Same thing we do every night, try to take over the zoooplankton world.
For the last few days we have had a pretty intense sampling program. The zooplankton stations were spaced about 90 minutes apart. That is not a lot of time to sort through the catch! I I have been exhausted. Now we are in a part of the sampling area where the stations are 3 hours apart and I can take a moment to show you what we have been up to.
We were working west of Elephant Island and this area is dominated by T-mac, tiny tiny T-mac that take forever to pick from the sample trays. One day I picked 462 T-mac from one haul, not to mention what everyone else picked!
You remember T-mac? They are a small euphausid (related to krill), with kidney bean shaped eyes. They are pretty easy to identify in the sampling trays, so I can pick them out pretty quickly.
T-mac are very very very abundant. They are everywhere we sample. Even in the samples with lots of krill there is lots of T-mac. Yet despite this abundance, relatively little is known about their ecology. Antarctic marine ecosystems are thought to be krill centric; lots and lots of animals eat krill. Studies of whales and seals and fish and birds have all found lots of krill in their poop and bellies. Yet T-mac is super abundant and is found everywhere. Surely it has an important role in the ecosystem. Surely lots of critters eat T-mac. T-mac must also be a huge consumer of algae. Yet no one has described T-mac’s ecological role yet.
Mixed in with all the T-mac we have found some interesting critters like these guys…
We have caught some really cool amphipods. I love these Eusirus because they were so huge. The top guy filled my hand (no macro lens kit required!). The photo doesn’t really do them justice. They were bright pink with yellow and green. So pretty and cool looking!
Some of my favorite critters are the little shell-less snails known as pteropods (you don’t hear them coming because the p is silent). One of the most common ones we get is Clione limacina. It comes in shades of pink orange and yellow. We got some very large ones recently. When they swim up to the surface it looks like they want to kiss. They are so cute!
The little dumbo ear flaps you see are just a specially shaped part of the snail’s mantle. They are not the most graceful of swimmers, but they are pretty cute.
Another one of my favorite zooplankters is the chaetognanth (or arrow worm). This thing is a fierce predator. It will often try to eat things while we are looking at it through the microscope.
Cheatognaths range in size from microscopic to several inches long. Whatever size they are, they are pretty badass.
We also have a lot of larval (baby) fish that get caught in the zooplankton net. Some look right out of the movies.
Some of the larval fish are so odd that they can’t be found in any of the reference books we have on board. It’s a good thing the fish team likes a challenge
We also catch quite a few fish eggs. Where did you think the larval fish came from?
We are doing some daytime trawls for fish and larger benthic creatures. I guess I better get ready for that.
Catch ya later.