Woods Hole Oceanographic Institution

Cruise Planning Synopsis

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R/V Oceanus

Cruise Party

Dennis McGillicuddy: Chief Scientist, Principal Investigator
Woods Hole Oceanographic Institution Bigelow 209A, MS#11 Woods Hole, Ma. USA 02543
+1 508 289 2683

Departure: Oct 1, 2010

Woods Hole

Arrival: Oct 21, 2010

Bridgetown, Barbados

Operations Area

Depth Range: min / max (m)
Will the vessel be operating within 200 NM of a foreign country? yes
Are visas or special travel documents required? no

Science Objectives

The diazotroph Trichodesmium spp. constitutes a major pathway of nitrogen flow into marine planktonic ecosystems, but estimates of its impact on global nitrogen budgets vary widely. Sampling is made difficult by the fragility of the organism with the consequence that Trichodesmium spp. are difficult to manipulate in both field and laboratory experiments. Optical methods that sample the organism nondestructively are thus appealing. A recent transatlantic survey using the Video Plankton Recorder (VPR) revealed unexpectedly high abundance of Trichodesmium spp. at depth, suggesting the vertical distribution of the organism within the euphotic zone may be more uniform than previously thought (Davis, C.S. and McGillicuddy, D.J., 2006. Transatlantic Abundance of the N2-Fixing Colonial Cyanobacterium Trichodesmium. Science, 312: 1517-1520). Application of a simple bio-optical model of productivity to the observed profile of abundance suggests the depth-integrated nitrogen fixation rate could be three to five times higher than that based on the canonical profile of exponential decrease in abundance with depth. However, the observations described in Davis and McGillicuddy (2006) come from a latitude range where Trichodesmium spp. are not especially abundant. This raises a key question: is there a similar vertical distribution in waters further to the south, where Trichodesmium spp. are an order of magnitude more abundant overall? If so, are the deep populations actively fixing nitrogen? If so, the implications for the global nitrogen budget would be substantial.

To answer these questions, we will undertake two cruises to survey the waters of the southern Sargasso Sea and tropical Atlantic, where Trichodesmium spp. are commonly found in high abundance. Along-track VPR measurements will document the abundance and distribution of the organism on the scale of meters to thousands of kilometers. Standard hydrographic station work will provide for comparison of VPR-based estimates with microscope counts, as well as some additional in situ optical methods. A combination of nifH gene expression assays and direct determinations of N2-fixation rates will be made to assess whether or not the deep populations are actively fixing nitrogen. These observations will be synthesized in the context of an eddy-resolving numerical model. This will permit investigation of the mechanisms controlling the vertical and horizontal distribution and abundance of Trichodesmium spp. at multiple scales, including the enigmatic association of relative maxima in abundance with anticyclonic eddies (also described in Davis and McGillicuddy, 2006). Moreover, integration of these observations into the numerical model will facilitate revised estimates of nitrogen fixation by Trichodesmium spp. in the North Atlantic.

Science Activities

Departing from Woods Hole, we will set a course for BATS 31 40N, 64 10W.  VPR will be deployed upon crossing the shelf break.  XBTs will be deployed hourly.  VPR will be recovered each day at 0930 so CTD station work can begin promptly at 1000.  Upon completion of CTD/pump station work, VPR will be redeployed and underway sampling will recommence.

After sampling at BATS, we will proceed southward along 64W to 20N, then turning southeastward to 10N, 45W.  Alongtrack sampling is flexible, and we will adjust our course according to satellite altimetry and SST / ocean color imagery.

Additional Info

Pre-cruise Planning Meeting: Visit WHOI
Meeting Notes: JULY 14 @ 1400 hrs at 38 Water St. 2nd floor conference room.


Supporting documentation:

Notes: LN2 van added onto cruise to support science supply.  Barbados does not have commercially available LN2 any longer.


Funding Agency: NSF
Grant or contract number: OCE-0925284

Scientific Instrumentation for R/V Oceanus

Other Science Vans:

Shipboard Equipment

Bathymetry System 12 kHz
Sippican XBT System (Mark 21)
Bathymetry System 3.5 kHz
ADCP 75 kHz
ADCP 150 kHz
Science Underway Seawater System
Deionized Water System
Fume Hood

CTD/Water Sampling

Seapoint STM turbidity sensor
911+ Rosette 24-position, 10-liter bottle Rosette with dual T/C sensors
SBE43 oxygen sensor
Wet Labs ECO-AFL fluorometer
Wet Labs C*Star transmissometer (660nm wavelength)
Biospherical underwater PAR (1000m depth limit) with reference Surface PAR

Critical CTD Sensors

CTD-Related Equipment

ECO/AFL and STM sensor (WHOI owned)

Hydrographic Analysis Equipment

Salt Bottles (2 cases of 125 ml provided)

MET Sensors

Barometric Pressure
Wind speed and direction
Air temperature
Relative Humidity
Short Wave Solar Radiation

Sample Storage

Refrigerator 8.6 cu. ft.
Chest Freezer (Household type) 0°F
Freezer -70°C 3.2 cu. ft. ea.
Storage Notes: Need 2 chest freezers (-20C) in main lab.


Will you be using Long Base Line (LBL) navigation? no
How many nets? 0
How many tansponders? 0
Will you be using Doppler/GPS navigation? yes


CTD Winch with .322" Electro-mechanical wire
Winch Notes: VPR winch and block
Wires Notes: VPR cable: 3 fiber optic, 3 copper 0.322" opto-electric

Standard Oceanographic Cables

Slip ring required? yes Number of conductors: 3
Non-standard wire required? yes Type: VPR cable
Traction winch required? no Describe: 
Science Van 1
Type/size: Liquid Nitrogen Generator Van Location: Main Dk Stbd Side
Water: yes Power:yes
Science Van 2
Type/size: General purpose lab van Location: 01 deck
Water: yes Power:20A

Specialized Deck Equipment

Mooring Deployment/Recovery Equipment Required: no Type: 
Cruise Specific Science Winch Required: no Type: 
Nets Required: no Type: 

Over the Side Equipment

Will you be bringing any equipment (winches, blocks, etc.) that lowers instruments over the side? yes Details:
VPR winch and block

Special Requirements

Elecrical Power: yes Identify: Power for VPR
Equipment Handling: no Identify: 
Inter/intraship Communications: no Identify: 
Science Stowage: no Identify: 
Water: no Identify: 

Additional Cruise Items/Activities

Explosive Devices:no Portable Air Compressors:no Flammable Gases:yes Small Boat Operations:no SCUBA Diving Operations:no

Hazardous Material

Will hazardous material be utilized?yesDescribe deployment method and quantity:

Radioactive Material


Additional Information

Is night time work anticipated on this cruise?yesSpecialized tech support (Seabeam, coring, other):
VPR techOther required equipment and special needs:
pumping system to be attached to CTD

2 incubators with fold-down legs to be set up on aft deck

6 wire baskets: 3 on 01 deck for carboy storage, 3 on main deck for pump hose.

LN2 delivery in Barbados to recharge dewars for transit back to WHOI.

Checklist & Notes


U.S. Customs Form: yes
Diplomatic Clearance: no
Date Submitted:
Date Approved:
Agent Information:

Attn: Scientist's Name OC469-1
c/o WHOI
266 Woods Hole Rd.
Woods Hole, MA 02543

Contact: Eric Benway
Phone: (508) 289-3770
Fax: (508) 457-2185
Email: ebenway@whoi.edu

Attn: Scientist's Name OC469-1
c/o DaCosta Mannings Inc.
St. Michael

Contact:  Glyne St. Hill, Manager
Email: gsthill@dmishipping.com
Phone:(246) 430-4804
Fax: (246) 431-0051

Contact:  David Priddee, Operations Manager
Email Address: dpriddee@dmishipping.com
Tel. no. (246) 430-4819
Cell no. (246) 231-5348

Contact:  Arlin Kellman, Assistant Operations Manager
Email Address: akellman@dmishipping.com
Tel. No. (246) 430-4825
Cell no. (246) 230-4353

Primary Contact:  Anthony Oliver, Operations Coordinator*
Email Address: logistics@dmishipping.com
Tel. no. (246) 430-4881
Cell no. (246) 231-5382
Fax: (246) 431-0878

*Note: All requests and correspondence should be sent to Anthony Oliver at the email address above with copies to David Priddee and Arlin Kellman.

Agent and WHOI contacts should be copied on all communications. It is requested that shipment information of any equipment be communicated to the Agent and to all WHOI contacts

US Customs forms #4455 will need to be filled out with science equipment, such as laptop computers, microscopes, lab equipment with serial numbers.  Anything of significant value and having a serial number will need to be listed. 
Lab supplies, consumables do not need to be listed. 
Isotope Use Approval: no
Isotope Notes:
SCUBA Diving: no


SSSG Tech:
Loading at WHOI SEPT 29 and 30th.