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Killer Whale Vocal Response to Vessel Traffic

Killer Whale Vocal Response to Vessel Traffic. Celia Barroso Beam Reach Marine Science and Sustainability School Fall 2005 California State University, Long Beach Long Beach, California. Southern resident killer whales (SRKW) declared “depleted” under the Marine Mammal Protection Act

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Killer Whale Vocal Response to Vessel Traffic

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  1. Killer Whale Vocal Response to Vessel Traffic Celia Barroso Beam Reach Marine Science and Sustainability School Fall 2005 California State University, Long Beach Long Beach, California

  2. Southern resident killer whales (SRKW) declared “depleted” under the Marine Mammal Protection Act • Possible causes according to NOAA/NMFS Conservation Plan: • Pollutants/Contaminants (c.f. PCB, DDT) • Decreased prey availability • Anthropogenic noise pollution

  3. Population Structure and Communication • Different pods (J-pod, K-pod, and L-pod) • Different dialects • Pod specific calls (Ford, 1990) • S1 (J-pod, K-pod) • S16 (K-pod, L-pod) • S19 (L-pod) • Dominant calls

  4. Research that sparked my curiosity • Vessel traffic has increased five fold over between 1990 and 2000 (Foote et. al., 2004) • During the period of 2001-2003 all pods exhibited a significant (15%) increase in call duration in the presence of whale-watching vessels.

  5. My questions • Do SRKWs exhibit short-term changes in call duration in response to daily exposure to vessel noise? • Do they modify their calls to avoid masking by boat noise? • Examples: motor , ship , quiet

  6. How did I conduct my experiment? • I attempted to recreate Andrew Foote’s and Richard Osbourne’s published research over a shorter time scale. • We used a hydrophone, amplifier and digital recorder to receive and record the sounds. • Viewed spectrograms of S1, S16, and S19

  7. How did I conduct my experiment? • Calculated call duration of the second harmonics for S1 and S16 calls, the third harmonic for S19 high frequency component and fundamental for low frequency component S1 S19 Low S19 High S16

  8. What did I find? • The mean I calculated for S16 calls compares to the mean S16 call published by Foote et. al. • I did not record S16 or S19 calls that were quantifiable using my methods when vessels were absent

  9. What did I find? • Average S1 call duration in the presence of vessels is 1.17s and 1.105s in the absence of vessel noise.

  10. What did I find? • No trends

  11. Problems and conclusions • I, unlike Foote et al., was generally unable to distinguish which pod I was listening to • More observations are needed • Observations during peak whale-watching season • 24hr observations • Observations regarding activities and call duration • Perhaps SRKWs don’t modify their calls in response to vessel noise

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