Hatchet fish, pyrosomes, krill and copepods…
Fangtooth from the Oozeki, picture by Joel Van Noord.
Busy day out here, lots of wonderful stuff coming up in the Bongos,
Oozeki and the MOCNESS. The MOCNESS caught some amazing little hatchet
fish along with the plankton, which was thick and soupy like yesterday.
The Oozeki caught some really interesting midwater fish including a perfect little “fangtooth”. Nightime sampling is always fun, as the birds are flying onboard and I think the light kind of blinds them because they all land like a bunch of gooney birds! I have been able to get some of the extra samples of the trawls and preserve them to bring back to show my class. Hatchet fish, pyrosomes (glow in the dark tunicates!) and several types of krill and copepods.
Mesopelagic diversity , picture by Joel Van Noord
To answer one of the questions from a teacher: “ What is the temperature
difference across the front?”
The temperature difference is small, only
about 1 degree C and salinity is only about a couple of fractions of a
thousand. (although for salinity that can be significant), but the
temperature and salinity are only indicators of the different water masses,
it’s the nutrients that are the key to the biomass and the different water
masses are indicators of where the nutrients are.
We are recovering the sediment traps tomorrow and I will send a picture of the inside of the Isotope Van and a little explanation of how they are using the sediment traps to measure Silica in the water (and why we would care how much silica is in the water….hint: because some species of phytoplankton use this material to make their support structures….kind of like little glass houses).