Most of the lab came to the GSA meetings. Dr. Garey, Madison, Christina, Bobby, Vickie. All made the trip. Dr. Garey and Christina made oral presentations on Sunday, while Madison, Bobby and Vickie did poster presentations. We visited Pike's Market, went on a Ferris wheel, saw the Space Needle, and wandered around beautiful downtown Seattle. The first day was rainy but it has been cool and sunny Sunday and Monday. We met a lot of people doing interesting research in karst.
We visited Double Keyhole Spring located on the west coast of Florida. The Spring discharges into the Gulf and we have published several papers describing how this spring creates an "invisible" estuary that is a sensitive ecosystem supporting juvenile fish. Vicki is running a carbonate dissolution experiment begun by former student Rachel (now graduated). It is a long term measurement of how fast carbonate dissolves in a variety of conditions. This experiment is in its third year. Carbonate dissolution is what enlarges conduits and creates sinkholes and other karst features over time.
We drove to Aripeka, put the boat in the water and motored several miles to Double Keyhole Spring. Bobby and Dr. Garey made the dive with Vicki there to help with the boat and handle the samples we collected. The experiment is set up in a shallow conduit that is about 8 feet in diameter back in about 200 ft at a depth of 25 ft. We collected one set of microcosms (pvc tubes with sorted limestone gravel) and also collected biofilm from rock surface and from the pvc frame that holds the microcosms. Finally, we collected sediment and water samples. It was a lot of samples and we did it in two 45 minute dives. Then back to the boat, back to the dock, and back to USF and another long night of sample analyses with all the lab members pitching in.
Bobby and Dr. Garey made their first post-hurricane Irma dive on Tuesday October 3rd. The flow was as strong as we have encountered and it took a major effort to get in, especially with all of the sampling gear and instrumentation we had to carry. Luckily there is a thick rope tied of inside the cave along the right side as you enter, which helps when you can't simply swim in. Once we got in to where the cave opens up, the current drops off and we proceeded to our instrument station about 300 ft in at a depth of 80 ft. We swapped out the ADV and Hydrolab and went to our 90 ft deep sampling station about 20 feet further in the cave. There we collected water, sediment and biofilm samples. Total dive time was about an hour. Then the students pulled another long night analyzing all the samples. It is a lot of work on dive day!
We visited Hospital Hole to collect samples for Madison's project on September 28th. Bobby and Dr. Garey went as divers while Madison and Chelsea did boat support, surface sampling and took care of all the samples. It was a beautiful Fall day. Hospital Hole is a deep sink (140 ft deep) located in the Weeki Wachee River in Florida. Normally the deep water is anoxic with the walls at the deepest point covered in biofilm. This soon after Hurricane Irma there had been a change and none of the normal biofilm was found in the deepest part. However, on the way up we passed a normally inactive vent that was discharging water at a tremendous rate and it was surrounded by various types of biofilm. Luckily we had spare sample bottles and made a second dive to collect water and biofilm samples from the vent. All went well, we returned to the lab and all the students were up much of the night processing all the samples. We expect some very interesting results.
On Tuesday, we visited Jewfish Sink, a site we have been studying since 2003. It is located in the Gulf of Mexico about half a mile offshore, a mile south of Aripeka, FL. The sink is about 200 ft deep. See Garman et al. 2005 and 2011 for details. The purpose of the dive was to collect sediment, water and wall biofilm samples from the deeper anaerobic portion for Madison and Chelsea's projects. Bobby and I made two dives. The first was down the center of the sink to the debris mound at 154 feet where we collected sediment. After a one hour surface interval we made a second dive along the eastern wall to 112 feet where the biofilm is particularly thick and we were able to collect plenty of biofilm with large plastic syringes. We also collected water column samples. Although the surface water is well over 80 degrees this time of year, the deep water in the sink was only 66 degrees so we were glad to get into the warmer water for decompression. One of the things we want to see is how similar the microbial communities in this offshore sink might be compared to those in similar saltwater coastal sinks found on shore. Madison and Chelsea provided boat support. It was a beautiful day, glassy smooth with no wind. There were dozens of dolphins feeding in the area and we saw a number of large rays and sea turtles as well. We left the lab at 8 in the morning and returned around 6 at night. All the other students were in the lab when we returned to help process the samples well into the night. It was a fantastic day and a successful trip!
As I write this, we are waiting to see where Hurricane Irma will be heading as it will likely have an effect on the lab's activities next week. Hopefully all will be well.
Bobby Scharping and Dr. Garey completed a dive in Hudson Grotto yesterday. The goal was to bring a full set of samples from the deep section (132 ft deep). It was Bobby's first scientific dive using a rebreather. We dropped down to the bottom of the grotto and headed to the south wall, and turned left until we found a section of wall with extensive microbial mat. Although the surface water was 89 degrees, the bottom was 74 degrees in this anchialine system. We collected a water sample for stable isotopes, and then filled 9 syringes with microbial mat samples from the wall. After that we moved a few meters away to avoid the sediment we disturbed and collected water column samples, and finally, some sediment samples. We spent another 30 minutes or so decompressing and making our way to the surface. Once we arrived back in the lab, Madison, Vickie and others were there to process the samples and carry out the chemistry tests and DNA extractions. So it was another great day!
Thanks to graduate student Christina Moss, we have a new Garey Lab website. We are trying out a blog to keep interested folks up to date on the lab activities. Now in early August we are planning a dive next week to Hudson Grotto to collect some deep microbial mat samples for Madison Davis' project. Other than that, lab members are catching up on LH-PCR and qPCR runs and analyzing some Illumina sequence datasets collected earlier this year. I include a photo of a lab meeting in the office taken late last year.