Near Shore Biological Coupling
A program of fieldwork was carried out at Peregian Beach, Australia in collaboration with the University of Queensland (UQ). This was a Pilot Study concerned with the setting to work of a system for passive acoustic and visual tracking of whales, as well as collecting acoustic and remotely observed behavioral data to provide the baseline information of the undisturbed ‘normal’ behavior of the whales during migration along the east coast of Australia.
Unanswered questions include how these animals use vocalizations for communication and maintaining their behavioral repertoire, and how this may be influenced by the ambient noise field. The biological significance of sounds produced by individuals is not well understood and little is known about the context and perception of acoustic signals. The effects of anthropogenic sound sources on the whales via interaction with the natural ambient noise field are thought to be important, however understanding this requires an understanding of the whales’ use of sound under ‘normal’ (undisturbed) conditions.
The Humpback Whale Acoustic Research Collaboration (HARC) is a collaborative project between researchers at the Scripps Institution of Oceanography (SIO), the Woods Hole Oceanographic Institution (WHOI), Australia’s Defence Science and Technology Organization (DSTO), and the University of Queensland (UQ). This collaborative project will study the behavior of humpback whales, on the east coast of Australia, in the presence and absence of anthropogenic sources (from shipping noise and experimental playback), as well as with variations in a natural ambient noise field, including surf and wave-induced noise, along known migratory pathways.
An underlying hypothesis is that the influence of sounds on the whales’ behavior can be assessed by detailed observations in the presence and absence of the sound. However to do so requires an accurate assessment of the noise field at the whale’s location, an understanding of the physical oceanographic environment and a means of making detailed observations of responses. A variety of instrumentation, including digital-recording animal tags, visual and acoustic tracking, and propagation modeling of the acoustic surroundings will be used.
The Australia investigators have an ongoing research program on humpback whale vocalizations with yearly records of song data extending back 20 years and acoustic and visual tracking with behavioral observations in 1996 and 1997. Other workers in east Australian waters have built up an extensive photo identification catalogues of the stock of migrating humpback whales, and there have been successful biopsy projects on the same stock.
The SIO and WHOI components leverage on the Australian investigators’ planned experiments and each other to generate a greater understanding of whale response to noise than could be accomplished by any individual program alone.