Index of visual monitoring efforts, weather conditions and position updates from CalCOFI cruises in the California Current System, 2008 - 2009. This dataset has been superseded by knb-lter-cce.262.

Field observations are carried out to gain understanding of cetacean ecology and habitat. Visual monitoring for cetaceans has been conducted on quarterly CalCOFI cruises since July 2004 using standard line-transect protocol (Burnham et al. 1980;Buckland et al. 1993; Barlow 1995). Visual observers watch during daylight hours, when weather permits (Beaufort sea states 0 to 5 and visibility greater than 1 nautical mile) and while the ship transits between CalCOFI stations.