After Nemo hit the big screen, sales of orange and white striped clownfish rose by as much as 40 percent, according to some estimates. Conveniently, clownfish are simple to breed in captivity, and demand was easy to satisfy. When a similar rush for pet Dorys inevitably follows the new film, fragile coral reef environments are likely to suffer. That\u2019s because even though Dory was a model of resilience and optimism in her perilous quest to rescue Nemo from a dentist\u2019s office fish tank, young blue tangs have proven much less hardy inside lab tanks. As Dory graduates from sidekick to leading lady, the lack of a captive-bred option will drive collectors to source more blue tangs from the wild\u2014a harvest that\u2019s often unregulated and destructive.<\/p>\n
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<\/a>Clownfish (or clown anemone fish) are native to tropical waters in the Pacific. Unlike blue tangs, they can be raised in captivity. Photo by Reinhard Dirscherl\/Corbis<\/p><\/div>\n
Dory was, as usual, in the back of Cassiano\u2019s mind when he arrived at work that spring day. And he was eager to check on the not-yet-fish, which were defying expectations. Two weeks earlier, 4,000 eggs had hatched into nearly invisible larvae inside a cylindrical tub big enough to fit several toddlers. And while most previous trials had ended around day six, these fishlets lived on. When the larvae surpassed another typical crunch point at 11 days, Cassiano wondered if they would finally make it. \u201cYou try not to get too excited because there\u2019s a lot of disappointment,\u201d he says. \u201cBut it was awesome.\u201d<\/p>\n
Then came the beginning of the end. Cassiano noticed that the larvae looked pinheaded, which meant they weren\u2019t eating. Some were swimming in tight little circles, also a sign of demise. On day 17, a photograph taken of one member of the batch captured a mostly translucent, two-millimeter-long body with a splotch of yellow beneath a ghostly blue eye: a fish in a state of becoming. By day 20, all were dead\u2014another setback on a long road with a now imminent deadline.<\/p>\n
\u201cWhen Finding Dory<\/em> comes out, my personal opinion is that people won\u2019t be able to buy enough [blue tangs],\u201d Cassiano says. \u201cThat leads down the dark path of how we are going to get more of them. And that could be a problem.\u201d<\/p>\n Every year, a sprawling network of collectors, distributors, wholesalers, and pet stores channel an estimated 20 to 24 million ocean animals into two million homes and public aquariums around the world, according to rigorous analyses by Andrew Rhyne, a marine biologist at the New England Aquarium and Roger Williams University in Bristol, Rhode Island. Demand is highest in the United States, where over the course of a year spanning 2004 and 2005, Rhyne and colleagues documented the import of 11 million marine creatures, including more than 1,800 species of ornamental fish, along with corals, urchins, and other creatures that create mini-ecosystems within the confines of glass tanks.<\/p>\n The annual tally includes as many as 300,000 blue tangs traded globally, Rhyne says, an estimate based on analyses of 11 years of data in the United States. Still, he adds, putting hard numbers on the full scope of the marine aquaculture trade is extremely challenging. The retail value of the global industry, for example, is often given a rough estimate of between US $200-million and $330-million spent on fish by consumers, but those estimates are based on 15-year-old data, and, really, \u201cwe have no clue,\u201d Rhyne says. \u201cIt could be worth a lot more.\u201d<\/p>\n As a whole, the industry is not renowned for its environmentally friendly business practices. The waters in the Coral Triangle, the region around Indonesia and the Philippines, supply most marine aquarium fish sold worldwide. And without regulations to control collections, this region also suffers most from damaging collection techniques. Some collectors there still use cyanide, a chemical poison that temporarily paralyzes fish and harms corals. Even in Hawai\u2018i, which also supplies aquarium fish and where protected areas offer refuge, some activists and dive operators are pushing for legislation that would ban fish collecting. That movement is fraying nerves among aquarium and hobbyist insiders. If Hawai\u2018i closes its reefs, ethically sourced tropical fish will become harder to find, putting yet more pressure on places where destructive practices persist.<\/p>\n Breeding ornamental fish in captivity would solve many of these problems, but it hasn\u2019t been so easy. Even though modern aquaculture has produced dozens of viable varieties of farmed fish\u2014including many of the catfish, trout, and tilapia that people eat\u2014most are freshwater species that produce prodigious loads of eggs and relatively large larvae that are fairly simple to raise. Some ocean ornamentals, including clownfish, are already in regular production, too. But many other marine varieties have been tougher to domesticate, particularly smaller reef species like blue tangs.<\/p>\n Cassiano\u2019s group is not the only one that has been grappling with that problem for a long time. In 2000, a team at the Oceanic Institute (OI), an affiliate of Hawai\u2018i Pacific University, began what would become a marathon effort of trying to breed yellow tangs, which define Hawai\u2018i\u2019s snorkeling reefs with streaks of electric yellow. It took five years just to coax mature yellow tangs to produce viable eggs that would hatch in lab tanks. When the translucent eggs burst open, larvae emerged alongside a vexing problem: what do you feed to newborn fish that are smaller than poppyseeds?<\/p>\n
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