Category Archives: 2023 Mitchell AAUS

Jack Hamilton

Who Lives in Panama Under the Sea? Sea-Sponge-Reef-Inhabitants!

On July 19th I began the second half of my journey as the 2023 American Academy of Underwater Science (AAUS) Mitchell Scientific Diving Research Intern for the Our World-Underwater Scholarship Society (OWUSS). After departing the Florida Keys I headed back home to switch out my gear and prepare for field work in Central America.

I began by flying from Boston to Miami—I did not expect to be back in Florida so soon. After around three hours of delays due to lighting strikes, I was finally able to board the plane. Once the plane was fully boarded, we were all informed by the pilot that “the plane needs a new lifeboat, and we would not be able to take off until they found one” … what happened to the first lifeboat still remains a mystery.

Finally, I made it to Panama City, Panama where I met up with my team at the hotel.

View from our hotel in Panama City, Panama.

The next morning, we headed out to a smaller airport near by to catch our passenger plane to the town of Bocas Del Toro. This flight lasted less than an hour, but had some beautiful views of the Panamanian countryside.

View as we land in Bocas Del Toro, Panama

Upon departing the plane, we were greeted by a kind man who sang to us as we waited for our bags—I later found out that he has been there since Bobbie started working in Bocas Del Toro back in 2019!

About half of our luggage was coolers that would hold the water samples we collect in the field on our return to the states—apparently customs and airport security were not fans the many large coolers we were taking into a foreign country, but it all worked out. We then loaded all of our suitcases into a taxicab truck—which I would come to learn is the only style of taxi in Bocas Del Toro.

We spent the next five weeks living at the Smithsonian Tropical Research Institute (STRI) research station just outside of town.

My bunk room for the next five weeks
View from the porch of the dorms

The station houses many different research teams and even some classes. There were teams researching corals, frogs, and even bats! Living at the station was an incredible experience—even if we were woken up by the resident howler monkeys at 4am.

The culprit of the 4am howling

The station also housed a ton of local wildlife!

The station had a supply of boats that would shuttle us to our coral reef sites, but we did not always need them. All the coral reefs we worked at while in Bocas were very shallow, and quite close to the research station. We often used kayaks or simply swam over to the sites to conduct our field work for the day.

Most days were started by a visit to one of our sites to either conduct a feeding trial (find out more about this in my first blog!), or surveys of the sponge community.

Getting ready to collect water samples from our sponge incubation chambers

A large focus while we were in Panama was these surveys. We assembled a surveyors grid at each of our sites for ease of analysis. The method is adapted from land surveying techniques. First, we measured the volume of three specific species within the grid which were the same species we used in our sponge feeding trials.

Once we measured the three species, we did a general percent coverage survey. The purpose of this survey was to quantify what organisms make up the reef community at each of our sites.

Sometimes the percent coverage surveys involved dodging large groups of jellies

Did you know that some sponges and anemones can be affected by bleaching events? We also conducted surveys of incidences of bleached or partially bleached sponges and anemones at our sites following a major heat stress event. I had been warned the water would be colder in Panama than in the Florida Keys but we knew something was wrong when the bay behind the research station felt like hot bathwater and not a cool dip in the sea!

A large cluster of bleached anemones at one of our sites

There was no shortage of lab work either… especially since the lab was the only place in the station with air conditioning. Lab activities ranged from measuring weight and displacement volume for sponge samples to operating the spectrophotometer for analysis of chlorophyll concentrations within the sponge tissue.

The U.S. Ambassador to Panama visited the station to check in on all the science being done

It is surreal that I have reached the end of my internship. The summer flew by so fast—but I guess that can happen when you are underwater for 4+ hours a day. I would like to thank the AAUS and OWUSS for this incredible internship experience and a huge thanks to my host Bobbie Renfro and Florida State University. I also want to thank the entire staff of the Keys Marine Lab and the Smithsonian Tropical Research Institute in Bocas Del Toro for hosting us throughout this summer. I look forward to presenting my adventure through the 2023 AAUS Mitchell Scientific Diving Research Internship at the 2024 annual meeting.


Out of the Water and into the Lab… and then into the Lab Again

On May 13th, I began my journey as the 2023 American Academy of Underwater Science (AAUS) Mitchell Scientific Diving Research Intern for the Our World-Underwater Scholarship Society (OWUSS) by boarding a flight from New Hampshire to Miami with the final destination of the Keys Marine Lab in Layton, Florida. With only a handful of warm water dives under my belt—warm water to me is anything above 55 degrees Fahrenheit—Florida was definitely foreign territory for me.

I will spend my summer focusing on coral reef sponge ecology research with PhD candidate Bobbie Renfro of Florida State University and her team. Bobbie is studying the effects of nutrient pollution on the sponges that live on coral reefs. Sponges play many super important roles in coral reef ecosystems! Sponges act as a form of glue, holding all the reef together, preventing erosion and helping living corals stay attached to the reef. Without sponges, reefs would not be anywhere near as storm resistant as they are. Sponges also are the habitat for tons of coral reef critters like brittle stars and snapping shrimps. One of the most important roles of sponges on the reef is their ability to filter the water. Sponges are able to create a strong current throughout their canal systems that actively pumps dirty water in and clean water out—acting essentially as a Britta filter.

After I picked up my comically large number of bags, I met Bobbie and her other undergraduate assistant Sydney. We drove from the Miami airport down to Long Key, and I got to take my first look at where I will be staying for the next 8 weeks. I got to move into the “Bay House” which was located off to the side of the Keys Marine Lab Facility looking out over Florida Bay! But my first day was not over yet, we headed down to the dock—sunlight was far gone at this point—to finish a portion of Sydney’s thesis project. The extent of my involvement of this was mainly holding up light so Bobbie and Sydney could see what they were doing in the water below, but I was excited to get started right away.

The day after was my first dive day in the Keys. I was very happy to shed my dry suit and 25-pound weight belt in exchange for a thin dive skin and 8 pounds. The water was almost double the temperature than back home for me! The majority of our dive work took place at one of our four coral reef sites, with half having poor water quality and the other half having good water quality to allow us to make explicit comparison of how nutrient pollution in the poor-quality water affected the sponge communities.

Our vessel for the next 8 weeks, the “Opah”

I completed four separate dives on my first day, mainly focusing on collecting samples for future projects. But not every day looked like this. We had a wide variety of projects we could be working on any given day.

Feeding Trials

The most prominent project was the “Feeding Trials” where we essentially looked at the filtration rates of different sponge species at all four of our sites. These involved two divers in the water setting up incubation chambers. Sponges were placed into these chambers, then we would extract samples at various time increments. The third team member was topside receiving, sorting, and filtering the samples. Each feeding trial involved five sponge individuals and one control. Approximately six feeding trials were conducted at each of our four sites total. This produces a lot of water samples!

Bobbie enclosing one of our sponges into it’s incubation chamber for the Feeding trials

Once the feeding trials have started, there is a decent bit of downtime as we wait to collect the water samples from each chamber; perfect time for some meditating

Sponge Survey

We also went on surveying dives where we measured certain sponge species within a permanently marked surveyors’ grid that Bobbie established at each site since 2019 and has surveyed annually since. How did we measure them? A lot of fancy underwater geometry.

Sydney and I setting up our survey grid which covers 30 meters2 of our sites. Once the grid is set up we will work in small quadrats until we have measured all of our sponges
Every once in a while we will get guests—like this Nurse Shark here—that decide to hang out in our survey grid, making it very difficult for us to complete our measurements

Sponge Restoration with I.CARE

Every Wednesday we got to work with our restoration partners at Islamorada Conservation and Restoration Education (I.CARE) and Key Dives to train recreational divers on sponge restoration. We head to the Key Dives shop early on Wednesdays where we would setup to give a presentation to recreational divers on everything you need to know about coral reefs and sponges! After the presentation, we gave a demonstration on the specific sponge transplantation techniques we would be using. After the demo, we would take the divers out to one of our restoration sites where they get to transplant sponges to the reef! We monitored the scientific integrity of the restoration work while I.CARE and Key Dives staff monitored the safety of the divers.

I.CARE Intern Courntey, Sydney, and I (right to left above) after a successful day of outplanting

The First Coral Reef Sponge Nursery in the Florida Keys!

One of the most ambitious projects we worked on was the assemblage of the first coral reef sponge nursery! We worked with Mote Marine Laboratory to set up this nursery at Mote’s Coral Nursery in Islamorada, Florida. First off, to set up the nursery we needed to collect hundreds of sponge samples to adequately stock it.

Bobbie briefing the nursery team with an on land demo before we head to the site

The nursery setup took place in one day and involved approximately 15 divers total from Keys dives, ICARE and Mote Marine Lab.

This project had so many moving pieces and seeing it all come together was incredible! I can’t wait to see how much the sponges grow over the next six months – Bobbie will calculate their growth in December and send me an update!

Out of the water and into the lab

After we finished up our dive activities, we head back to the Keys Marine Lab to unload the boat and clean our dive gear. Once the boat is cleared, we head to the lab to start processing our samples. We almost always have a large number of water samples that need to be frozen—this often involves a decent bit of Tetris in the communal lab freezers. Just as the diving activities differ each day, so does the lab work. On feeding trial days, the lab activities often involved weighing and calculating displacement volume of the sponges used for trials. Periodically throughout our time in the keys we took chlorophyll samples. This involved us collecting approximately four liters of water from one of our sites and pushing them through a filter which we would save at the end to analyze its contents. The chlorophyl in the water comes from the photosynthetic plankton and can affect how much light reaches the sponges.

Sponge samples taken from one day

Once we finished lab work, the days not over yet! Once we got back to the Bay house, we often had to start the setup process for our dive projects the next day. The night before each feeding trial we had to collect all the tubes we would need the next day and label them all—we needed about 100 tubes total for one feeding trial. We also needed to make sure all the feeding trial containers, filters, syringes, and everything else was washed with DI water and ready to go. If we have ICARE restoration the next day, we would prep the sponges that were being out planted by attaching them to small pieces of coral rubble.

In total, in my 53 days in the keys I completed 72 scientific dives throughout the upper and middle Florida Keys. But my summer is not over yet! After a brief break, I am headed to the Smithsonian Tropical Research Institute in Bocas Del Toro, Panama for the second half of my internship. I look forward to sharing my research adventures from Panama!