- NOAA Ship: NOAA Ship McArthur II
- Cruise Number: 0907M2
- Cruise Dates: July 14 – August 5, 2009
- Cruise Title: CalCOFI Survey.
- Study Area: US/Mexican border to Monterey, CA out to 400 nautical miles.
- Transit from Seattle to San Diego: July 6 – 11, 2009
- Ship loading and gear preparation: July 11 – 13, 2009.
- Leg 1: July 14 – August 5
- Station 93.3/26.7 - 66.7/90.0
- Arrive San Francisco, CA: August 5, 2009
- The ship will offload scientific gear in San Francisco, CA.
Sponsoring Institution: NOAA/NMFS, Southwest Fisheries Science Center (SWFSC)
Fisheries Resources Division (FRD)
Cruise Description and Objectives:
- To conduct continuous underway sampling of surface waters. Temperature and salinity will be automatically logged by computer with the output from the GPS navigational unit.
- To continue an ongoing assessment of pelagic fish stocks between La Jolla and Monterey Bay, California.
- To monitor environmental conditions within the CalCOFI survey area.
- To make continuous observations of sea birds and marine mammals.
- To record continuous acoustic targets obtained with the EK-60 scientific sounder.
PLAN OF OPERATIONS
- The McArthur II will conduct operations in the Southern California Bight as well as occupying line 76.7 and just north of Point Conception and line 66.7 out of Monterey Bay.
Each standard CalCOFI station will include the following:
- CTD/Rosette - consisting of 24 10-liter hydrographic bottles will be lowered to 500 meters (depth permitting) to measure physical parameters and collect water at discrete depths for analysis of: salinity, nutrients and chlorophyll. CTD casts on line 66.7 will be down to 1000 meters.
- CalBOBL (CalCOFI Bongo) - standard oblique plankton tow with 300 meters of wire out, depth permitting, using paired 505 um mesh nets with 71 cm diameter openings. The technical requirements for this tow are: Descent wire rate of 50 meters per minute and an ascent wire rate of 20 meters per minute. All tows with ascending wire angles lower than 38deg or higher than 51deg in the final 100 meters of wire will be repeated. Additionally, a 45deg wire angle should be closely maintained during the ascent and descent of the net frame.
- Manta net (neuston) tow - using a 505 um mesh net on a frame with a mouth area of 0.1333 m². Tows are 15 minutes in duration at a towing speed of approximately 1.5 - 2.0 knots. Wire angles should be kept between 15deg and 25deg.
- Weather observations.
- Pairovet net - will be fished from 70 meters to the surface (depth permitting) using paired 25 cm diameter 150 um mesh nets out to and including station 70. The technical requirements for Pairovet tows are: Descent rate of 70 meters per minute, a terminal depth time of 10 seconds and an ascent rate of 70 meters per minute. All tows with wire angles exceeding 15deg during the ascent will be repeated.
- PRPOOS (Planktonic Rate Processes in Oligotrophic Ocean Systems net - will be 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 are occupied as part of the LTER (Long Term Ecological Research) project. The mesh of the PRPOOS net is 202 um and the tow is a vertical cast up from 210 meters.
- Primary productivity - at about 1100 hours on each day of the cruise a primary productivity CTD cast consisting of six 10-liter hydrographic bottles will be carried out. The cast arrangement will be determined by a Secchi disc observation. The purpose of the cast is to collect water from six discrete depths for daily in situ productivity experiments. Measurements of extracted chlorophyll and phaeophytin will be obtained with a fluorometer. Primary production will be measured as C14 uptake in a six hour in situ incubation. Nutrients will be measured with an auto-analyzer. All radioisotope work areas will be given a wipe test before the departure of the SIO technical staff.
- A light meter - will be used to measure the light intensity in the euphotic zone once a day with the primary productivity cast.
- Thermosalinometer Sampling - The ship will provide and maintain a thermosalinometer (TSG), which is calibrated and in working order, for continuous measurement of surface water temperature and salinity. A backup unit (calibrated and in working order) will also be provided by the vessel and remain aboard during the cruise. The Scientific Computing System (SCS) will serve as the main data collection system.. All SCS data will be provided to SWFSC personnel at the completion of the cruise.
- Acoustics –The scientific EK-60 depth sounder will be operated, at 38, 70, 120 and 200 KHz and interfaced to a data acquisition system to estimate micronekton biomass between 0 and 500 m. The vessel's EQ-50 depth sounder (or comparable) may be used at the discretion of the Commanding Officer, but will normally remain off while underway. The ship shall inform the Cruise Leader of any use of the vessel's EQ-50, as it interferes with the signals received on the scientific EK-60. Its use will be continuous. On the day of departure the ship will move to a predetermined location within the bay to perform calibration of the EK-60. Most likely this will be an anchorage in the channel in front of Harbor Island, San Diego.
- Marine mammal and sea bird observations - During transit between stations, a bird observer and marine mammal observer will be recording location and species of various birds and marine mammals.
- Acoustic hydrophone - During transit between most daylight stations, an acoustic hydrophone array will be towed from the stern with a deck loaded winch to record sounds from marine mammals. Upon approaching a station, a sonobuoy will be deployed one nautical mile prior to stopping for station work.
- SCCOOS - An additional nine stations will be occupied within the CalCOFI pattern for SCCOOS (S. California Coastal Ocean Observation System). These are 20 meter depth stations and will consist of a CTD lowered to within a few meters from the bottom and a Bongo tow. These stations are included in the original station plans provided to the ship.