Boating the Canal

Today was such an incredible day! We started off by going to a field site we had visited last week, near the neighborhood of San Judas. The rock there is part of the Gatun Formation, which dates to the early-late Miocene, maybe around 9-8 million years ago. It's another one of those sites that is just overflowing with mollusk and gastropod fossils, but there are vertebrate remains to be found too if you're eyes can pick them out amongst the endless shells. I had a terribly hard time finding anything interesting, whether by lack of skill or lack of luck, and by the end of the afternoon my collection bag was looking depressingly empty (see photos). I thought I was on to something big when I found a sizable piece of wood (maybe five inches across in the longest direction) within a cliff face, but after pulling it out I realized that it was entirely carbonized (basically turned to charcoal) so none of the original textures and features remained. I did make it out with a few fish teeth and ray plates, but nothing compared to the two-dozen or so shark teeth that everyone else collectively found. You win some, you lose some. And it was a beautiful sunny day with a steady breeze, so I was far from being down in the dumps.

Nicole's shark teeth

My meager findings

Carbonized wood (it was big!)

Our vessel

We got back to CTPA (my department) just before 3:00 PM, giving us just enough time to grab a snack and clean up before heading to a Smithsonian-sponsored seminar on Barro Colorado Island in Gatun Lake (park of the canal route). Barro Colorado became an island when the area was flooded during the creation of the canal and is where the Smithsonian set up its first station in Panama. The high biodiversity and isolation of the island make it the perfect place for ecology research, and a lot of famous work has come out of the area. To get there, we drove out to a town called Gamboa that sits on the canal a few miles southeast of the lake and caught a STRI boat that then ferried us to the island. A water delivery had to be made, so they put us, along with the other eight or so passengers, on a larger boat than is usually used and we were able to sit outside on the deck. By about half an hour before dusk, we were out on the canal watching the sun set. It was unbelievably beautiful! Before even getting to the island I knew I wanted to go to every single one of these talks just for the journey there!

The other interns, from left to right: Pedro, Sam, Nicole

First thing as we were stepping off the boat, we saw a caimin (a type of small crocodile) hanging out on the shore and a couple of bats flying around between the buildings. We were served dinner in the cafeteria there, given some relaxing/socializing time with $1 beers, then led to one of the center's conference rooms for the lecture. The talk was about gene flow and adaptation (mostly to climate) in crustacean species along California's coast. The general idea was that animals that fix themselves to a substrate (i.e. barnacles) can only live on rocky beaches/jetties where they have something to cement onto, but these areas are frequently isolated from one another by large stretches of uninhabitable sandy beaches. Nonetheless, the same species are seen throughout the coast, so obviously are able to distribute during their larval, free-floating/swimming stages. The question then, was to what extent genes are exchanged and how much homogenization occurs within these kinds of animals. The speaker went on to show that it was actually fairly limited and further showed that different populations expressed different genes to deal with the same environmental changes like temperature and salinity. The point of all this is that these animals seem to have a large pool of strategies to draw from when dealing with shifts in climatic conditions and therefore are likely much more tolerant to change than previously thought (bodes well for future climate change). There was much more to the talk, but the speaker kept referencing a talk he had given earlier in the week (which I had not attended) and saying things like "you all know this by now..." (when I didn't) so a lot of it went over my head. Confusion aside, the overall trip was incredible and I will doubtless be returning at the next chance I get.

Oh, and interesting fact I learned yesterday: whales have asymmetrical skulls so that the sound impedance is different on either side, allowing them to hear directionally under water!