DRAFT CRUISE PLAN R/V WECOMA

W9706B

Oregon State University, College of Oceanic and Atmospheric Sciences

FILING DATE:

April 11, 1997

TITLE:

Southeast Bering Sea Carrying Capacity

CONTRACT/GRANT NUMBER:

04NA67RJ0151

PRINCIPAL INVESTIGATORS:

Phyllis J. Stabeno, NOAA/Pacific Marine Environmental Laboratory, 206-526-6453
Terry Whitledge, Univ. of Texas, Austin, 512-749-6777
Susan Henrichs, Univ. of Alaska, Fairbanks, 907-474-7807

CRUISE DATES:

June 10-27, 1997 W9706B

PURPOSE:

This cruise will investigate bio-physical processes in the southeast Bering Sea, an area which supports an abundance of species economically important species. This cruise will address two main objectives: Objective 1: will take measurements (CTD, nutrients, zooplankton and phytoplankton) to investigate the origin and dynamics of nutrients on the southeast Bering Sea shelf and its relationship to physical and biological processes; phytoplankton growth studies; and sediments. Objective 2: Optical measurements will be used to explore the influence of mesoscale eddies on the interaction of lower and higher trophic levels.

ITINERARY:

The ship will depart Dutch Harbor and steam to the site of optical studies. The position of these studies will center on an eddy, determined from earlier cruises or satellite altimeter images. Duration of this portion of the cruise will be 5 days. We then transit to mooring 6 (Figure 1). Following the track line a series of CTD/nutrients/net tows will be done. Measurement of phytoplankton growth rates and sediment sampling will be done on the shelf at mooring sites 2, 3 and 4. We will return to mooring sites 2 and 3 to measure phytoplankton growth rates a second time. After completion of objective 2, we will return to eddy site and do transect collecting optical and CTD data.

A detailed itinerary for Objective 1 can found in Table 1. Cruise track for objective 1 is shown (Figure 1), while the cruise track for objective 2 will be determined prior to sailing. The position provided in the detailed itinerary is only an approximation and will be modified.

RADIOACTIVE METHODS:

None

HAZARDOUS MATERIALS:

formalin (1 liter)
acetone (1 gallon Hendricks, 1 gallon optics, )
0.01 N HCL (1 gallon)
Sodium nitrate 1 mM (0.2 liter)
Ammonium chloride 1 mM (0.2 liter)
Sodium carbonate 0,25 M (0.2 liter)
Sodium bicarbonate 0.25 M (0.2 liter)
Cadmium*
Tin (II) chloride*
Sodium hydroxide*
L-abscorbic acid*
hydrochloric acid HCl (.25 gallon optics)
ammonium chloride*
N-1-naphthylethylenediamine dihydrochloride*
Dimethyl Sulfoxide (DMSO) (1 gallon optics, )
3-(3,4-Dichlorophenyl)-1,1-Dimethylurea (DCMU) (1.5 gallons optics)
Liquid Nitrogen (1.5 gallons optics,)
Phenol*
Sulfuric Acid*
Potassium Phosphate Monobasic*
D-Tartaric Acid*
Potassium Nitrite*
Sulfanilamide**
Amalgamated Cadmium Filings, Suspension, Apha for Nitrate Cadmium, Granulated
Sodium Nitroprusside*
Ammonium Molybdate, 4-hydrate*
Sodium Fluosilicate*
Sodium Lauryl Sulfate*
Stannous Chloride, Dihydrate*
Antimony Potassium Tartrate, Trihydrate*
Sodium Citrate Dihydrate*
Cupric Sulfate*
Imidazol*

*amounts to be provided

MSDS provided prior to sailing

SAMPLING PLANS:

(1) Collection of zooplankton and phytoplankton samples. Collection will
be made with standard bongo net tows (150 and 333 micrometer mesh). Some
tows with a Tucker trawl (1 mm mesh) (aka NIO net) will also be made to collect euphausiids. Samples will be rough sorted on board and stored frozen . First priority for sample collection are the "X" stations centered on each mooring site, M2, M3, M4. Second priority is 1/2 to 1/3 of the CTD stations on lines connecting the mooring sites.

(2) Measurement of phytoplankton growth rates using a N-15, C-13 double isotopic label technique: Samples will be collected twice per day from 6 light-depths and incubated with added tracer in deckboard incubators. Samples must be collected so that there is enough daylight for a 6 to 8 hour incubation, i.e., sampling times of around 0600 and 1300-1400 are optimal. First priority are the mooring sites M2 and M3 and selected stations from the CTD line connecting them. Reoccupation (twice) of the mooring stations to get a time-series of productivity is also a priority. M4 and the CTD line to it may also be sampled as time is available. Chlorophyll will be measured by fluorometry at CTD stations. Alkalinity will be measured at productivity stations. PAR measurements will also be made vs. depth at productivity stations.

(3) Sediment sampling: A small box corer will be used to collect samples of surface sediment, which will be frozen for later analysis. Samples will be collected at the "X" stations at and around the mooring sites M2, M3, M4. Ideally 3 replicate cores would be collected at each station.

(4) Optical Component (Ocean Color Monitoring)
The profiling radiometer is a free-falling device while the reference radiometer floats at the surface. Weather permitting, the profiling and reference radiometer should be deployed simultaneously. Both are typically deployed off the stern of the ship by hand and then given a chance to drift away from the ship. If possible, the wind should be such that the instruments drift astern. If ship drift due to wind or currents is insufficient then a little headway via the engines is required. Communications is maintained between fantail and bridge at all times. Both instruments are attached to the ship via independent Kevlar cables that serve as both tether and power/data communications. A typical station consists of 3-5 casts with the profiling radiometer, requiring approximately 15 minutes total, depending on the depth of the water column. After the profiles are completed the reference radiometer is allowed to float for an additional 15 minutes while the profiling radiometer is recovered and a surface bucket sample is collected. Total time for any one station is usually 40 minutes, also dependent upon water column depth. If conditions are correct, the radiometers can be deployed at the same time as the CTD. The radiometers will only be deployed when the sun is more than 15 degrees above the horizon, and should be deployed during every CTD cast within that time frame. In particular, a solar noon profile should be collected daily.

Drifters: Six satellite-tracked drifters will be deployed during the cruise. Exact location of ocean color monitoring (OCM) drifter deployment will be decided during the cruise based on locations of eddies determined through either satellite imagery or real-time observations. These will be deployed by hand by two people. Prior to deploying of the drifters, a CTD cast with Niskin bottles and a radiometer deployment should be performed. The ocean color monitoring (OCM) drifter is then deployed over the side and allowed to float free. They will not be recovered.

CTD Casts: CTD casts are necessary to determine both the physical and biological characteristics of the water. Since eddies can influence the density of the water column to several hundred meters, most CTD casts will extend to the bottom or 1500 meters. The CTD should be equipped with an in situ fluorometer and a beam transmissometer. Proper zero and air calibrations of the beam transmissometer must be collected prior to each cast. On the upcast we will collect water at 8-12 depths using Niskin bottles on the CTD rosette. The exact number and locations of CTD casts is dependent upon the size and location of the eddy. After the release of an OCM drifter in the presumed center of an eddy, we will begin a transect toward the edge, performing CTD casts at regular intervals. Upon clearing the eddy, the ship will reverse course and begin a transect back into the center, again performing CTD casts at regular intervals. During dark, CTD casts and ADCP transects will be done across the eddy, to obtain measurements to determine the its dynamics.

EQUIPMENT REQUIRED:

USER SUPPLIED EQUIPMENT:

Optics group:

6 optical drifters (each box 3x3x3 ft and weighing ~70lb) *
1 satellite-tracked drifter (box 3x3x3 ft and weighing ~50lb)*
Typically 10-12 cases, each about 3x2x2 feet and weighing 50 lbs.*
1 profiling radiometer,
1 reference radiometer,
4 laptop computers
2 lab fluorometers
misc. lab equipment
pH meter
20 cm and 60 cm bongo net (150 and 333 micrometer mesh), frames, 75 lb weight*
Tucker trawl (1 mm mesh) (aka NIO net) bridles, frame, messengers, weights etc.*
PAR instrument;*
pH meter*
small box corer*
kiddie wading pools for phytoplankton growth exp.*
computers (Sun work station, with monitor, disk drive, printer)*.
2 boxes of computer paper*
nutrient sample bottles*
chemicals
tapes for VCR

The nutrient group will bring an analytical chemical laboratory in 20-25, 70 lb boxes weighting a total of ~2000lb and occupying 60 ft3 of space. Reasonably accessible storage space must be made available to the empty boxes so the scientists can repack their gear at cruise end to depart the ship efficiently. All this equipment must be loaded prior to the cruise and unloaded directly after the cruise in Dutch Harbor.

*This equipment will be loaded in Seattle.

OTHER BULKY HEAVY ITEMS:

none?

Communications:

We will need INMARSAT phone access.