ISLAMORADA -- Back in the 1960s, University of Miami marine scientist Walter Starck recorded 517 species of fish in and around Alligator Reef off Islamorada — the greatest number recorded from any one place in the Americas at that time.
Today, following decades of human and natural impacts, this coral ledge topped by a lighthouse and fringed with rubble and sea grass still delights scientists and divers with its rich species diversity.
Islamorada underwater photographers Carlos and Allison Estape — volunteers with the nonprofit Reef Environmental Education Foundation (REEF) — recently embarked on their own fish count at Alligator Reef, a no-take zone ever since the 1997 implementation of the Florida Keys National Marine Sanctuary management plan. The couple is up to just over 100 species on a single dive, with the photographs to prove it. Lad Akins, longtime operations director for REEF, said the Upper Keys sanctuary preservation area is among only a few other known locations in the tropical Western Atlantic with a one-dive, 100-plus fish species count. Chief among them is the tiny island of Bonaire in the southern Caribbean.
“Both are protected areas, but other than that, they’re pretty different,” Akins said.
For one thing, the Alligator Reef ledge is fairly shallow, while Bonaire lies on the edge of a steep coral wall. Both are popular scuba diving and snorkeling sites located at opposite ends of the Caribbean region.
The Estapes’ findings might be important because the marine sanctuary advisory committee is considering tweaking the management zones within the 2,800 square-nautical-mile region. The committee could recommend re-opening some areas to fishing and lobstering while closing others.
But for the Estapes themselves, the project has reignited their passion for scuba diving on their home reef.
“We track everything we see, where we saw it, the date we saw it,” Allison said. “You feel like you’re on an Easter egg hunt. You’re always looking for something you’ve never seen before. It’s super exciting to see a species you’ve never seen before.”
The couple said they would make their images available to REEF as identification aids for future volunteer fish counts. They also would like to share them with scuba shops and clubs in the Keys and southeast Florida.
“People could scroll through and find things to look for,” Allison said. “It would be great if some of the dive clubs in Miami would get into this.”
The Estapes’ enthusiasm for fish counting often spreads to their diving companions. On a recent plunge at Alligator Reef from the Islamorada Dive Center boat, the couple — together with Akins, Keri Kenning, Ed Martin and Elizabeth Underwood — scoured the region for nearly two hours to a depth of about 25 feet armed with a fish ID booklet and a waterproof pencil and checklist.
Kenning quickly got into the spirit.
“I did cartwheels when I saw a small-mouthed grunt,” she said. “I was in a school of 100 fish, and there it was.”
The party also netted several invasive lionfish from the reef before returning to the boat to tally their results.
The final count for six divers: 117 species.
Akins said counting fish is like birding — but not.
“With birding, you’re there with binoculars,” he said. “Here, you’re right up close to the fish.”