| Bioacoustics Activities |
| Passive Acoustic Monitoring: Using technology from the Bioacoustics Laboratory at Cornell University, we developed and tested a bottom-mounted autonomous passive acoustic system for monitoring bioacoustics (a core IOOS variable) in the Monterey Bay study area. Low frequency sound has been shown to be particularly useful in tracking the abundance of apex predators such as large whales. |
| The system consists of an array continuously recording passive hydrophone system mounted on a mooring. Previous studies have shown that whale vocal behavior is an accurate index of whale abundance, and a pilot study conducted in Monterey Bay in 2000 demonstrated that this tool can be used to correlate whale abundance patterns with biotic and abiotic factors. |
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Blue whale abundance in Monterey Bay as measured using passive acoustics 2004 - 2005. |
| We deployed this acoustic array in 2004, and now are collecting information on the abundance (Figure 8) and location (Figure 9) of endangered whales in Monterey Bay. By adding this new and innovative way to monitor apex predator populations (through sound), we have greatly expand the temporal resolution of the CIMT Monterey Bay marine mammal data set. In addition, this system provides a continuous record of vessel traffic and human-produced low frequency sound in the study area and thus will establish a reliable near-shore acoustic monitoring system in the nearshore coastal zone. |
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Locations of blue whale songs as measured using passive acoustic array. Note concentration of animals at edge of the Monterey Submarine Canyon near sources of loud, human-produced broad-band sound source in Monterey Bay July 7, 2004 |
