Marine Biology Story of the Day #8
Before I start in on this one I would just like to say how all of your reblogs and likes totally make my day—thanks so much for the support! I put a lot of effort into these so they read well!
Okay, so as promised, this is part 2 of what it’s like to live on a working tallship. You can check out part 1 and other information about this voyage here: post 7 and post 1 . Today we are going to talk about what it’s like to do science on a sailing vessel. Our baby was the Robert C. Seamans, a 134 ft brigantine.
We were limited to what we could research-wise do since a sailing vessel does not have the same power as a modern vessel with an engine. We were mainly researching plastic concentration (from trash and garbage that gets released into the ocean) in the north pacific subtropical gyre. A gyre is basically a big ocean current, and they tend to concentrate plastic and garbage into central regions (shown below) we were studying the garbage patch off the California coast.
We did see a lot of large plastic, mostly in the form of in-tact plastic containers, buoys, or derelict fishing gear (known as ghost fishing, because this gear continues to catch and kill fish even though no one is benefiting from it).
But, in actuality, most of the plastic found in these patches is nano or micro, basically little pieces that have broken off of larger pieces and get worn down by the wind and the waves. This also includes little pieces of fishing line (monofilament). These pieces are often more dangerous because very small organisms (including plankton!) can swallow them, and the plastic can rip up their insides and release harmful chemicals.
How did we sample for this micro plastic? The same way we did plankton! We used a net with very very fine mesh called a neuston net, which we towed along side the ship, and then we filtered the water into increasingly smaller sizes of mesh. After that, used a microscope to sort and count plastic, and to identify species within the plankton community.
We caught a lot of interesting organisms and species in these tows, including these types of zooplankton below:
Top row: Copepods and amphipods, which sort of form the bottom of the food chain out in the open ocean, Bottom left: pteropod, or a swimming snail, these guys have modified their “feet” to form wings that the flap to get around in the open ocean, Bottom right: velella velella, or by-the-wind sailors, are siphonophores (similar to jellyfish) that use their big sail to push them around the surface of the ocean.
We also caught a variety of larger organisms, including flying fish (which are a real treat to see IRL, they really do glide for hundreds of feet) and various species of squid.
We also collected water samples. Water temperature, salinity, and dissolved oxygen are all important parameters that help us understand why certain species live where, and how climate change could impact these species habitats and ranges. We used a hydrocast (shown below) to do this:
A hydrocast has multiple canisters that are all opened before the hydrocast is lowered down, and each cannister is programmed to snap shut at a different depth. This way we could collect water samples at a variety of different depths, all the way down to the sea floor.
We also sampled at night to collect deep sea plankton and fishes as they migrated up to the surface to feed (called diel vertical migration). During the nighttime, there are less predators, so it’s more beneficial for them to come up to the surface and access the nutrients and phytoplankton on the surface. If you want to check out some of these deep sea critters, check out my previous post! In the meantime though, to pass time, we would sometimes fish for squid. This involved shining a light down in the water to attract the squid, and then throw baited handlines down in the water—we were not often successful.
We were more successful at fishing for tuna and mahi mahi however, during the daytime. We would throw a baited line off the back of the ship while the ship was running at full sail. These fish would get fin clips for genetic studies, and would also get turned into some pretty boss cerviche, poke, and fish tacos (our stewards, or boat chefs, were AMAZING). Don’t worry, we didn’t catch too many of these guys, but they were still pretty cool to see up close and in person.
Left, A mahi mahi, (or dolphinfish or dorodo, depending on where you come from) slowly loosing color; these fish die pretty quickly out of water, and they quickly become grey, loosing their bright blue and yellow coloration. Right, a skipjack tuna; these are one of the smallest tuna species and are usually considered trash fish—the endangered bluefin and yellowfin tuna are like, bigger than a person. It will blow your mind.
One last thing before we go—by the end of the trip they started letting us, the students become the chief scientist during our watches, which was an amazing learning experience, and we were bestowed the magical tutu of chief scientist-dom (made out of a torn neuston net).
This picture of me was taken in the science lab when we officially hit 1000 nautical miles into our journey—at 3 am in the morning. Yes, being a scientist was a 24 hour job on this trip, if you couldn’t tell from my dark circles.
Alright, well that’s about all I have for today. Next week I’ll reveal to you all what I do as a marine biologist currently, and while I’m no longer sailing on the pacific, I’m still doing big studies---and this time, they are all
And as always, PLEASE don’t hesitate to ask about this research or anything else on this trip!
