Written by Chief Scientist, Joe Warren of Stony Brook University.
Well, the cruise is wrapping up as we've now redeployed our last bottom lander and are trying to get a few more environmental samples before we have to start heading North back to Woods Hole.
It's good to get back into the swing of things as the last few nights we've had really poor weather (strong winds and rough seas) which have prevented us from being able to do much sampling. It was too rough to put gear into the water and the seas were rough enough that we had a lot of bubble-noise on our acoustic echosounders on the ship so we couldn't even run our acoustic surveys.
Planning for a month on the ship can be very challenging especially when the weather can be unpredictable. I've done a lot of fieldwork in a variety of places which often have terrible weather so when I designed our cruise plan for this trip, I put in 5 "weather days" so that we would be sure we could get everything we needed to get done out here accomplished. For the first 3 weeks of the trip, we had only needed one of those weather days (the very first day of our cruise when we were stuck at the dock). But in the past week, we've used up 3 more of them.
But all our sampling should be wrapped up in the next 36 hours or so and then we'll hope we can get back to Woods Hole on schedule. I've tried to convince the bridge to just swing by Long Island and drop me off at my house, but so far they have been unwilling to accommodate this request.
Here are some of the other mesopelagic creatures we've caught in our recent tows.
One of the smallest creatures we will catch in our net is a copepod. These crustaceans are amazing animals: they serve as a key link in many ecosystems consuming plants (phytoplankton) and being eaten by larger zooplankton and small fish. They also migrate 100s of meters each day moving between the surface waters at night and deeper, darker water during the day.
This is a larval fish that lots of people reading this blog have probably eaten at some point (when the fish has grown up). It's a mahi mahi. We caught a lot of tropical fish on this trip as our shallower net tows were often in the Gulf Stream which carries warm water from the Caribbean up along the coast of the United States. Some of these tropical larvae can even make their way up to Long Island, New York via rings of warm water that spin off the Gulf Stream and keep traveling north.
The larvae eventually turns into a juvenile fish which more closely resembles the adult, mahi mahi. Some of the crew were fishing during one of our transits in between stations and caught an adult which the galley cooked up for dinner that night. Fresh seafood at its finest! For the record, all the fish caught in our net tows are preserved for analysis and are not put on the menu.
And a final mention to students who are in my MAR 352 course (Intro to Physical Oceanography) who have their final exam tomorrow. If any of them are reading this blog, you should re-read the beginning of Ch 1 of Moby Duck (one of the assigned readings from the beginning of the semester), it'll be helpful information for one of the exam bonus questions. Good luck with the exam!
