Good evening from the RV Atlantis! We are at station 5a
today, but we didn’t do any CTD Casts today because we got into the station pretty
late. Instead we had a science meeting and worked on our projects! Andrew spent
a lot of the day in his rad van processing his samples and finishing
incubations. I just finished my second nutrient addition experiment today, which
basically involved a ton of filtering! This batch was mostly coastal diatoms
and was a plume station- the salinity was about 17! The first batch was a blue
water/edge station with mostly trichodesmium. It will be interesting to see if
the nutrient additions (I am using a control, ammonium, nitrate, and phosphate)
have any effect on chlorophyll A concentration or on phytoplankton community
composition!
As of today we are
officially in Brazilian Coastal Waters, and we have been going in and out of
the amazon river plume with the salinity fluctuating between 36 ("blue
water" or water outside of the bloom), and down to 17 for some of the
plume stations. Yesterday at station 4, we had a very "green" station
with low salinity and an abundance of coastal diatoms such as Calcinodiscus, pseudo Nitzchia, Skeletonema,
Chaetocerous, Guinardia, Melosira, Rhizosolenia, and of course Tricho! These are just the genus names- Andrew
could tell you the many different species!
We've also been getting to look at some amazing deep sea
creature thanks to Debbie Steinberg's zoology group. We've seen a lot larval
crabs, fish, and other marine organisms. We saw some beautiful bright red deep
ocean shrimp (since red light does not reach the deep ocean, they appear black
to predators). We also got to see various black fish with spots called
photophores on their bodies which can change colors. This evening we got to see
a pretty amazing tow that Kristine will tell you about!
It is very hot and humid during the day, but cools down a
bit at night. As the ship moves at night we can see the bioluminescent
organisms glowing in the water. Pretty awesome! More soon! And I promise pictures, but I can't seem to find my camera. Fortunately there are only so many places it can be...
-Rachel
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