Cetaceans, pinnipeds, and humans: Monitoring marine mammals in the Arctic and characterizing their acoustic spaces
Abstract
As ocean temperatures, currents, and prey availability are altered by climate change, changes in marine mammal species composition, abundance, and distribution are expected. In addition, the observed northward retreat of the minimum extent of summer sea ice is creating opportunities for expansion of industrial development and maritime transporation into previously closed seasons and localities in the Alaskan Arctic, in turn increasing the levels of ambient noise and other environmental stressors. Knowledge of the timing and location of marine mammals remains an important role in assessing where, when, and how anthropogenic activities may be conducted to mitigate the impact on protected species. Contemporary information on marine mammal spatio-temporal distribution is therefore critical; reliance on historical data could lead to poor management decisions affecting not only the species in question, but also the native peoples who rely on them for subsistence. Information on these broadly dispersed, upper trophic level species is also needed to accurately model top-down control in Arctic ecosystems. Long-term passive-acoustic moorings remain the only means available for collection of year-round data on the spatio-temporal occurrence of multiple marine mammal species as well as environmental and anthropogenic noise sources. They also provide the only data that can be used to characterize the acoustic environment of these species; understanding the temporal baseline trends in these acoustics environments can help determine the extent of future noise impacts from anthropogenic and climate-driven sources. Our decade-long array, extending from the Aleution Islands to the Chukchi Plateau and Cape Halkett in the Arctic (and with over half the moorings co-located with biophysical instrumentation) provides the longest and most-extensive integrated time-series of calibrated acoustic recordings and oceanographic measurements in Alaskan waters. Analyses have been completed, and as a result trends can be described for the presence of eleven species of Arctic and subarctic cetaceans and pinnipeds, plus ice, vessel, and airgun noise over the period from 2007 through 2016; noise level analyses and the investigation of marine mammal presence with biophysical parameters are ongoing. These moorings have also been deployed in locations with widely varying ambient noise levels, providing the opportunity to characterize adn compare the background noise conditions and describe the main biotic, abiotic, and anthropogenic contributors to the acoustic environment for each season, at whichever locations and time frames are of interest. As additional year of data are added, they can be compared with, and then incorporated into, these long-term trends. Here, we propose to analyze passive acoustic data for marine mammal presence and ambient noise levels to characterize the acoustic environment of marine mammals in the Alaskan Arctic from 2016 through 2019. We also propose to redeploy the full set of twenty recorders to maintain the long-term time series in these locations during this period of rapid environmental change.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 04, 2018
- Source ID
- N000141812792
Entities
People
- Nicholas Bond
Organizations
- Office of Naval Research
- United States Navy
- University of Washington