CalCOFI marine mammal surveys 2004-2008 - on effort

Annie B. Douglas, Cascadia Research

From July 2004 to April 2008 dedicated visual observers following consistent line-transect methods (Buckland et al., 1993; Kinzey et al., 2003) 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.

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.

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.

Overview

This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downloadable online. Other attributes may be obtained upon provider's permission.

Attributes in dataset

Attribute (table column)	Description
oid	Unique ID number (generated by OBIS-SEAMAP)
recnum	Record number
year	Year of observation
season	Season of observation
linetype	Line type
cruise	Cruise ID
obs_date	Observed date
obs_time	Observed time
dattime	Observed date and time
sightnum	Sight number
oneffort	On effort
ontransect	On Transect
latitude	Latitude of observation
longitude	Longitude of observation
obs_count	Observed count (estimate)
calf	Number of calves
sp_obs	Species observed
spgroup	Species group observed
angle	Angle of observation
dis	Distance of observation
sp_tsn	Species ITIS TSN