데이터셋 상세
미국
Southeast Alaska cetacean vessel surveys conducted by Alaska Fisheries Science Center, National Marine Mammals Laboratory from 1991-04-20 to 2012-07-20 (NCEI Accession 0140931)
In 1991, NMML initiated cetacean studies with vessel coverage throughout inland waters of Southeast Alaska. Between 1991 and 1993, line-transect methodology was used to: 1) obtain population estimates of both harbor porpoise and Dalls porpoise, 2) establish a baseline for detecting trends in porpoise abundance, and 3) define porpoise distributional patterns and seasonality. Three line-transect surveys were carried out each year spanning spring, summer, and fall. To update abundance and trends for both harbor porpoise and Dalls porpoise, NMML once again initiated line-transect surveys in 2006 (spring and summer), 2007 (spring, summer and fall), 2010 (summer and fall), 2011 (summer and fall), and 2012 (summer) using methods comparable to those used in the early 1990s.
데이터 정보
연관 데이터
Cetacean line-transect survey conducted in the eastern Bering Sea shelf by Alaska Fisheries Science Center, National Marine Mammal Laboratory from NOAA Ship Miller Freeman from 1999-07-07 to 2004-06-30 (NCEI Accession 0131862)
공공데이터포털
Visual surveys for cetaceans were conducted on the eastern Bering Sea shelf along transect lines, in association with the AFSC’s echo integration trawl surveys for walleye pollock. Surveys in 2000 and 2004 were from early June to early July, the survey in 2002 was from early June to late July, and the survey in 1999 was from early July to early August. Searches for cetaceans were conducted from the flying bridge of NOAA Ship Miller Freeman at a platform height of 12 m above the sea surface and survey speed of 18.5 22.0 km/h (10 12 kts). North south transect lines were spaced 37 km apart and defined by the historical acoustic survey for walleye pollock. Insufficient funding precluded including cetacean observers on all legs except in 2002. See Friday et al. 2012. Cetacean distribution and abundance in relation to oceanographic domains on the eastern Bering Sea shelf: 1999-2004 (http://www.sciencedirect.com/science/article/pii/S0967064512000100).
Small cetacean aerial survey conducted in Alaskan waters by Alaska Fisheries Science Center, National Marine Mammal Laboratory from 1997-05-08 to 1999-07-04 (NCEI Accession 0131991)
공공데이터포털
Aerial surveys were conducted to produce abundance estimates for the three Alaska stocks of harbor porpoise. Surveys occurred from May to July 1997 for the Southeast Alaska stock, May to July 1998 for the Gulf of Alaska stock, and June to July 1999 for the Bering Sea stock. Two primary observers observed from bubble windows on the left and right side of the plane. A belly window observer with a view directly down along the trackline collected sightings that were matched to the side observers and used to estimate a correction factor for perception bias that was specific to harbor porpoise in Alaskan waters.
Marine mammals line-transect survey conducted in the Gulf of Alaska from 2003-06-27 to 2003-07-15 (NCEI Accession 0130075)
공공데이터포털
Three marine mammal observers participated on a cetacean survey from 26 June to 15 July 2003, aboard NOAA Ship Miller Freeman as a piggyback project during a RACE acoustic-trawl survey for pollock (see RACE's Midwater Assessment and Conservation Engineering report here: http://www.afsc.noaa.gov/Quarterly/jas2003/divrptsRACE2.htm). A total of 2,242 km of trackline were surveyed with 364 cetacean sightings (1,079 individuals). An additional 28 cetacean sightings were made (175 individuals) during off effort periods. Species included harbor porpoise, Dall's porpoise, Pacific white-sided dolphins, killer whales, minke whales, fin whales, humpback whales, sperm whales, Baird's beaked whales, and Cuvier's beaked whales. See link for details: http://www.afsc.noaa.gov/Quarterly/jas2003/divrptsNMML2.htm.
목록