PICEAS (Pacific Islands Cetacean Ecosystem Assessment Survey) 2005 was an ecosystem survey in the U.S. Exclusive Economic Zone (EEZ) waters of Palmyra and Johnston Atoll and adjacent waters south of Hawaii where Hawaiian long-line fishing occurs.
The Southwest Fisheries Science Center (SWFSC) has conducted a variety of marine mammal surveys in the eastern tropical Pacific (ETP) and other areas of the Pacific Ocean. The purpose of these surveys has been to estimate cetacean population sizes and to monitor the impact of incidental kill due to commercial fisheries, particularly the tropical purse-seine fishery for yellowfin and skipjack tuna. The northern stock of common dolphin, Delphinus delphis, is taken in the purse-seine tuna fishery (Hall and Lennert 1994). The index of relative abundance for this stock computed from sightings on tuna vessels has declined substantially in the last decade (Anganuzzi and Buckland 1994). However, because tuna vessels cover only the southern portion of the stock’s range, the declines in the index may be due to a northward shift in distribution, rather than an actual decline in abundance. There has been an increase in abundance of tropical delphinids and a decrease in abundance of temperate delphinids during this period in California waters, accompanied by a general warming trend in ocean temperature (Barlow, 1993). Previous research vessel surveys have covered either northern (Hill and Barlow 1992) or southern (Wade and Gerrodette 1993) parts of the range of the northern common dolphin, but neither of these surveys have covered the middle portion of the range off the coast of northern Baja California. The 1993 survey was designed to produce the first range-wide estimates of abundance for the northern common dolphin and its recently described congener, Delphinus capensis (Heyning and Perrin, 1994) . The 1993 survey was conducted by the NOAA Ships McArthur and David Starr Jordan.
In 1986 the U.S. National Marine Fisheries Service (NMFS) initiated a long-term, large-scale research program to monitor trends in the abundance of dolphin populations in the eastern tropical Pacific (ETP).
This project was part of a larger international project (SPLASH) designed to estimate the abundance and determine the population structure for humpback whales throughout the North Pacific involving the governments of Canada and Mexico as well as multiple agencies within the government of the U.S. The primary study methods were photo-identification and biopsy sampling. Passive acoustics were used to aid in finding aggregations of whales. In addition, biological and oceanographic data were collected to better characterize the whale’s environment, and survey data were collected for all other cetacean and pinniped species observed. Biopsy samples were also taken from other cetacean species, primarily in areas where they have been poorly sampled in the past. The Hawaiian Island Humpback Whale Sanctuary (HIHWS) collaborated on this cruise by sending two skilled photographers on each leg of survey effort. The U.S. Navy collaborated on this cruise by funding the acoustic and oceanographic sampling.
The CSCAPE 2005 cruise was a collaboration between the National Marine Fisheries Service (NMFS) and the National Marine Sanctuary (NMS) Program to assess the abundance and distribution of marine mammals and to characterize the pelagic ecosystem off the U.S. West Coast.
This survey focused on two species of common dolphin: the short-beaked common dolphin, Delphinus delphis, and the long-beaked common dolphin, Delphinus capensis , off southern California, USA and Baja California, Mexico.
The California Current Cetacean and Ecosystem Assessment Survey (CalCurCEAS) is a marine mammal assessment survey of the U.S. West Coast waters. Similar research in this geographic area was conducted under the name of ORCAWALE (for Oregon, California, and Washington Line-transect Experiment) in previous years.
This study was conducted in Mexico aboard the National Oceanographic and Atmospheric Administration (NOAA) research ship McArthur during two months in summer/fall 1995. The primary purpose of this research was to learn how to better estimate the abundance of long-diving whales during ship line-transect surveys. These whale species, including beaked whales and dwarf and pygmy sperm whales, dive for such long periods of time that there is a high probability that they will never surface within the visual range of observers searching from a moving survey vessel with 25X binoculars. The project was called CADDIS (Cetacean Acoustic Detection and Dive Interval Studies) and focused on two potential approaches to improve abundance estimates: 1) acoustic detection of diving animals, and 2) collecting dive interval data on those species to serve as a basis for a model-based abundance correction factor. The CADDIS research was conducted primarily in the southern Gulf of California, Mexico. This area was chosen for two main reasons: prior surveys showed the area to have a very high density of small long-diving whales of the genera Mesoplodon, Ziphius and Kogia (Mangels and Gerrodette 1994), and the area has consistently calm seas which enables dive intervals to be observed and accurately measured. The timing of the survey was similarly chosen as the season with the consistently lowest winds in the southern Gulf.