Feed Me, Artemia

Welp, our experiments with the Tetraselmis have come to a conclusion. I haven't computed the data yet, and will update this post as soon as I do, but based solely off of visual observation, it seems as though these cultures reacted to the levels of oil in the same manner that the Thalassiosira did (with the middle amount of oil yielding the smallest cell density). While neither Mr. Soderblom nor I have come up with any solid conclusions as to why this happens, I will be emailing the GoMRI (Gulf of Mexico Research Initiative) to see if they perchance have noticed similar patterns in their research and hopefully have some theories by the time next week rolls around.

But the reason I'm so anxious to post despite having no data yet is that this week, Mr. Soderblom and I came to the conclusion that it would be fun to see how zooplankton react to the contaminated phytoplankton, which is something we originally thought I might not have time for! (Yay!) This section of experimentation will lend an insight into how the oil gets metabolized as it works its way up the oceanic food chain and help me to better contextualize the reactions of the phytoplankton cultures.

The species of zooplankton we have used are called Artemia, or in layman terms, Brine shrimp. They're pretty big, about five could fit on my nail (approximately 8-12 mm depending on age and sex), and very creepy. Their nearly translucent body allows me to see both of their compound eyes at all times, no matter the direction they're facing. Their bodies are covered with a thin exoskeleton and have a total of 19 segments, 11 of which house pairs of appendages that move a way that reminds me of millipedes, if millipedes could swim. The Artemia species is believed to have existed for about 5.5 million years. They're used for toxicology assays, aquaculture, and have even been launched into lower orbit to see how radiation impacts life (they were taken on a total of 7 missions guys). Below are pictures starring them, the first being from our own experiment, and the rest from Google.

As you can see in the first picture, we put about twenty in each tube. Then, half of the solution they're swimming in is their own water from their previous holding tank. The other half is from the phytoplankton cultures. We've filled ten test tubes, four controls, and two of each level of oil (so two tubes containing the culture with 1 drop of oil, etc.). I believe the zooplankton will react similarly to the phytoplankton with accelerated growth rates, but we'll just have to see.

Signing off till next time, this is Erin Butcher.