Day 10: Best Day Ever!

Hello everyone!!

My name is Elsa and I am a recently graduated senior with a BS in biochemistry. I am a part of Team ATP on this trip. My partner Liya and I are working to measure ATP in various bodies of water which can help us infer the levels of living biomass in the oceans, bays, and lakes. Although this could be said literally every day here, today was the best day ever!!! On this leg of the trip, I am working with team FRESH. We have a couple of connected projects that we are working on. First, we are characterizing some freshwater lakes that are located on different motu within Tetiaroa. We do this by sampling every parameter at each freshwater lake on a different Motu. This includes ATP, chlorophyll-a, nutrients (phosphate and nitrate), pH, DIC, alkalinity, temperature, and salinity. Secondly, we are testing the effect that the seabird populations have on nutrient levels in surrounding waters. We are sampling from Motu with different bird densities and comparing the data. This will give us an idea of how bird guano affects the biology and chemistry of the ecosystem in this atoll. 

Now enough about the background of our projects… Let's talk about what I did today! Team FRESH ventured out to two different Motu today. The first was Tiaraunu where we found a variety of creatures including coconut crabs, pufferfish, a sea turtle, and a baby black-tipped reef shark! The wildlife in Tetiaroa is so unique. If you want to learn more, you should visit the Tetiaroa Society website. On this motu, we were guided to the fresh water well in the center of the motu. We learned that this is where fresh drinking water is filtered and treated from and a little bit about the process of this. There are pipes that run underground between the two Motu. It is completely autonomous, which is super fascinating. We sampled this water (pretreated and post-treated) and sampled along the beach before heading back to Onetahi. 

Later in the afternoon, we boated over to Rimatu’u in the longest boat I have ever seen. This motu has been my favorite so far. Rimatu’u is connected to “Bird Island” which has an extremely high density of seabirds, but we couldn’t get too close to Bird Island today because of the Brando guests going on tours – we have to steer clear. On Rimatu’u we sampled the water on the beach and then we went on a little hike into the palm tree forest where we found two freshwater lakes, a smaller one (Le Petite) and a larger one (Le Grande). Both had a layer of microbial mat on the floor. This was very exciting for us as we expected to find a lot of nutrients from these mats. DLo grabbed a chunk for us to see the distinct layers of the mat which was so cool. See the pictures attached below!

After our sampling journeys, we returned to Onetahi to analyze our samples in the lab, hangout, and eat some dinner. We ended our night hanging out at the local beach bar “Baps” and stargazing. As you can probably imagine, the stars here are absolutely incredible. I have been having the most amazing time on this trip, and I can’t wait to see what the rest of French Polynesia has in store for us.

Thanks for following along with me today!

Elsa