Reports - California Cooperative Oceanic Fisheries Investigations

STATE OF THE CALIFORNIA CURRENT
CalCOFI Rep., Vol. 47, 2006
ratory, zooplankton are enumerated by species and developmental
stage, and biomass is calculated by multiplying
counts (units of number per cubic meter) by weights
of individuals (mostly from literature values). Waters out
to 85 miles offshore of Newport were sampled in May
2005. Temperature anomalies along the Newport line
are based on the Smith et al. (2001) climatology.
Cruises to sample pelagic fish typically sample every
ten days from mid-April through mid-July. Since 1998,
pelagic forage and predatory fish have been sampled
at night with a pelagic rope trawl (NET Systems 244, 20
× 30 m mouth, 100 m in length; mesh size ranges from
163 cm near the throat of the trawl to 8.9 cm in the cod
end; a 6 m long section of 0.8 cm mesh lines the cod
end). Trawls are typically 30 minutes in duration, sampling
from the surface down to a depth of 20 m. Four
stations are sampled along each of two transect lines in
shelf waters off Columbia River and Willapa Bay, Washington
(for station locations see Emmett et al. 2005).
Regional Analyses—Central California
The Monterey Bay region time series consists of two
moored telemetering buoys located in the Bay, hydrographic
surveys of the Bay every three weeks, and quarterly
surveys along CalCOFI Lines 60 and 67 from the
coast out to station 90. Stations are sampled to near bottom
or 1012 m where water depth permits. Parameters
measured are similar to those for the CalCOFI program
(described below), and methods are described more fully
in Chavez et al. (2002). Properties are mapped for each
32
Figure 1. Location of CalCOFI stations.
section and can be viewed at http://www.mbari.org/
bog/projects/secret/default.htm.
The Fishery Ecology Division of the Southwest Fishery
Science Center has conducted a standardized midwater
trawl survey during May–June aboard the NOAA
R/V David Starr Jordan every year since 1983. Historically,
the survey was conducted between 36˚30'–38˚20'N
latitude (Carmel to Bodega Bay, California), but starting
in 2003, coverage has expanded to effectively sample
the entire coast of California. The primary purpose
of the survey is to estimate the abundance of pelagic
juvenile rockfishes (Sebastes spp.) and to develop indices
of year-class strength for use in groundfish stock assessments
on the U.S. West Coast.
Regional Analyses—Southern California
The CalCOFI program conducts quarterly surveys
off Southern California, covering 66 stations (fig. 1).
Although surveys began in 1949, this pattern was adopted
in 1984. CTD/Rosette casts to a depth of 525 m are
equipped with sensors for conductivity, temperature,
pressure, oxygen, fluorescence, and light transmission.
Salinity, dissolved oxygen, nutrients, and chlorophyll are
determined on 12 to 20 water samples collected throughout
the water column. Standard (505 µm mesh) oblique
bongo tows are conducted to 210 m depth at each station,
bottom depth permitting. Detailed descriptions of
sampling and analytical protocols and data reports from
past cruises are archived on the CalCOFI Web site
(http://www.calcofi.org).