treatment evaluation through utilizing a multiscale approach.
Highlights and Key Findings This project was initiated in FY 2001 as a result of earlier collaboration by USGS with a stakeholder partnership. Initial meetings were convened at the Western Fisheries Research Center (WFRC) Seattle Laboratory on July 31, 2000, December 11, 2000, and February 5-6, 2001. A study plan was developed and peer reviewed in collaboration with a research team involving the University of Washington, Northeast Midwest Institute, Fisheries and Oceans Canada, State of Washington, and others. USGS is implementing the research program at the WFRC Marrowstone Island Marine Field Station, where USGS maintains a seawater wetlab for fisheries research. Initial instrumentation necessary for the project was purchased. To begin the research, WFRC developed a partnership with the Northeast Midwest Institute involving several researchers from the Pacific Northwest and the Institute's Great Lakes Ballast Technology Project team to address: 1. The extent to which UV is selective at inactivating ambient culturable microbial strains and the effects of UV on regrowth and community composition; 2. Doses of UV necessary to inactivate the most sensitive and most resilient culturable microbes within the ambient assemblage; 3. Applications of the PCR apparatus to ballast treatment effectiveness microbial studies; 4. The extent to which UV at known doses inactivates reproduction in zooplankton and phytoplankton; 5. Doses of UV necessary to inactivate the most sensitive and most resilient culturable plankton taxa within the ambient community. Progress so far:
Where Are We Headed In 2003 USGS and research partners will continue to examine the affect of UV treatment on the composition of marine microbial communities. Measurements will be made of the fatty acid composition of bacteria that could be cultured in the laboratory, as one evaluation approach. Work will consist of international collaboration on instrumentation/measurement methodology; additional bench scale dose/response studies for UV irradiation of zooplanktors; and preliminary shipboard trials of ballast water treatment technologies. The research objective is to determine not only the efficacy of the different treatment methods toward reducing the total number of viable microorganisms, but to determine if the treatment changes the composition of the microbial communities. Ultimately, the goal is to determine residual risk of species establishment in West Coast environments, following treatment. With this information, ballast water and environmental managers can develop treatments to reduce that risk to acceptable levels. Project Contact Lyman Thorsteinson Email: lyman_thorsteinson@usgs.gov Publications |
