Before Kimberly’s Reef was deployed in the spring and summer of 2022, the area seven and a half miles due west of Bonita Beach and 30 feet below the surface was considered a marine desert, void of fish life beyond what was living in the sand and muck. Months later it’s a very different environment, according to Kenzie Pruitt, a lab technician with The FGCU Water School.
"When I first dove the reef pre-deployment, there was nothing there. All we saw was, like, scallops and shell hash," she recalled. "Remembering those first dives to what it is now is kind of crazy that humans created this beautiful ecosystem. "
FGCU fish ecologist Dr. David Stormer agreed, "It appears that the reef is doing its job even just a few months into its existence."
The job of an artificial reef is to attract fish, which in turn attracts humans for recreational and commercial purposes. The scientists and students at FGCUs Water School have been studying how a marine desert can turn into a diverse fish habitat through this new artificial reef. It starts with an activity in the food web called succession.
"Succession is basically the process of different species of fish or even invertebrates beginning to live on the reef, recruiting to the reef and then making it their home," said Pruitt. " Then reproducing there, and slowly growing the ecosystem there."
Organisms in an ecosystem's food web are grouped into categories called trophic levels, which excites Stormer.
"We're already seeing the lowest forage fishes, if you will, the lowest level of the trophic structure of the food web, like sardines and grunt species are already appearing on the reef."
He added that they're also seeing species that are of recreational importance.
"Those include snapper species. A couple of grouper species have appeared on the reef, as well as cobia and sheepshead. And we're seeing some of the top-level predators like like sharks and turtles and maybe even some marine mammals."
Part of the research into the succession of the reef is simply counting the fish.
"The critical first step is to identify the fish species that are there and then sort of track the colonization of those individuals and species and populations over time," said Stormer.
Two metrics are involved in counting fish: the “richness” of the species and the "relative abundance." Stormer described species richness as the total number of species that appear in an ecosystem. Relative abundance is an estimate of the number of individuals per species.
"So though richness and abundance, we can start to get an idea of the biodiversity that exists on the reef," said Stormer.
Kenzie Pruitt graduated with a degree in Marine Science from Florida Gulf Coast University in December 2023. As a lab tech, she’s been tasked with creating a field guide to help others identify the various species on the reef. It's a project she hopes to continue as part of her graduate studies with FGCU next fall. In the meantime, she's busy counting the fish both in and out of the water.
"The main component I'm working on is conducting fish surveys, as well as filming those surveys, and then later analyzing the footage to determine different metrics of the the data we're collecting," said Pruitt.
For the underwater fish surveys, she uses SCUBA in order to hang out on each village of Kimberly's Reef for a longer period of time under water. She uses a water-proof slate pencil to count the fish on each village. And because fish are moving targets, she has to use broad counting measures to capture the richness and the abundance of the various species. On her slate, she will write about fish numbers as "no", "few", "many," or "abundant," which indicates over one hundred individual fish.
A second diver videotapes each culvert grouping. They take their video and slates back to the labs at The Water School.
"Then it's my lovely job to go through all of the footage and assess where I think the most fish in one frame (of video) would be. Stop it there, count those fish and then do that for all the species that I can find," said Pruitt.
Because Pruitt has dived Kimberly’s Reef since its deployment, she has seen the success of the succession, so far.
"When I first started analyzing the video footage, I basically only saw spade fish and a few grunts, but nothing like what we've seen now. So, it went from having no fish to having like 12 to 15 fish species at each culvert. It's exciting because it kind of it proves the possibility of what this reef can become."
There is an added bonus for Pruitt. "They're just really cool to look at."
A baseline fish count is important for Stormer because researchers can assess over time how sea life on the reef is affected by external factors.
"We can examine the response to both human related and natural disturbances - anything from these heavy discharges that come out of the Caloosahatchee River, harmful algal blooms or macro algal blooms, and their effect on on reef systems, but also natural disturbances like extreme weather events like hurricanes, and also seasonal changes in currents and hydrodynamic flows.
"So it's really exciting as we move forward with this project."
Major support for the production of the Kimberly's Reef documentary and dispatches is provided by Bodil and George Gellman, who believe the human spirit is behind every scientific discovery. WGCU is your trusted source for news and information in Southwest Florida. We are a nonprofit public service, and your support is more critical than ever. Keep public media strong and donate now. Thank you.