Wednesday, June 18, 2014

Last Field Day (Dana Nieuwkerk)

Yesterday we spend 13 hours at-sea aboard the R/V Weatherbird II!
Docked after a long day!
The boat trekked 18.25 miles SW of Tampa Bay, in the mid-shelf of the Gulf of Mexico, known to our crew as ‘Site 1’. I was part of the CTD team at Site 1, which appeared much larger than the CTDs we have been using at other universities.
CTD and niskin bottles for water quality and water sampling.
However, the CTD is actually attached at the bottom of the equipment – the majority of the machine is composed of niskin bottles, which are fired shut at predetermined depths to collect water samples. We collected samples from the bottom, middle, and surface. Fortunately, Drew (a crew member) advised us to fire two bottles at each depth in case one failed to shut, which did happen. From the data, we were able to see temperature dropped 2C at the bottom (as compared to the surface) but Chlorophyll a was significantly higher at depth than at the surface, which was attributed to light stress at the surface.
Me, Kristiana, and Heather! Ready for dredging!
My team also did a 10 minute dredge at Site 1, which resulted in several sponges, shells, macroalgae, and crabs. Shells proved to be the most difficult to identify for our group, likely because we, collectively, have the least experience with mollusks. I was most excited to see a jubilee octopus crawling above the heap of unsorted material that we were pulling out of the dredge!
A few results of our dredge at Site 1.
After finishing identification and heading inshore, we stopped ‘outside of the Skyway’ at ‘Site 2’. My team was responsible for the neuston pull and the bongo net pulls. Both pulls are meant to collect plankton, neuston collects plankton at the surface while the bongo nets collect plankton of the mid-water column, which was 2-3m at Site 2. Both pulls produced several Dana’s Blue Crab; however the bongo pull also produced a lined seahorse! We analyzed zooplankton of both pulls in the lab today and found there was a much larger abundance and diversity of zooplankton in the bongo samples as compared to neuston samples, indicating zooplankton habituate the mid-water column moreso than the surface.
Kristiana and I hooking up the flow meter to our bongo nets. 
Lined seahorse from our bongo pull! 
Pregnant Dana's blue crab in our neuston pull. 
Neuston pull "action shot"

Overall, my first experience on a research vessel was incredible! Using all of the equipment is an unparalleled experience that I hope to repeat in the future!

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