Bioluminescence Cruise - Blog 4
Day 2 – Doing Science!
We end Day 1 setting sail into the night, traveling to our first of several sites where we plan to collect
samples. We wave farewell to the Miami skyline, and after a few hours of card games and chess, we
retire to our bunks hoping to get a few hours of sleep before we begin our first trawl. There’s a very
noticeable transition between the calm tranquil waters of the bay and the tumultuous peaks and
troughs of the open ocean. The night is long and our cabins are filled with claps of thunder as we press
on through a typical Caribbean summer storm.
It wasn’t the most comfortable of nights, but eventually I find myself dozing off, waking only with sunlight that shines through the porthole window in my bunk.
The arrival of the sun means it’s time to do science! Our main objective of this cruise is to collect
samples of crustaceans from the ocean to study their bioluminescence. However, marine organisms of the deep ocean undergo an extreme vertical migration on a daily basis. You can read more about that here: During the day, with the sunlight shining into the waters of the ocean, creatures that rely on pitch black environments must dive deep into the ocean to escape the penetrating rays of the sun. That means we need to extend our net lines deeper and deeper to catch them. It can take over an hour for our nets to reach the depths required, and just about as long to haul them in. For that reason, daylight trawls will be limited to one per day. Rather than waste so much time during the day, we’ll be doing most of our trawling at night, when the organisms we’re looking for will be much closer to the surface of the ocean, and much easier for our nets to reach.
Regardless, it’s time to perform our first trawl. We drop the nets….and wait. Our first trawl takes about
5 hours from dropping the net to hauling it back in. In the meantime, it’s more of the same. Cards,
chess, sleeping, pretending you’re not sea sick… As we reach the final minutes of the trawl, we scamper to practice running through our tasks, making sure we understand what to do when the net is finally hauled in. As the net reaches the surface, there’s an air of excitement. What weird creatures have we pulled from the pitch black abyss?
The net is up! The very end is capped off by a long cylindrical canister. That’s where all the treasure is.
We empty the canister and immediately begin sorting through the catch. At first glance, our catch
seems minimal. There’s strange eels and fish, but where’s all the crustaceans? It’s not until we bring
the catch in for closer examination that we catch our first glimpse. Being adapted to the pitch black of
the ocean mean many organisms lack pigmentation. They’re completely see-through. It takes a keen eye to spot these tiny creatures.
After some very thorough sorting, we’ve got a respectable haul, but these shrimp aren’t what we’re looking for. They lack the photophores to produce their own bioluminescence. While we did catch some crustaceans, they aren’t our target. That’s how science goes, though. You don’t always score. With this site giving us poor results, it’s on to the next, where hopefully we’ll have much better results.