Accession Number:

ADA361229

Title:

Magellan II LFAl5

Descriptive Note:

Final rept. 30 Apr 96-31 MAy 97

Corporate Author:

CORNELL UNIV ITHACA NY

Personal Author(s):

Report Date:

1999-03-01

Pagination or Media Count:

6.0

Abstract:

Acoustic data from a horizontal line array deployed from the RV Cory Chouest were analyzed for marine mammal sounds in order to assess the accuracy of Navy personnel in detecting and identifying whale vocalizations, and to determine whether there was any evidence of potential impact on whales from SURTASS LFA transmissions. Results were based on an analysis of 386 hours from the LFA-15 exercise, February and March 1996. Detection and identification of blue whale signals was poor in both months, while good for fin whales. Errors had little or no impact on compliance because most of the whale calls that were missed were probably from distant animals. Whale acoustic detections were converted into probability of detection statistics with appropriate confidence intervals, and detection probabilities were compared between the LFA-on and LFA-off conditions. The data provide some evidence that whales are less likely to call when the SURTASS-LFA is transmitting. However, the data for this set of circumstances are too sparse to make an accurate assessment of impact. In order to accurately assess the effects of SURTASS-LFA transmissions on whale call probability, transmissions need to be turned off on a more regular basis for periods of 1 hour or longer.

Subject Categories:

  • Biology
  • Acoustic Detection and Detectors
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE