Abstract
A cooperative effort between several Federal and State transportation and resource agencies along the west coast of the United States has recently resulted in the establishment of interim criteria for the onset of physical injury to fishes exposed to the underwater sounds generated by impact pile driving. The National Oceanic and Atmospheric Administration's National Marine Fisheries Service (NOAA Fisheries), in its administration of the Endangered Species Act (ESA) and the essential fish habitat provisions of the Magnuson-Stevens Fishery Conservation and Management Act (MSA), is using these criteria to assess potential impacts to its trust resources during consultation with Federal agencies on projects that include pile driving in, or near, aquatic environments. The new criteria use two metrics – peak sound pressure level (SPL) and sound exposure level (SEL). For the purpose of these consultations, and until new information becomes available to refine the criteria, the onset of physical injury would be expected if either the peak SPL exceeds 206 dB (re: 1 µPa)) or the SEL, accumulated over all pile strikes generally occurring within a single day, exceeds 187 dB (re: 1 µPa 2 • sec) for fishes 2 grams or larger, or 183 dB for smaller fishes. Here we present how NOAA Fisheries uses these criteria to assess the risk to fishes that are listed under the ESA or the essential fish habitat managed under the MSA.