June 10th, 2021
Today was a highly anticipated day. Not only did we arrive at our next seep site after days of travel (plus a few stops to pick up plankton and then to pick up our chief scientist, Craig), but this is the deepest site on our itinerary. At 3300 m deep, Florida Escarpment sits at the base of a sheer underwater cliff. The unique sites We deployed Jason just after midnight. After a two-hour descent down the cliff, we reached a treasure trove of a site. Florida Escarpment contains Bathymodiolus mussels galore, a target species for many of us in the science party, as well as tube worms, sponges, and bacterial mats, spread out over a site which surprised us with its extent. We filled the slurp and the bio boxes full and spent several hours after exploring the site and recording video. At the site were a few indicators of human presence: some trash, which is disappointingly common at the seafloor, and some small collectors left by other science parties. We passed over some ballast weights left at the bottom from an Alvin dive when the vehicle prepared to surface.
When Jason surfaced around 3 in the afternoon, it was all hands on deck to sort and store samples. Mussels and tube worms were brought into the cold rooms in seawater, the sipuncollector and larval traps were recovered, and remaining sediment in slurp chambers and bio boxes were sieved and stored for the long process of larvae sorting. Laura, a WWU master’s student studying hydrothermal vent bacteria, was presented with her own bacterial mat sample for sequencing. During the chaos of unloading Jason, the TGT crew also assisted in deployed Sentry on its second Florida Escarpment dive for yet more larval samples.
Meet a Scientist on Board
Hello blog-goers! My name is Avery Calhoun, a PhD student in Craig Young’s lab at the Oregon Institute of Marine Biology (OIMB), University of Oregon. My background lies in mapping, habitat modeling, and community ecology. I studied Marine Science at California State University, Monterey Bay (CSUMB), and I am excited that the Arellano lab brought along Liam, a current student at CSUMB. It has been great to catch up with him and get updates on my favorite professors (hi Gerick and Alison)! My project in the Gulf of Mexico focuses on species associations and habitat modeling for organisms at methane seep sites with the goal of determining physical conditions that may contribute to distribution of larvae. While I am gathering information for my dissertation, I am also working closely with the Sentry AUV and Jason ROV teams to prepare coordinates for our dive sites and surveys. The Sentry team shares a lab space with our science team which has promoted great networking and social interactions; I look forward to working with them throughout my career! Fun fact: I’ve caught and released 2 stray stowaway birds from our lab this trip.
The rest of the day was spent sorting larvae under microscopes and dissecting bivalves. Both operations take lots of time, so the science party has been keeping busy. This site had a lot of samples, finding ourselves with 18 containers of slurp and biobox sediment to sort through. We hope to have all of our samples processed by the time we reach our next site where we can do it all over again.
The Florida Escarpment site is one of our more charismatic sites, with fascinating topography and communities. Here’s a video that Avery Calhoun put together on the Alvin cruise last spring from the footage at this site!