The use of acoustic monitoring in the National Marine Fisheries Service marine mammal incidental take authorizations.

Under the Marine Mammal Protection Act (MMPA), the National Marine Fisheries Service (NMFS) is charged with conservation and management of marine mammals under NMFS’ jurisdiction. A regulatory mechanism is in place for NMFS to issue incidental take authorizations under the MMPA to operators whose activities may adversely affect marine mammals. As a mandate under the MMPA, mitigation and monitoring measures are prescribed to minimize any impacts on marine mammals and their habitat (prey species and acoustic environment) and to assess the degree of such impacts when such incidental take authorizations are issued. However, due to the limited visual range under and above water, monitoring measures using acoustical techniques are often required to supplement visual monitoring and to assist in making mitigation decisions. This presentation provides a summary of existing acoustic monitoring measures that are currently used in NMFS’ marine mammal incidental take authorizations; discusses the limitations, technical issues, practicality, and training needs involving acoustic monitoring; and highlights future needs in standardizing, improving, and expanding such techniques for more effective mitigation and monitoring measures.