Call it the pot of gold at the end of the rainbow.
Hawaii researchers have long struggled to raise yellow tang in captivity, an effort that could one day make obsolete the practice of collecting wild fish from West Hawaii reefs. Research at Hawaii Pacific University stretching back to 2001 started out with tanks full of tens of thousands of eggs. But very few fish surviving past 50 days as scientists tried to figure out the needed balances of food, water and other factors.
This past week, scientists at HPU said they’ve become the first to achieve tangible success in captive breeding of the fish in a series of tanks. Chad Callan, director of the Finfish Program at HPU’s Oceanic Institute, announced that his team has finally succeeding in raising a cohort of yellow tang past the larval stage.
“While this is now shown to be technically possible, we still have a lot of work ahead to make this commercially feasible,” Callan said. “The important thing is that, with continued support, we believe it is possible to achieve this.”
During a calling for a 180-day ban on aquarium fishing last week to help bleached reefs recover, the Hawaii Office of Environmental Quality floated the possibility that advances in captive-raised aquarium fish could bring new sustainability to the aquarium trade.
In a letter to Department of Land and Natural Resources Chairwoman Suzanne Case, OEQC director Jessica Wooley wrote: “These new business opportunities can replace the practice of taking wild animals out of the wild to send them to far away confined aquarium tanks in a process where only some survive, similar to many aquaculture ventures that are humane to the fish as well as helpful, not harmful, to our fragile ecosystems.”
Those with aquariums seem to have an insatiable appetite for the bright lemon-colored fish. The yellow tang make up 84 percent of the aquarium harvest in West Hawaii, and 70 percent of the aquarium fish collected in the state were born on the Big Island’s leeward reefs.
While they’ve had some success with other species, researchers have struggled for years to culture yellow tang in farms. At North Kona’s Pacific Planktonics, owned by Syd Kraul, much of the challenge has been figuring out how to get the proper balance of food and water during the early stages just after the fish hatch.
Kraul began trying to rear yellow tang in 1998, but has had trouble obtaining and keeping broodstock as a source of eggs. The other big challenge has been getting the larvae to eat feed before their yolks run out.
This week, Kraul lauded OI’s success but noted, “It might take quite a while to be able to raise enough of them to make a profit.”
Now that OI has reached a benchmark, Kraul said he’ll likely move on to culturing other fish that haven’t been successfully raised before. He is currently developing flame angels and multicolored angels.
While sporadic claims of success in raising tang have popped up at various points on the globe over the years, they have lacked credible documentation, according to Reef to Rainforest Media.
