Successes and failures of acoustics in the measurement of environmental impacts

The use of hydroacoustics has grown in response to the need for more accurate information to manage fisheries. Parallel to its increasing importance to fisheries management has been the expansion of its use for environmental impact assessment. Applications of acoustic technology to estimate the vulnerability of fish to entrainment by cooling water intakes, irrigation drawdown, and turbine operations at hydroelectric dams have led to operational and engineering methods to minimize harmful effects on fish populations. In addition to reducing detrimental effects, the use of acoustics to estimate fish densities before and after underwater blasting operations has led to increasing work windows for bridge and harbor construction. The recent application of acoustics to measure nuisance growths of aquatic macrophytes in shallow, freshwater lakes is leading to techniques for quantitative assessment of fish habitat, which will be equal if not more important to environmental impact evaluations and fisheries management in the future. Successful applications of hydroacoustics to environmental impact assessment are primarily attributed to the researchers having the ingenuity to overcome common biological and engineering limitations, whereas, the failures are not.