Prediction of climate change effects of fish communities in the Mackinaw River watershed, Illinois, USA.

As part of an integrated assessment of multiple sector impacts produced by predicted changes in climate we have integrated a set of models, which provide predictions of fish populations under changing flow and temperature regimes. The core of the approach is the U. S. Fish and Wildlife Service Physical Habitat Simulation Model (PHABSIM). PHABSIM estimates habitat conditions based on flow, which are life stage specific. The output from PHABSIM is used to model fish populations, considering both flow and a temperature threshold, which affects spawning date. Water temperatures were modelled based on air temperature. The resulting assessment tool provides the means to evaluate the effect of multiple stressors produced by climate change scenarios. The model has been used to estimate smallmouth bass (Micropterus dolomieui) populations for representative reaches of the Mackinaw River, Illinois. The model has been used to illuminate population effects of changing flow and temperature under historical climate/weather conditions, as well as under climate change scenarios. The integrated models in the assessment tool have provided a useful addition to watershed management, improving our capacity to evaluate natural resources impact at temporal scales typical of climate change, and management response systems.

Selection of test methods to assess ecological effects of mixed aerosols.

Components of the mixed aerosols generated during military training are known to be of toxicological and/or ecological significance. There are few studies, however, quantifying mixed aerosol effects on ecosystems. Prompted by our finding that one or more of the compounds in the mixed aerosols commonly encountered in military training areas showed mutagenic effects in several species, a multiyear effort is evaluating the use of ecotoxicity testing methods to assess mixed aerosol ecological impacts. Selection of test methods for ecoepidemiology begins with the identification of the data required to meet defined environmental quality objectives. The data requirements are then matched with appropriate test methods, and testing results are related to important ecological effects resulting from aerosol exposure. The critical element of test system selection is to ensure that toxicity testing results relate to important ecological effects. The procedures developed for identifying test methods to assess mixed aerosols are also applicable to a range of environmental contaminants regulated by air, water, and solid waste regulations.