Reading about zooplankton in a book is one thing; having a net full of the myriad little ocean drifters glow in the dark when you poke them with a wet finger is quite another.
Eleven undergrads, four graduate students and Duke Marine Lab director Cindy Van Dover recently set sail aboard the brigantine research vessel Corwith Cramer to sample the tiny sea life west of the Florida Keys. It was the hands-on portion of a four-week course on invertebrate zoology.
They hoped to net zooplankton in at least six locations on either end of a broad channel between the Dry Tortugas and the Marquesas. It's an area of water that pulses back and forth with the tide, connecting a shelf area in the Gulf of Mexico with the Gulf Stream. Would the zooplankton be the same or different on each side? What would that mean?
Surprisingly little science has been done about zooplankton around the Florida Keys, explained Karen Neely, a PhD student in ecology who mentored the students on board the Cramer. Yet the abundant, tiny creatures are widely considered the glue that holds the entire ocean food chain together and they help balance water chemistry.
Though none of the undergrads had any special background in sea research or zooplankton, a one-week crash course at the Marine Lab with William Kirby-Smith had them prepped enough to be able to look things up in the ship's small reference library.
Unfortunately, the area also hosts its share of storms. For three solid days, they were unable to collect data as the Corwith Cramer pitched about in heavy seas. They hung on for dear life, when they weren't throwing up over the rails.
"Most of the time things don't work out in oceanographic research, so you always have backup plans," said Josh Osterberg, a fifth-year graduate student in marine biology, who served as chief science officer for the cruise. "We definitely need another cruise!"
Ship's Log: I’ve never really sailed on the ocean & it just makes you realize how much is out there to study. I may not be really passionate (yet!) about invertebrates, but their role in the grand scheme of things is just as important as everything else. That interconnection between everything is a pretty fascinating concept. Even the connections between different fields of study is really important.
On this boat there are scientists (from a lot of fields), engineers, deckhands, cooks, medics, & so much more I’m sure. Every single one of them is integral to the success of this trip. Everyone knows this & the fluidity of their actions is proof of this fact. There is reliance in all parts of life on board.
- Friday, 1/18, Sarah Diehl, Duke 2010, Mt. Laurel NJ.
The ship's ecology is a metaphor for the ocean, Neely agrees. "The thing I always want to impress on people is how diverse life on earth is. It's not just about humans. Look at how many kinds of life there are!"
In addition to filtering zooplankton out of various depths of the water, the students took measures of salinity, conductivity and nutrient levels.
Ship's Log: So night watch yesterday was a really interesting experience. I was assigned to the science station and we had a lot of work to do, and we were in a hurry because a storm was supposed to hit us by midnight.
The first thing we did was deploy these two nets that were dragged through the water at different depths to collect all the critters in the water. We’d already done that once before during the day, so I thought it would be much the same old-same old, but boy was I wrong. Once we pulled up the nets and started to rinse them off, we found tons of bio-luminescent critters all over the nets and in the collection jar. They were really cool because they only glowed if they were agitated, and so we’d see little glowing green dots wherever we sprayed the net.
– Sunday, 1/20, Jing Zhong, Duke 2009, Cary, NC.
Had the sampling effort been more complete, thousands of zooplankton specimens would have been brought back in little jars to the Duke Marine Lab in Beaufort, NC for genetic analysis. As it was, "we stopped fixing (preserving) after we realized there we weren't going to get enough," Osterberg said.
Ship's Log: I thought that it was really quite beautiful to see the rough seas, with the waves crashing in the distance. It was really exciting to be on deck because you could see and feel our little ship being tossed around by the elements! We were constantly rocking to-and-fro, so much so that there were times when the deck must have been tilted in a 45 degree angle, and as you’re standing on the quarter deck (the very back of the ship), you could look down and see that the ship was tilted so much that the bow was pointed straight into the ocean!!! And yet we were still perfectly safe, and only occasionally would waves splash up on deck (though it would happen, and I got completely drenched by such a wave).
While I thought this weather was wonderful and a source of great fun, others on the ship were getting very sea sick.
– Sunday 1/20, Jing Zhong.
"Even what little science we got done got across what doing science at sea is like," Neely said. "It's not easy; sometimes you're puking overboard."
Ship's Log: It’s going to be impossible to explain this to anyone back home. How do you put in words the feeling you get when you’re at the helm of a ship at night during a storm and the only thing you can hear is the wind, loud against your ears and all you can feel is the cold rain splattering your nearly numb fingers that clutch on to the wheel, hoping that you won’t be the one who sails completely off course. How do you put into words what it’s like to be washing a net on deck, then feel a stinging sensation on your leg and look down to find that there’s a jellyfish tentacle there. How does one explain a gimbaled table or what it’s like to watch a dolphin swim in the wake of the bow. I don’t know because to sum it up in one word, this trip was indescribable.
- Wednesday 1/23, Esi Waters, Duke 2009, Washington DC. Listen to Esi wax poetic over scyphozoa in her poem about sea jellies.