Coral World held its first seahorse release on Dec. 19 with the assistance of the Reef Rangers, V.I. Ecotours and several volunteers.
Bred in captivity, more than 140 seahorse juveniles were released into the Mangrove Lagoon in an effort to boost natural populations and increase the chances of snorkelers to see one of these amazing fish.
"By raising the young until they were one to two months in age, we are effectively reducing the numbers of predatory fish that are still able to swallow these seahorses," Dr. Donna Nemeth, Coral World's curator, said.
The young were 1 to 1.5 inches long, having grown quite a bit from their ¼-inch size at birth. At this larger size, the seahorses are also able to feed on a greater range of food items—smaller seahorses might have trouble finding enough tiny prey.
In nature, seahorses feed on small crustaceans such as shrimp, copepods, amphipods, and also tiny fish.
When the seahorses were released, each was carefully guided to a clump of algae or seagrass and allowed to wrap its tail around the plant. During that morning, snorkelers returned several times to each site where seahorses were released and observed that the seahorses were able to hang on in the gentle current and noted what predators were hanging around.
Several seahorses were snapped up by juvenile schoolmasters (a type of snapper), but Coral World personnel also observed two schoolmasters approach a seahorse, bump it gently with their snouts, and then leave. Seahorses have a rigid, bony body covering that makes them hard for some fish to eat.
Returning a week later, Donna was unable to locate any of the Coral World seahorses.
"I see three possible explanations," she said. "First, these seahorses are extremely hard to see, even in an aquarium. They are capable of rapid color and skin texture changes to blend into the background, and the algae cover is so dense there that unless you're looking straight at them (and even when you are!) they are difficult to locate.
"Second, the current in the channel near False Entrance is likely to carry the seahorses deeper into the channel and away from where the V.I. Ecotours leads their snorkel tours. So our hopes that visitors would help us to monitor the seahorse population might have been unrealistic if they are being carried away from the snorkeling area.
"Finally, some certainly would have been eaten by the diverse fish and crab population in the Mangrove Lagoon. In the wild, often fewer than 1 percent of baby fish survive to adulthood. We try to give these seahorses a 'headstart' at Coral World, but they are being released into a wild area."
The male and female seahorses are faithful to one another, reaffirming their pair bond each morning with a special greeting.
The mated pair of seahorses at Coral World has given birth to 958 babies in the past three months, in six "litters."
Behind the scenes at Coral World, Donna and her crew have about 500 babies that they are preparing for the next release.
For the first three weeks of life, each baby seahorse consumes thousands of newly hatched brine shrimp every day. As they get older, their diet is supplemented with live mysid shrimp collected near shore.
Coral World hopes to improve the odds for finding the best seahorse habitat by selecting several sites in St. Thomas and St. John for release in late February or early March.
To celebrate the success of the seahorse pair, Coral World will offer a special evening to the public from 6 to 8:30 p.m. Feb. 12. Wine, cheese and a symphony composed in honor of these mystical creatures will accompany a lecture given by curator Donna Nemeth on the fascinating life story of the seahorse and the dangers they face worldwide from overharvesting.
Following the lecture, everyone will move into the Marine Gardens exhibit to visit the seahorses on display and for a guided "behind-the-scenes" tour of the seahorse rearing facility and to view the seahorse babies of different ages.
The cost of the evening event will be $20 ($17 for Coral World members). Reservations are essential. Call 775-1555 for information.
