MP8 Control and Regulation of Non-indigenous Species
A105 & A106
1:20 PM - 4:40 PM, Monday
() How risky is it? Comparing the risk reduction of nonindigenous species due to biocide treatment of ballast water with the potential for environmental harm.
Sano, L1, Landrum, P2, 1 University of Michigan, Ann Arbor, MI, USA2 Great Lakes Environmental Research Laboratory, NOAA, Ann Arbor, MI, USA
ABSTRACT- The introduction of nonindigenous aquatic species (NIS) through the release of ballast water constitutes one of the greatest threats to aquatic ecosystems worldwide. To help address this issue, the International Maritime Organization issued guidelines in 2004 for ballast water management technologies. One of the conditions set forth is that proposed treatment technology not cause more, or greater, environmental impacts than it solves. This standard is particularly relevant for chemical biocides, especially if active residuals are discharged into receiving water. In order to assess these risks, this study employs a qualitative risk tradeoff framework to evaluate the risks of NIS (i.e., the "target risk" sensu Gray and Graham 1995) compared to the risks associated with the release of biocide residual (i.e., the "countervailing risk"). This framework is applied to overseas, unballasted vessels trading on the Laurentian Great Lakes. Because these vessels comprise the majority of overseas traffic into the Great Lakes and because they are not subject to ballast water management, they constitute the largest current threat for the introduction of additional NIS. Several different elements of the target and countervailing risk will be assessed including the potential magnitude and spatial extent of effects, the types of organisms and populations affected, and the level of certainty of impacts. For the target risk, the impacts of current NIS in the Great Lakes will be considered in addition to the likelihood of future invaders. This information will be compared with data from laboratory bioassays and a ecosystem-level effects model for the candidate biocide, glutaraldehyde. The results from this analysis should provide a framework for evaluating chemical treatment technologies both in the Great Lakes and in other maritime ports.
Key words: ballast water treatment, nonindigenous species, risk tradeoff analysis, Great Lakes