Behavioral responses of individual blue whales (Balaenoptera musculus) to mid-frequency military sonar
-
2019
-
Details
-
Journal Title:Journal of Experimental Biology
-
Personal Author:
-
NOAA Program & Office:
-
Description:This study measured the degree of behavioral responses in blue whales (Balaenoptera musculus) to controlled noise exposure off the southern California coast. High-resolution movement and passive acoustic data were obtained from non-invasive archival tags (n=42) whereas surface positions were obtained with visual focal follows. Controlled exposure experiments (CEEs) were used to obtain direct behavioral measurements before, during and after simulated and operational military mid-frequency active sonar (MFAS), pseudorandom noise (PRN) and controls (no noise exposure). For a subset of deep-feeding animals (n=21), active acoustic measurements of prey were obtained and used as contextual covariates in response analyses. To investigate potential behavioral changes within individuals as a function of controlled noise exposure conditions, two parallel analyses of time-series data for selected behavioral parameters (e.g. diving, horizontal movement and feeding) were conducted. This included expert scoring of responses according to a specified behavioral severity rating paradigm and quantitative change-point analyses using Mahalanobis distance statistics. Both methods identified clear changes in some conditions. More than 50% of blue whales in deep-feeding states responded during CEEs, whereas no changes in behavior were identified in shallow-feeding blue whales. Overall, responses were generally brief, of low to moderate severity, and highly dependent on exposure context such as behavioral state, source-to-whale horizontal range and prey availability. Response probability did not follow a simple exposure–response model based on received exposure level. These results, in combination with additional analytical methods to investigate different aspects of potential responses within and among individuals, provide a comprehensive evaluation of how free-ranging blue whales responded to mid-frequency military sonar.
-
Keywords:
-
Source:Journal of Experimental Biology, 222(5)
-
DOI:
-
ISSN:1477-9145 ; 0022-0949
-
Format:
-
Publisher:
-
Document Type:
-
Rights Information:Other
-
Compliance:Library
-
Main Document Checksum:urn:sha-512:2acbe46ded831108e712236f74cb6ef65c59ab05f254c7a8d69c3a0180061c6d53d96ddab79c6092d6f1b346055f4207bb926a45742e00af9243cb1fca67b148
-
Download URL:
-
File Type:
ON THIS PAGE
The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles,
guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners. As a repository, the
NOAA IR retains documents in their original published format to ensure public access to scientific information.
You May Also Like
COLLECTION
National Marine Fisheries Service (NMFS)