The technical requirements for this tow were: Descent rate of 50
meters per minute, ascent rate of 20 meters per minute. All tows
with ascending wire angles lower than 38° or higher than 51° in the
final 100 meters of wire were repeated. Additionally, a 45° wire
angle was closely maintained during the ascent and descent of the
net frame. Contents of the starboard side net were preserved in
buffered formalin for later identification. The port side net
contents were preserved in buffered ethanol for later
identification of ichthyoplankton and DNA studies for stations at
and inshore of station 70.
c. A Manta net (surface) tow, using a 505 :m mesh net on a frame
with a mouth area of 0.1333 m². The duration of each tow is 15
minutes at approximately 1½ knots.
d. Weather observations.
e. A Pairovet (vertical) plankton tow was taken at all stations
inshore of, and including station 70. The Pairovet net was fished
from 70 meters (depth permitting) to the surface using a 25 cm
diameter 150 :m mesh net. The technical requirements for Pairovet
tows are: Descent rate of 70 meters per minute, ascent rate of 70
meters per minute. All tows with wire angles exceeding 15/ during
the ascent were repeated.
f. A PRPOOS(Planktonic Rate Processes in Oligotrophic Ocean
Systems) net tow was taken at all stations on line 90.0 and 80.0
as well as stations out to and including station 70.0 on lines 86.7
and 83.3. These stations were occupied as part of the LTER(Long
Term Ecological Research) project. The mesh of the PRPOOS net is
202 :m and the tow is a vertical cast up from 210 meters, depth
permitting.
g.
Up to and including line 76.7, at about 1100 hours on each
day of the cruise a primary productivity CTD cast consisting of six
10-liter hydrographic bottles was carried out. The cast
arrangement were determined by a Secchi disc observation. The
purpose of the cast was to collect water from 6 discrete depths for
daily in situ productivity experiments. Measurements of extracted
chlorophyll and phaeophytin were obtained with a fluorometer.
Primary production was measured as C14 uptake in a 6 hour in situ
incubation. Nutrients were measured with an auto-analyzer. All
radioisotope work areas were given a wipe test before the departure
of the SIO technical staff.
h. During transit between stations, a bird observer and marine
mammal observer recorded locations and species of various sea birds
and marine mammals.
i. During transit between most daylight stations, an acoustic
hydrophone array was towed off the stern with a cable/winch to
record sounds from marine mammals. Upon approaching a station, a
sonobuoy was deployed one nautical mile prior to stopping for
station work.
2.
The egg pump (CUFES - Continuous Underway Fish Egg Sampler)was
mounted inside the ship’s hull drawing water from a depth of three
meters. During the grid occupation, the pump ran continuously
between stations to sample any pelagic fish eggs.
3.
An additional nine stations were occupied within the CalCOFI
pattern for SCCOOS(Southern California Coastal Ocean Observation
System). These were 20 meter depth stations and consisted of a CTD
lowered to within a few meters from the bottom and a Bongo tow.