A Mission to Save Florida's Coral Reefs


A Mission to Save Florida's Coral Reefs

An annual mid-summer tradition early in our marriage was for my wife and I to drive to the Florida Keys for the recreational lobster season. We would hunt the delicious “bugs,” explore the awe-inspiring coral reefs, and later enjoy the evening breeze and perhaps an adult beverage.

I thought of those wonderful days when I learned a contingent of marine scientists from The Florida Aquarium and other research institutions were heading to the Keys in late July, near the traditional dates of the mini lobster season. However, their trip is not about good times. Instead of collecting lobster, more than 20 scientists will be diving at night to collect coral “spawn” and then work in labs throughout the day to preserve coral larvae.Their goal is simple and daunting: save Florida’s imperiled coral reefs, which have deteriorated terribly in the decades since I first dove them. 

Consider a chilling fact provided by the Coral Restoration Foundation: The Florida Reef Tract, which runs from north of Miami to Key West, now contains only three percent of the “once dominant staghorn and elkhorn cover that it had in the 1970s.” Other types of corals also are disappearing. For instance, 98 percent of the reef tract’s pillar coral is gone. Pollution, development, disease, dredging, boat damage and climate change are key culprits. 

The Florida Aquarium is committed to confronting this ecological catastrophe. Indeed, its Center for Conservation, being developed near Apollo Beach, includes greenhouse-like “arks,” where healthy corals can be grown. Two arks already are in operation, and six more are planned. All the funding is provided by revenue from Aquarium ticket sales and generous donations.Coral reefs are vital to Florida’s environment and economy. The reefs provide habitat for at least 25 percent of marine life. A recent study found Florida’s Southeast reefs have a value of $8.5 billion and generate more than 70,000 jobs. Part of the Aquarium’s comprehensive coral-rescue effort includes annually sending researchers to collect coral spawn in the Keys. Participants this year are: Scott Graves, the Center for Conservation director; Keri O’ Neil, coral nursery manager; and Rachel Serafin, coral biologist.

Timing is critical.  As Serafin explained, coral “usually spawn a few days after the full moon in August.”

But when there is a late July moon, as there is this year, the spawn may be split; so, the researchers must be on hand for both potential spawns. The stakes are high, and the work is draining. The team will collect spawn from the Coral Restoration Foundation coral “nursery” in Tavernier. The Foundation has seven such nurseries off the Keys.Fragments of coral are hung by fishing line from “trees” made of PVC pipes. Serafin said because the coral hangs in free flowing – and clean – water, “it can get 360 degrees of light and food,” and grows faster than it would if connected to a reef. When the fragments grow large enough, the Foundation attaches them to a natural reef. The group has “outplanted” more than 66,000 corals to Florida reefs.But given the desperate situation, this innovative effort to augment reefs isn’t enough by itself. (PHOTO: Joseph Henry).

Collecting spawn from the fragments, which can still reproduce, allows scientists to increase larvae production. Some is released into the wild, to aid natural corals whose reproduction success has plummeted. However, larvae also are brought to the Aquarium to grow in its lab. The ultimate goal is to bolster the coral gene pool and develop robust genotypes that are resistant to heat, disease and other threats. Serafin said the focus is staghorn coral, which can grow more than eight inches a year. That is remarkably fast by most corals’ plodding standards and makes it a good candidate for replenishing reefs.


In 2014, the Aquarium became the first institution to sexually reproduce staghorn in a lab. Serafin described the intricacies of the staghorn’s natural cycle: “Staghorns are simultaneous hermaphrodites. Each colony produces sperm and eggs, which are released in bundles that float to the surface. The bundle deteriorates, and the sperm and egg float freely in the water column.” Serafin said, a staghorn sperm will not “fertilize an egg with the same genetic makeup.”

When a sperm does encounter and fertilize an appropriate egg, it develops into “larvae that swims around and, if fortunate, finds a clean spot to attach itself to a reef.”The larvae’s challenge has become even more difficult because algae is smothering many reefs, the result of a mysterious disease killing the long-spined sea urchin, an algae eater. The collection team divers put nets over the coral trees. At the top of the nets are tubes that catch the bundles when they ascend. They are brought to the dive boat and then to the Keys Marine Laboratory, where they are kept in the right water conditions for larvae to form and survive.

“Separation and fertilization actually may start on board the boat,” Serafin explained. “The development of a swimming larvae may take three days.”The larvae are put in 1.5-liter bottles for the trip to the Center for Conservation. They are then put in a habitat where square tiles have been placed on the bottom. Some of the larvae will attach themselves to the tiles and grow as if on a reef. Serafin emphasized that each “individual larvae is an individual genotype.” So, this exercise can significantly bolster the coral’s genetic pool, improving the chances for a reef recovery. 


Last year, the spawn collection was able to produce 121 genotypes, a significant addition, given that it was estimated less than 250 staghorn genotypes had existed in the Florida Reef Tract. The team will spend about 10 days in the Keys, with individuals working night and dayWhen the Aquarium crew returns, Serafin said there will be months more of “microscope work monitoring the larvae.” (PHOTO: Joseph Henry.)

This Keys expedition may not be as much fun as our lobster-hunting ventures. It is, however, far more consequential. And, when the weary participants return, they will have the satisfaction of knowing they’ve played a critical role in aiding a natural wonder we cannot afford to lose.

Story by Joe Guidry, former opinion editor, The Tampa Tribune


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