Scientists are turning to techniques used to raise fish sold in markets and restaurants.
Nearly one-fourth of the 36 seahorse species assessed by the International Union for Conservation of Nature are threatened with extinction. Illustrates SEAHORSES (category a) by Juliet Eilperin (c) 2012, The Washington Post. Moved Monday April 16, 2012. (MUST CREDIT: Michelle Fisher/Mote Marine Laboratory).
Shawn Garner watches over 18 tanks of hundreds of tiny seahorses bobbing among the artificial sea grasses and plastic zip ties provided to give their tails a hitching post.
"It's the coolest animal in the world," he said. "It has a head like a horse, a tail like a monkey and a pouch like a kangaroo."
Garner, supervisor of the Mote Marine Laboratory's seahorse conservation lab, is one of several experts trying to raise marine ornamental fish and other wild species in captivity. These researchers are engaging in the kinds of farming operations once reserved for fish sold in markets and restaurants.
For seahorses, the stakes are high. Nearly one-fourth of the 36 seahorse species assessed by the International Union for Conservation of Nature are threatened with extinction.
Three factors account for the deaths of tens of millions of seahorses each year: the Chinese medicinal trade, accidental catch by shrimp trawling and other fishing operations, and habitat destruction.
'They do flirt a lot'
"Being able to breed and raise seahorses is one part of the solution," said Heather Koldewey, head of global conservation programs for the Zoological Society of London, adding that fishing restrictions and other coastal protections are also essential.
Before the 1990s, seahorse farming was plagued by problems. Seahorses live in low densities in the wild -- in many parts of the world, including the western Atlantic from Canada to South America and in Southeast Asia -- so crowding them into a tank can stress them and lead to disease. Researchers in several countries, primarily Britain, the United States and Australia, have made strides in the past couple of decades, though reproducing the animals remains challenging.
The staff at the Birch Aquarium at the Scripps Institution of Oceanography in La Jolla, Calif., which has raised 12 seahorse species, found that a tank usually used for jellyfish worked better than rectangular ones. The tank contains a slice of cylinder sandwiched between the two sides, and the baby seahorses were inside the cylinder, which kept them from getting trapped at the top edges because of poor water circulation.
"That really changed things for us," said the aquarium's co-curator Leslee Matsushige.
It probably doesn't help captive breeders that seahorses -- already unusual because the males carry the young and give birth -- aren't promiscuous and instead live in bonded pairs.
"They do flirt a lot, but they're actually faithful," said Koldewey, who also serves as field conservation manager for Project Seahorse. "There's a lot of behavior to suggest otherwise, but if you do the genetic analysis, it's just all show."
Aquarists have also made some breakthroughs with sea dragons, which are related but differ in several aspects, including the way they move and use their tail. There are just two species -- leafy and weedy, named for their form of camouflage -- and they live in the temperate waters off Australia. The Aquarium of the Pacific in Long Beach, Calif., became the world's first aquarium to breed weedy sea dragons in 2001, from a progenitor named "Big Daddy," but it only repeated that feat once, in 2003.
'We're prepared' for long haul
Perry Hampton, vice president of husbandry, said that they've mimicked the sea dragons' natural environment though water temperature and light exposure but that they can't force the animals to mate.
Scripps professor Greg Rouse recently received a $300,000 grant to launch the first-of-its-kind sea dragon breeding pilot program with the Birch Aquarium.
For the most part, aquariums -- including Mote, Birch and the Monterey Bay Aquarium -- raise seahorses to populate exhibits and raise awareness of their predicament. Some innovators hope to either sell marine species to offer an alternative to wild-caught ones or reintroduce them to the wild.
Judy St. Leger, who serves as SeaWorld's director of pathology and research, said many commercial operators stopped researching once they mastered the art of raising clownfish and other popular species. She and her collaborators, by contrast, "realize that this is not a problem that can be resolved in one or two years. We're prepared to be working on it for 10 or 20 years. ... We're prepared to keep going in order to make a difference for the reefs."