Integrating information on displacement caused by mid-frequency active sonar and measurements of prey field into a population consequences of disturbance model for beaked whales
Abstract
The objective of this project is to provide realistic predictions of the long-term effect of disturbance caused by medium-frequency active sonar (MFAS) on beaked whale populations at AUTEC and SCORE using the tools developed as part of ONR award N000141612858. In addition, we will use novel passive acoustic methods to quantify the distribution and abundance of beaked whale prey on AUTEC and SCORE in order to assess the potential role of this ecological driver in determining the populations responses to disturbance. The project has been divided into the following tasks. Task 1 quantification of beaked whale response to MFAS exposure: passive acoustic data from AUTEC and SCORE will provide start and stop times for MFAS use on both ranges, information on the location of beaked whale foraging groups, and a direct measure of sonar received level for these groups. This information will be combined with existing telemetry data to estimate risk functions for Cuvier s and Blainville s beaked whales, the number of foraging dives lost as a result of MFAS disturbance, and the extent of any MFAS-induced displacement. Task 2 development of bioenergetics-based PCoD models for beaked whales: we will develop dynamic energy budget (DEB) models for both beaked whale species and incorporate these into population models that account for the effect of individual energy intake on resource availability. These models will be used to investigate the likely effects of MFAS exposure on beaked whale health, life history and population structure. Task 3 quantification of beaked whale abundance and exposure as a function of MFAS operations on AUTEC and SCORE: daily estimates of beaked whale abundance within the hydrophone arrays at AUTEC and SCORE will be combined with information on the number, duration and timing of MFAS operations from operational logs and passive acoustic data to quantify levels of MFAS exposure on both ranges. Task 4 quantification of beaked whale prey distribution at AUTEC and SCORE: data collected by an autonomous undersea vehicle will be used to estimate the distribution of potential beaked whale prey on both ranges. Observed prey densities will be related to associated measures of habitat characteristics to estimate prey distributions outside the hydrophone arrays and assess the potential effects of displacement on beaked whale energy intake. Task 5 integration of model results for impact assessment: results from the other tasks will be incorporated into the DEB models and used to predict beaked whale population trajectories and population size structure under different disturbance scenarios and with different prey fields.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 04, 2018
- Source ID
- N000141812821
Entities
People
- John Harwood
Organizations
- Office of Naval Research
- United States Navy
- University of St Andrews