Cetaceans Surveyed in the EEZ of Palmyra Atoll

A primary research objective of the PIFSC Cetacean Research Program is to assess the abundance, distribution, and stock structure of whales and dolphins across the Pacific Islands Region and adjoining high seas. In pursuit of this goal, PIFSC scientists and colleagues from the Southwest Fisheries Science Center are collaborating in a study of cetaceans in the 200-nm U.S. Exclusive Economic Zone (EEZ) around Palmyra Atoll. The Palmyra Cetacean and Ecosystem Assessment Survey, or PICEAS, entails a pair of research cruises using the NOAA Ship Oscar Elton Sette. The first cruise leg was carried out from October 20 to November 18, 2011. It involved a large-scale visual and acoustic line-transect survey of cetaceans within the Palmyra EEZ. Data from the survey will enable updated estimates of abundance for all cetaceans in this region. The most recent survey to encompass the entire EEZ of Palmyra was in 2005.

During the October-November 2011 PICEAS cruise, scientists on the NOAA Ship Oscar Elton Sette documented sightings of whales and 
                 dolphins in waters around Palmyra Atoll and Kingman Reef.  As illustrated in this photo, biological observations were also made at 
                 close-range, using a small boat launched from the Sette.
During the October-November 2011 PICEAS cruise, scientists on the NOAA Ship Oscar Elton Sette documented sightings of whales and dolphins in waters around Palmyra Atoll and Kingman Reef. As illustrated in this photo, biological observations were also made at close-range, using a small boat launched from the Sette.

In the 2011 survey, transect lines were selected to cover waters within the EEZ around Palmyra Atoll uniformly. Poor weather and low cetacean densities resulted in few sightings of cetaceans during the 30 day expedition; however, two sightings of false killer whales were recorded, providing a great opportunity to field test a new protocol designed to better understand how false killer whale behavior affects the applicability of standard survey methods to assess this species. Additional survey effort was devoted to nearshore waters around Palmyra and Kingman Reef, resulting in several sightings of island-associated melon-headed whales, bottlenose dolphins, and spinner dolphins. A High-Frequency Acoustic Recording Package (HARP) was deployed on the seafloor at Kingman Reef to record sounds produced by cetaceans and other biota in the neighborhood of the HARP over several months. Analysis of the sounds will help us assess the seasonality of island-associated populations and the connectivity between cetaceans living around Kingman and Palmyra.

The second survey leg of PICEAS will be conducted in the Palmyra study area from late April through mid-May, 2012. The data from both cruises will be combined in an analysis of cetacean abundance.