Deployment: WB1105

Note:  Deployment Description was obtained from a pre-cruise cruise plan.

The goal of this cruise is to investigate the impact of the BP oil spill on the northern Gulf of Mexico ecosystem, focusing on the mesopelagic fauna. Results will be compared to observations and measurements obtained during the August  R/V Weatherbird cruise in the same region and the many other cruises preceding.
Specific objectives include:

-  Determine hydrocarbon concentrations in water column samples obtained via the CTD.  Characterize the chemical composition of oil (chemical fingerprint) and note what depths water column backscatter was observed.
   
-  Assess mesopelagic communities at two reference stations and one within the plume with respect to:
    - abundance and distribution
    - species composition

-  Obtain frozen specimens of 10 target species for laboratory determinations of evidence of exposure to oil

Geographic Area: The cruise will originate and terminate at USF/CMS in St. Petersburg, FL.  We will collect samples at three general locations: USF standard station (27o N 86o W) ; Midway station: (27o 55’N 86o 55’W), and vic DSH 9 (28o 38.19’ N 87o 52.11’ W).  To the extent that time permits we will
re-occupy the Aug 2010 Weatherbird deepwater stations (DHS10, DHS09, DHS08), where subsurface oil was detected.
 

The WB II will depart from Bayboro and dead head to standard station  - roughly a 180 NM transit – at 10 kts about 18 h.  Sampling at each of the general sampling sites will consist of two types of midwater tows interspersed with CTD casts.  Tows will be at the most comfortable heading and will remain within 20 NM of each general station location. 

Day tows will used the MOC-4 exclusively and will be in the upper 1000m of the water column.  The winch will be in constant use during all tows, either paying out or taking up. Night tows will initially use the MOC-4, then the net will be switched to the 9 m2  Tucker tow for repetitive tows in the upper 400 m for the purpose of maximizing catch of target species.

Station occupation will partially be determined on site but tentatively will be 2 d, 1d, and 2 d, at each of the general locations described above.  DSH 10 and 8 are put in for reference.