Watch the interview with Dr. Kelly Benoit-Bird
Download the Benoit-Bird interview transcript (PDF)
About Dr. Benoit-Bird
Dr. Kelly Benoit-Bird is a Senior Scientist at the Monterey Bay Aquarium Research Institute. Dr. Benoit-Bird’s research uses underwater sound to observe how animals ranging in size from nearly microscopic zooplankton to sperm whales interact with each other and their underwater environment. A major focus of what Kelly studies is predator-prey interactions. For example, some recent projects have examined Hawaiian spinner dolphins foraging on deep sea fish, squid feeding on fish and krill, and sardines feeding on copepods. As part of this work, she studies how the amount of prey and where it is located changes with time and the ways animals cope with this variability. Dr. Benoit-Bird is using both passive acoustics and active acoustics, along with photography and net trawls, to study a range of interactions between animals in the ocean.
Foraging Behavior Research
Dr. Benoit-Bird uses underwater sound to observe the foraging behavior of spinner dolphins and benthic fish. Off the islands of Hawaii, spinner dolphins and benthic fish feed on the mesopelagic boundary community. The mesopelagic boundary community is a group (“community”) of small fishes, shrimps, and squids that live in the middle of the water column (“mesopelagic”) and near islands (“boundary”). . The mesopelagic boundary community moves both vertically (up and down in the water column) and horizontally (inshore and offshore) each day. Using sonar, Dr. Benoit-Bird observed the movements of both the prey and the predators at the same time. Dr. Benoit-Bird showed that the daily movements of the spinner dolphins corresponded with the vertical and horizontal movement of the boundary community.
The figure above illustrates the daily horizontal movement of the mesopelagic boundary community. The mesopelagic boundary community is found offshore at deep depths (400-700 m) during the day and within 0.5 km of the shore and at shallow depths (0-400 m) at night. The spinner dolphins move offshore at dusk to feed on the mesopelagic boundary community as it rises to shallower depths. They follow the prey as it moves inshore during the night, and follow it offshore after midnight. The spinner dolphins then return to nearshore waters to rest during the day.