Chelsea Dinon has had a very busy week. Her project is an investigation of how well aquifer microbial communities can remediate nutrients and contaminants in reclaimed water. She went to a wastewater treatment plant to pick up the reclaimed water, stopped off at Sulphur Springs where she and Bobby collected aquifer water from the entrance to Sulphur Springs and then spent an intense week of setting up more than a hundred microcosm experiments, and analyzing the hydrochemistry of subsamples every few days. It was a lot of late nights with the entire lab helping. She will be spending the next week extracting DNA for 16S rRNA microbial community analyses.
Madison Davis, Bobby Scharping, and Dr. Garey visited Jewfish Sink, about a km offshore from Fillman’s Bayou near Aripeka Florida. The goal was to get deep water column and sediment for Madison’s three sinks project where she is comparing the microbial communities and hydrochemistry of Jewfish Sink, Hospital Hole, and Hudson Grotto. This is the last set of samples she needs for the project. We saw dolphins, sea turtles and most specially, a Goliath Grouper. You may know this is the largest species of grouper and can weigh in at more than 700 lbs and grow to a length of 8 feet. They are a protected species that used to be called Jewfish, hence the name Jewfish Sink. The Garey Lab has been diving Jewfish Sink for about 20 years and yet this is the very first time we spotted a Goliath Grouper in the sink. It was somewhere around 5 feet in length and just cruised through the shallow throat of the sink, about five feet in front of us, probably looking for the mangrove snapper and sheepshead we had notice earlier.
Five members of the Gareylab visited San Salvador island in the Bahamas March 12-17 2019. This was our 3rd trip in 5 years. We went with Dr Bogdan Onac with a group of Geoscience undergraduates for the field karst course. Madison Davis, Bobby Scharping, Chelsea Dinon, Meghan Gordon, Josie Knieriemen and Dr. Garey were there. We learned a lot about the karst geology of the island through 5 days of field trips and focused on a continuing project studying three blue holes at the south end of the island: Inkwell, Church, and Watling’s blue holes. Bobby and Chelsea placed the ADV and Hydrolab in Watling’s Blue Hole while Dr Garey and Meghan collected water and sediment samples at Church Blue Hole. On the second day of diving, the entire lab participated in a thorough sampling of Inkwell. Along with the hydrochemistry, we will be doing microbial community workups on the blue holes to follow up on a manuscript currently under review from our last San Salvador trip.
Bobby Scharping and Dr. Garey have been working their way through the Weak Spring tunnel, a small side loop of the main tunnel. The original guideline was broken and the passage is very constricted and silty, so we have been laying a new line, slowly working our way to where there is yet another passageway that leads to a couple of very interesting rooms with unique hydrochemistry and microbial communities, and even some stygobitic arthropods. No one has been in this part of the cave in over 20 years. We reached the old T in the line, and so to our right was the room of interest, and to our left the continuation of the tunnel that leads back to the main conduit. Turning right we went up a very steep and silty sediment mound and found a shallow room filled with huge biofilm growths, like giant gray icicles that were inches thick and up to several feet long. Proceeding to the right we reached another area where there was a rock ledge that appeared to be containing a cloudy chemocline layer. We then headed back to the main conduit, picked up some equipment we had deployed in the Fall, and exited the spring. On the next trip we hope to collect some of the stygobitic arthropods for stable isotope analysis and confirm that we have good guidelines through the entire weak spring tunnel.
The USF Cell, Molecular, and Microbiology Department hosts a seminar series on campus throughout the semester. The lecturers range from Nobel Prize winners to Professors to PhD students. Madison, one of our PhD students, gave a seminar on her research on Florida sinkholes. She has found that the three sinkholes she is focusing on—Hospital Hole, Hudson Grotto, Jewfish Sink— have unique microbial communities despite all being linked to the Upper Floridan Aquifer.
Good Job Madison!
Dr. Garey and Bobby dove Doublekey Hole springs this past Sunday in hopes of reaching the “big room” about 1350’ into the cave. We are hoping to study the saltwater/freshwater interface in this room because we believe it creates the prefect redoxocline for chemolithoautotrophic bacteria. Unfortunately, due to a strong current, they weren’t able to make it all the way back. Dr. Garey and Bobby were happy to get back in the water after a a couple of months of no diving, however, and were still able to collect some samples for iron chemistry analysis. It was a beautiful day to be out on the water, and the group even got to witness a pelican and a dolphin fishing from the same school of mullet on their ride back in! We will be back soon, and will hopefully get to reach the big room next time.
A big thank you to our undergraduate Kim for snapping some great shots of the day!
Bobby Scharping gave a seminar on Sulphur Springs this morning as a part of a series put on by the Cell, Molecular, and Microbiology Department at USF. His work examines the anthropogenic impacts of seawater intrusion, how it changes the cave's microbial ecology, and what those changes mean for the Hillsborough River.
The lab recently travelled to the Canary Islands to present our current research at the 4ISAE. Bobby presented on his seawater intrusion model from Sulphur Springs and Madison introduced a microbial ecology perspective on Hospital Hole that this research community had never previously been exposed to. Chelsea and Meredith also attended the conference and participated in the poster session for their respective projects, Hudson Grotto and Crab Creek Cave. In addition to presenting and attending seminars, the lab got a chance to explore the island and witness a landscape that produces one of the worlds largest lava anchialine systems.
On Tuesday, we went to Madison’s site, Hospital Hole, to collect water column samples from each water layer. Bobby had visited Hospital Hole for fun about a month ago and discovered two new vents that we were going to check out. The Hydrolab indicated that these two vents expel water from the same source. The vent at 77’ was covered with mats of white filamentous biofilm! (video to be uploaded). We sampled the biofilm for microscopic imaging and analysis. Our MS student, Chelsea, was also able to get in her first scientific dive! We had a flat tire on the way back to the lab, which made for a late night performing water chemistry. But thanks to the help of a couple volunteers, everything went smoothly. Overall, a long, but successful day!
We did a field trip to the Chassahowitzka River Sunday morning of July 29th to support Meredith and Bobby’s project on the Crab Creek Springs. We met at the lab a 6 AM and had the boat trailer and all the gear loaded up and out the door by 6:30. We launched the boat around 8:15 and were on site at 8:30. There is a wide creek that feeds into the Chassahowitzka that is fed by a number of springs, so we were picking up some instruments we had left in those springs in April and went in one of the springs to get samples. It was a small underwater cave with a tight restriction that we wriggled through, then down a passage to a beautiful little underwater room where we spent about 30 minutes collecting samples. there were even some stygobitic amphipods swimming around. It was a great day.
It has been a busy year and we have been diving nearly every week to keep up with all the projects in the lab. Last week we dove Sulphur Springs to exchange some instrumentation that had been in the spring conduit since November and to get some much needed samples. This week we went back to Hospital Hole. For the first dive we dropped a bucket of cement as a weight tied to a line that connected to a surface buoy. You can see the buoy in the photo below. It immediately attracted all the manatees. Bobby and Dr Garey went down the line, measuring the distance from the line to the wall using a hand held underwater sonar device. We determined that the hole is about 50 ft across at the top, and about 130 ft across at the bottom. We removed the bucket and buoy at the end of the dive. On a second dive, we did some exploratory diving, documenting many of the smaller vents and odd patches of biofilm. It was a cold day and Madison did a great job providing boat support.
We went to Hospital Hole to collect samples for Madison's project. It took all day as Roger's Park is still closed and we had to launch the boat at an alternate site several miles down river. Bobby and Dr. Garey did three dives, collecting water, biofilm and sediment samples from a number of locations at depths of 40-130 feet deep. Madison did boat support and took care of all the samples. The manatees were in full force. In the winter they leave the chilly water of the Gulf of Mexico and come up the spring-fed rivers where the water is always 74 degrees F. Usually in the winter there are several families of manatees present around Hospital Hole. Back at the lab, everyone had a very late night doing all the water chemistry measurements.
Our last dive of the calendar year was to Jewfish Sink, a deep sinkhole located about a km offshore, just south of Aripeka, FL. We left the lab around 9 AM and arrived at the Aripeka boat ramp at about 10:30. The tide was low so we had to be careful maneuvering out the channel. It was slightly foggy at first and we saw a terrific fog bow just after we left the ramp. It became a beautiful day with glassy smooth water and we saw a couple of sea turtles and some small bonnet head sharks along the way. We anchored at the hole and Bobby and Dr. Garey suited up with Vickie doing boat support. Gulf water was 65 degrees F and. the air temperature was about 75 so a bit chilly for us Floridians. The first dive was along the wall down to the anaerobic zone where we collected water and biofilm samples at about 110 ft. The hole is about 18 ft across at the surface but gradually widens to about 200 ft wide, so the divers had to swim back under the overhead as they headed toward the wall. After a bit of decompression and a good surface interval, the second dive followed a line we had left on an earlier dive. This line terminates on the debris mound at about 160 ft where we collected sediment for Madison's experiments. At that depth there is no light, no oxygen and a lot of hydrogen sulfide. All went well and we had a great trip back to the dock, and again, a long night processing samples.
We visited Double Keyhole Spring to harvest the first set of microcosms for Vickie's senior thesis carbonate dissolution project. We left the lab at 7 AM and arrived at the Aripeka FL boat ramp at 8:15. It was a beautiful calm cool day. We launched the boat and motored to the Spring with a bunch of dolphins riding our bow wave part of the way. We arrived around 9:30 and were in the water a little after 10 AM. High tide was at noon, and we have to collect water samples an hour or two prior to high tide as the tide can cause the spring to reverse flow. We need to be sure the water we collect is from the spring and is not Gulf water brought in with the high tide. The goal was to bring one set of 12 microcosms out along with a full set of water samples, sediment samples, and microbial mat samples from the wall of the conduit. The microcosms are pvc tubes containing crushed limestone. It took Bobby and Dr. Garey a little over an hour to collect all the samples but took all night for the lab members to process them all once we got back to the lab.
The lab visited Hospital Hole in the Weeki Wachee River to obtain samples for Madison. Dr. Garey and Bobby made the dives with Madison in charge of the boat and sampling strategy and sample processing. Hospital Hole is a highly stratified sink located under the Weeki Wachee River near Weeki Wachee Gardens in Florida. It takes about 90 minutes to get there from USF. Our normal boat launch site is Roger's park which was closed for some parking lot resurfacing so we had to go to another park further downstream. Once we launched it took about 30 minutes to reach the site. We hit the water around 1:30 PM and made a series of dives. We collected water from the overlying river, from the hypoxic zone, an active vent in the hypoxic zone, the chemocline, and the deeper anoxic zone. We also collected biofilm from some zones and sediment from the bottom. In total we filled about 50 sample bottles. It was getting dark when we headed back and there was a beautiful sunset along the river. Then the students pulled an all nighter in the lab getting all the samples processed and all the tests run.
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.