01815nas a2200169   4500008004100000022001400041245006400055210006300119260001600182300001600198490000800214520130400222100001901526700003001545700001901575856005101594       2018                        eng d  a0001-496600aPredator-prey interactions in the Southern California Bight0 aPredatorprey interactions in the Southern California Bight  cJan-09-2018  a1921 - 19210 v1443 a<p>The Southern California Bight (SCB) is an important foraging area for a variety of cetacean species, including blue whales and beaked whales. However, the interactions of these species with their prey (krill and deep-water squid, respectively) can be very difficult to observe. Moorings combining passive and active acoustics were deployed at two locations in the SCB in two consecutive fall and winter seasons. A High-frequency Acoustic Recording Package sampling at 200 kHz recorded the full range of baleen and beaked whale signals. The active acoustic system on each mooring included two Simrad Wide Band Acoustic Transceivers (WBAT). A bottom-mounted WBAT had an upward looking 70 kHz transducer and the one at 300 m depth had upward looking 70 kHz and 200 kHz transducers. Over the course of four months, blue whale songs and social calls were recorded on both moorings. Beaked whale echolocation clicks were commonly detected on the mooring deployed offshore, with only rare beaked whale encounters on the coastal mooring. Backscatter data indicated overlap in the presence of cetacean predators and their prey. Scattering layer dynamics were dominated by regular diel migration, with differences in scatterer abundance between mooring sites, as well as on 2&ndash;5 day time scales.</p>
1 aŠirović, Ana1 aBaumann-Pickering, Simone1 aWarren, Joseph  uhttp://asa.scitation.org/doi/10.1121/1.5068414