Tracking migrations through fish scales: Update

Hello all! So after the initial rush to prepare my scale samples for stable isotope analysis  during the first two weeks of the project, the work for my specific project has slowed down as we wait for our results to be sent back to us to analyze. In the mean time I have been assisting in some side projects in the lab. One of the projects I assisted with was removing some scales, tissue samples, and the otoliths from a large deceased tarpon specimen we received from the Texas State Aquarium in Corpus Christi. That was really exciting because I had seen otoliths we had removed from smaller tarpon and was really interested in how large the otoliths in the large tarpon would be. It turns out that they were not much larger than those from the smaller tarpon, despite the large size difference in the fish themselves. They were really hard to find because they were embedded in cavities within the bones of the fish’s head. Now that we have found them, we have them stored away for future analysis. This past Monday, I went with my graduate adviser, Matt, and another REU, Cypress, to the Texas State Aquarium to take water samples for trace element analysis. It was extremely fun because we got to go behind the scenes and see much of the equipment used to keep the tanks in the aquarium up and running. Taking the water samples was a bit rough because of the strict protocol I had to follow to prevent contamination. The water had to be passed from a syringe through two really fine filters into the sample vial. In order to pass the water through the filters, I had to press really hard. Let it be said that my thumbs got a really intense workout. However, after we finished taking the samples, we got to tour the entire aquarium! The Texas State Aquarium has so many cool exhibits, my favorite of which was an estuarine exhibit featuring a number of birds native to the gulf coast, including my absolute favorite the roseate spoonbill! There were also a number of other cool exhibits simulating coral reefs and the rivers of the Amazon rainforest! It was such a fascinating experience!

In the coming week, Matt and I plan to go investigate this ditch in Aransas Pass where some local fisherman have informed us that some juvenile tarpon have been found. We plan on bringing a seine and trying to collect some live juveniles to bring back to FAML and use  for some experiments regarding scale growth and incorporation of trace elements and stable isotopes in response to different salinities. Wish us luck! Aside from that we will be taking some more otoliths out of some juvenile tarpon specimens we have, and analyzing trace element data we have on our scale samples to prepare us for when we get our stable isotope data back.

Life in Port Aransas has been incredibly fun too! I spend most of my free time after work walking the jetty watching an absolutely insane number of sea turtles and dolphins pop their heads up out of the water to breathe, going to the beach to see what critters I can find close to shore (my favorite finds have been a striped burrfish and a bunch of Atlantic ghost crab megalopae), and during low tide looking at the shallow water in a salt marsh from a bridge on the MSI campus to see what kind of crabs and snails I can find. I’ve also went with my REU friend, Cypress, to Charlie’s Pasture, a local nature preserve, to hike around and look for cool birds. My favorite thing I saw was a black skimmer feeding really close to the tower we were observing from. I also saw a roseate spoonbill in the distance, but it was too far for me to make it out as anything more than a pink dot. I hope to go back again so I can see one in more detail! I’m so excited for this weekend because this Saturday is the Fourth of July! I’m betting that the firework show on the island is going to be magnificent, and it will be really cool sharing that experience with all my friends I’ve made here at MSI this summer!

For your viewing pleasure, here is a picture of me holding this ridiculously large tarpon specimen (prior to dissection) I was talking about earlier in my post.

holding a tarpon

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