One week down and two to go. This week we set off on a five-day cruise to collect deep-sea, pelagic zooplankton using a tucker trawl. A group of about 10 graduate students and professors from three different universities came on board and brought along a fully stocked field lab. We spent Monday loading up the gear, setting up the tucker trawl and planning the deployment schedule. I worked with Denis to securely fasten the CTD to the tucker trawl frame, a complicated task as the CTD would be dragged through tons of water for several hours. With the help of several bolts, screws, washers, electrical tape and countless zip ties, Denis and I were finally satisfied that every wire, connector and plug was securely fastened. 
Our first deployment was early the next morning. I groggily climbed out of bed at 4:00 am and made my way to the deck, where scientists and marine techs alike were congregating in preparation for our first deployment. We all worked together to make sure the Tucker Trawl was properly assembled, the CTD and release timer securely fastened, and the net untangled and ready to deploy. Finally, we were ready to toss it into the water. Using the hydraulic crane and several lines, we slowly lifted the frame off the deck, lowered the collection tube into the water and swung the frame off the deck. The last step was to pull the securing line which release a set of cables and opened the net as it sunk into the depths of the ocean. The trawl was going to be dragged along behind the boat for six hours between 500 and 700 meters. As the cruise was accommodating three separate projects, the scientists on board were hoping for an eclectic sample of zooplankton and pelagic, deep-sea organisms. Primarily, the projects involved collecting various species of bioluminescent shrimp so as to dissect and analyze the bioluminescent component of their physiology.
While we waited for the trawl, I was enlisted to assist with the cleaning and waxing of the awnings on the top deck, a tedious but necessary task for the proper maintenance of the boat. The first mate then requested my help to organize the navigation charts, which was the perfect opportunity to learn a bit more about the different kinds of charts and how to read them.
At last, the six hour trawl was complete and the net was dragged back on board and greeted by an enthusiastic swarm of scientists, all eager to see what treasures the extensive trawl had gathered. I can honestly say the crew of scientists was not disappointed as they dragged bucket after bucket of a thick soup of organisms and seaweed into the lab. The next few hours were spent sorting the shrimp, fish, and other invertebrates into neat groups by species, and often, subspecies. They were kind enough to tolerate me as I excitedly buzzed around the lab asking several questions about the nature of bioluminescence, its purpose and the underlying physiology. I even got to observe larval shrimp under a microscope as a professor enthusiastically explained the nature of a double retina in the developing shrimp. Much to my delight, the trawl had also gathered several types of bycatch, many of which were adorable, miniature versions of marine animals. My favorites were the tiny, larval squid and on occasion, the smallest larval crab I have ever seen. Luckily, I was surrounded by a group of biologists that were all eager enough to teach me about the nature of these fascinating deep-sea organisms and their unique biological adaptations.
And so the cruise continued as we tossed the trawl back in the water and waited with baited breath for the next haul of organisms.
After deploying the trawl three times throughout the day and night, we came across our first technical problem. The timed release mechanism that was mounted on the frame of the tucker trawl and provided the crucial function of sealing the collection chamber at the end of the net and protecting sensitive bioluminescent organisms from excessive exposure to sunlight stopped working. It turns out that water got into the previously watertight chamber that housed the batteries and electrical trigger mechanisms and fried the entire system. Luckily, we have highly qualified and capable engineers and marine techs on board that were happy to attempt to fix the problem. We took the trigger mechanism apart, piece-by-piece, and replaced the corroded battery circuit with a new one. I had an opportunity to hone my wire stripping, crimping, and replacing skills as we rebuilt the mechanism.
After waiting a few hours for the silicon holding the circuit in place to set we finally got a chance to test it out. Unfortunately, despite our optimism, it did not work. It looked like the engine in the trigger mechanism itself was damaged so we decided to replace the entire engine, which of course meant undoing all our previous work. But, step-by-step, we took the machine apart and replaced the centrally located engine. After several cut and crimped wires and even threading new holes for the screws (we think there was a manufacturing error where the bolt holes on top of the casing for the engine had no threading) the trigger mechanism was finally fully rebuilt and once again we waited with bated breath to see if our efforts would pay off. Thankfully, it turned out that the engine was once again fully operational, much to our and the scientists delight.
Much like the days before, the rest of the week involved a series of trawl deployments, monitoring, and recovering. However, on Thursday, the scientists on board allowed me to assist with the sorting of the organisms they collected. They gave me a pair of forceps and a tray of deep-water pelagic organisms and patiently taught me to distinguish between several fish, shrimp, and other amphipods. I spent the day working the trawl and picking through marine organisms, sargassum and debris. The experience was fascinating as I got to observe several deep-sea organisms that few people get to witness in person.
Our final day had a very early morning start that resulted in a pleasant surprise. I joined the scientists in the dark room on their last trawl collection and was delighted to sea the Acanthephyra purpurea, a fascinating shrimp that spews a cloud of bright blue bioluminescence to distract predators, and we were even lucky enough to see it spit out a beautiful bioluminescent cloud. I also got to se several luminescent copapods, pyrosomes, and jellyfish. It was an awe-inspiring experience to see so many deep-sea and elusive organisms up close and personal.
The rest of the day was spent honing my amphipod sorting skills and learning about several new animals, including my new favorite, the phronima, a tiny parasitoid that lives inside a hollowed out salp and supposedly inspired “alien” from the movie by the same name. The cruise was an incredibly mix of technical skills and biological research and was a incomparable learning opportunity that I took full advantage of. A cruise I will certainly not forget any time soon.
After several hours navigating along the Florida coast, we finally arrived at our first station where the NOAA team planned to deploy the CTD. I watched as the CTD was slowly lowered with the hydraulic crane into 600 meters of water. Once at the bottom of the water column, the CTD was slowly pulled through the water, stopping at periodic intervals to collect water samples using a trigger mechanism connected to the fiber optic cable found within the cable used to hoist the CTD. As the massive contraption was dragged through the water column it also collected and transmitted real time conductivity, temperature, and depth readings, which the NOAA scientists eagerly monitored on a screen in the dry lab.
Once the CTD was back on the deck, water samples were partitioned into oxygen content readings, organic compound samples, and salinity samples, all of which were carefully collected, processed, and stored away for future analysis. Since there wasn’t much to do in the way of mechanics or engineering, my role was to assist in the collection and processing of the oxygen content samples, which primarily involved carefully filling bottles with aliquots of water samples and adding two compounds that helped quantify oxygen content. 
We started deploying the CTD and the drifters around 6:00 in the afternoon and were not done until about 7:00 the next morning. It was a long and exhausting night, but one full of learning opportunities and unforgettable experiences.
If the smaller boat caught one, the team on the Walton Smith would attach a tennis ball to a fishing pole and cast this ball to the smaller fishing boat. The team on the smaller fishing boat would then attach this line to the line they had caught a fish with, so that the Walton Smith team could then reel the fish in to them.
