Second Leg of the Palmyra Cetacean and Ecosystem Survey Underway

April 23, 2012
During the cruise, scientists on the NOAA Ship Oscar Elton Sette will document sightings of whales and 
                 dolphins in waters around Palmyra Atoll and Kingman Reef.  As illustrated in this photo, biological observations will also be made at 
                 close-range, using a small boat launched from the Sette.
During the cruise, scientists on the NOAA Ship Oscar Elton Sette will document sightings of whales and dolphins in waters around Palmyra Atoll and Kingman Reef. As illustrated in this photo, biological observations will also be made at close-range, using a small boat launched from the Sette.

The NOAA Ship Oscar Elton Sette is now engaged in the Palmyra Cetacean and Ecosystem Survey (PICEAS), a marine mammal assessment survey of waters around Palmyra Atoll extending offshore to the limits of the U.S. EEZ. The overall objective of the cruise is to estimate the abundance and understand the distribution of the dolphin and whale species commonly found around Palmyra Atoll.

The multidisciplinary PICEAS project involves two separate research cruise legs of the Sette. The first leg was completed in October-November, 2011. The second leg will be conducted from 23 April-17 May, 2012. The ship departed from Pago Pago, American Samoa to transit to the Palmyra study area. The scientific field party, consisting primarily of scientists from the NOAA Pacific Islands Fisheries Science Center (PIFSC) and Southwest Fisheries Science Center, will work in the area for 15 days before returning to the ship's home port in Honolulu, HI. Chief Scientist for the expedition is PIFSC biologist Dr. Erin Oleson.

The cruise plan for PICEAS Leg II calls for surveying cetaceans along designated transect lines, shown here in green.  The 
                 dark grey lines show survey tracks from PICEAS Leg I, completed during October–November 2011.
The cruise plan for PICEAS Leg II calls for surveying cetaceans along designated transect lines, shown here in green. The dark grey lines show survey tracks from PICEAS Leg I, completed during October–November 2011.

During the cruise, the research team on the Sette will conduct visual and acoustic surveys of cetaceans along predetermined transects - a so-called "line transect survey". The data collected will provide information on cetacean density, distribution, school size, and school composition, and together will be used to estimate cetacean abundance. Skin biopsies of cetaceans will be collected to provide a database for studies of stock structure and phylogenetic relationships. Photographs taken by the scientists will document geographic variation in dolphin morphology and pigment patterns and the distribution of individual large whales. Along with the cetacean observations, oceanographic data will be collected to characterize cetacean habitat and its variation over time. Data on the distribution and abundance of seabirds will be recorded to further characterize the ecosystem in which the cetaceans live.

During the PICEAS expedition, a focused effort of photo-identification and biopsy sampling will be made around Palmyra Atoll and Kingman Reef using a small boat launched from the Sette. Species such as melon-headed whales, bottlenose dolphins, spinner dolphins, killer whales, and beaked whales are known to occur at Palmyra Atoll. Some species are found there year-round while others are seen only occasionally. Less is known about the species occurrence at Kingman Reef. In order to investigate this further, a High-frequency Acoustic Recording Package (HARP) placed on the seafloor during the first leg of the PICEAS study will be retrieved. Data recorded by the HARP since its deployment in November will provide a record of all sounds in surrounding waters, including cetacean vocalizations. From these recordings we will be able to assess the diurnal and seasonal occurrences of cetacean species at Kingman Reef.