IMIS

The waters off southern California are remarkably diverse and species rich, but they are also an area of swift commercial development, navy training activity, population growth and climate change. Continued visual marine mammal and seabird surveys working in concert with oceanographic ecosystem investigations are essential for monitoring the health and changes of the California current system. From July 2004 to April 2008 dedicated visual observers following consistent line-transect methods observed from the CalCOFI platforms on quarterly cruises. Observers used handheld 7X50 reticle Fujinon binoculars to sight, identify, and make school size estimates of cetaceans and pinnipeds encountered along the transect lines between CalCOFI water sampling stations. The southern water sampling stations are set along six, parallel lines running southwest to northeast, with lines increasing in length from north to south (470 - 700 km) and stations occurring every 37 km in coastal and continental shelf waters and every 74 km offshore. Three research vessels were used for the sixteen surveys, Scripps Institution of Oceanography Roger Revelle (2 surveys) and New Horizon (8 surveys) and, NOAA David Starr Jordan (6 surveys), vessel height varied from 8.1-13.2m and survey speed varied from 10 to 12 knots. Effort tracklines, two Delphinus delphis sightings in 2005 and one in 2006, overlap with data published in the CalCOFI and NMFS Seabird and Marine Mammal Observation Data, 1987-2006 dataset. However, data collected for this dataset used different methods and observers. Please contact the primary contact listed for more details.