The lovable Dory (Source: http://hellogiggles.com/finding-dory-2/)

The lovable Dory (Source: http://hellogiggles.com/finding-dory-2/)

“He either said we should go to the back of the throat, or he wants a root beer float,” – a very identifiable quote for any die-hard Finding Nemo fan. This was just one of the many one-liners uttered by the chatty and forgetful Dory in the 2003 animated Disney film. People went crazy for the unsuspecting dynamic duo of the worrisome and pessimistic Marlin and his sidekick Dory as they searched the seas for Marlin’s lost son Nemo. The film raked in an astounding $936 million worldwide in 2003, making it the second highest-grossing film of that year. Coupled with the sale of movie tickets were the increases in purchases of clownfish. After theaters released the film, sales of clownfish resembling the beloved Nemo dramatically increased, rising as much as 40%, according to some estimates.

With the release of Finding Nemo‘s sequel, Finding Dory, set for June 17th of this year, the dash to stores for pet Dorys is inevitable. Along with this demand comes the ensuing strain on fragile coral reef environments. Despite Dory’s resilient and optimistic quest to rescue Nemo in the film, blue tangs raised in captivity have unfortunately been much less resistant to hardships. Next month, when Dory stars as the leading lady of her own motion picture, the difficulty with raising captive blue tangs will force collectors to harvest more blue tangs from the wild. The process of harvesting is often destructive to the reef environment as many of the sourcing practices are unregulated.

The Difficulty in Raising Blue Tangs in Captivity

Eric Cassiano observing his broodstock of blue tangs at the University of Florida's Tropical Aquaculture Lab (TAL) (Source: https://www.hakaimagazine.com/article-long/breeding-dory)

Eric Cassiano observing his broodstock of blue tangs at the University of Florida’s Tropical Aquaculture Lab (TAL) (Source: https://www.hakaimagazine.com/article-long/breeding-dory)

One of the many researchers experiencing the struggles of breeding blue tangs is Eric Cassiano, a Ph.D. student at the University of Florida, working on his Ph.D. in Fisheries and Aquatic Sciences. He currently works at the Tropical Aquaculture Laboratory (TAL) on a new project exploring the process of producing marine ornamental fish species. Cassiano knows all too well the trials and tribulations of raising blue tangs in captivity. He has been involved in the dozens of failed attempts at producing even just one blue tang out of batches of 4,000 eggs – and now, a new pressure is mounting, as the release date for Finding Dory quickly approaches. “When Finding Dory comes out, my personal opinion is that people won’t be able to buy enough [blue tangs],” Cassiano explains. “That leads down the dark path of how we are going to get more of them. And that could be a problem.”

Harvesting Blue Tangs

Each year, a mix of collectors, distributors, wholesalers, and pet stores collect an estimated 20 to 24 million ocean animals and distribute them into 2 million homes and public aquariums (according to extensive analyses done by Andrew Rhyne, a marine biologist with the New England Aquarium and Roger Williams University in Bristol, Rhode Island). Over the period of a year between 2004 and 2005, Rhyne and his colleagues tallied the import of 11 million marine creatures in the United States. In the mix of creatures were over 1,800 species of ornamental fish, as well as corals and urchins. As many as 300,000 blue tangs alone are traded globally – an estimate based on 11 years of data recorded in the United States. Rhyne adds that putting a dollar amount on the aquaculture industry is very difficult. Its retail value is estimated between $200 and $330 million – but even that number is based on 15-year old data.

The Marine Aquaculture Industry

Diagram depicting the environmental risks associated with marine aquaculture (Source: http://www.beachapedia.org/Aquaculture)

Diagram depicting the environmental risks associated with marine aquaculture (Source: http://www.beachapedia.org/Aquaculture)

Despite its booming economic success, the marine aquaculture trade industry is lacking in its environmentally friendly practices. The industry doesn’t have regulations controlling collections techniques. The Coral Triangle (the waters around Indonesia and Philippines) supplies the bulk of aquarium fish sold around the world. There are collectors in this region that still use cyanide, a poison that paralyzes the fish temporarily, allowing collectors to catch them with ease.

Breeding Blue Tangs

Raising fish in captivity would be one option to cut down on the numbers of fish harvested from the wild. Modern aquaculture has been able to successfully produce dozens of varieties of farmed fish, such as catfish and tilapia. Due to their abundant batches of large eggs, these varieties of fish are relatively simple to raise. There are even some species of ornamental fish, like the clownfish, that have been able to be raised in captivity. Unfortunately, the blue tang has not been so lucky, along with several other varieties of ornamental fish.

A blue tang in its natural habitat (Source: http://www.caribbeanpets.com/site/salt-water/hippo-blue-tang.html)

A blue tang in its natural habitat (Source: http://www.caribbeanpets.com/site/salt-water/hippo-blue-tang.html)

Turns out there are other scientists, in addition to Cassiano’s research group, that have been attempting to tackle the blue tang debacle. Back in 2000, a team at the Ocean Institute of Hawaii’s Pacific University began a harrowing journey in the attempt to breed yellow tangs. After a long five years, mature yellow tangs finally produced viable eggs that later hatched in the lab tanks. The team knocked down one roadblock in getting the eggs to hatch – but a slew of difficulties followed. What do you feed fish smaller than a chia seed? What is the best kind of environment to raise newborn fish? Other factors like tank size and water temperature were things the researchers took into consideration.

The researchers weren’t able to feed the newborn tangs the typical newborn fish nourishment, rotifers (a type of zooplankton), because their newborns’ mouths were to small to encapsulate them. The team ended up feeding the tangs copepods instead, a much smaller zooplankton. In 2010, they began breeding copepods in the lab for the tangs to consume. While fidgeting with the other factors, they determined a water temperature of 27 degrees Celsius worked well for the little tangs. Finally, after endless trials in the attempt to raise just one tang, in mid October of 2015, the group was able to rear 150 fully formed and healthy baby tangs. Now if only Cassiano and his Florida group could have the same success…

Rising Tide Conservation Initiative

Rising Tide Conservation (Source: http://www.risingtideconservation.org/)

Amongst all the struggles to raise blue and yellow tangs in captivity, the struggle of how aquariums could promote a message of conservation while harvesting the majority of their fish from the wild loomed overhead. Judy St. Leger, vice president of research and science at Sea World Parks & Entertainment in San Diego, led months of meetings with scientists, aquarium reps, and pet store executives, resulting in the establishment of the Rising Tide Conservation initiative. The mission of this organization is to further the health of coral reefs by creating new techniques for raising ornamental fish in captivity and advocating for commercial production to offer an alternative to wild harvest. Rising Tide Conservation is funded, in part, by Petco and SeaWorld. They have come up with a list of species that have the highest harvest demand, including blue and yellow tangs.

Rising Tide takes a refreshing twist on its work that most organizations wouldn’t dare do: they publish all their findings – the good and the bad. Everything Rising Tide carries out is completely transparent to the public. To this day, collaborators at Rising Tide have bread more than 20 species of tropical marine fish in captivity and three of the species are now in commercial production. According to Sandy Moore, president of Segrest Farms (one of the world’s largest ornamental fish wholesalers), “The marine [breeding] business is in its infancy, but it’s making a huge headway.”

What the Future Holds for Cassiano and His Florida Team

Back at TAL, success is far and few between. The team’s most successful batch of tangs made it 22 days, before predictably failing. As the work continues, the group fiddles with their tank conditions, hoping that one magic combination of factors will reward them a tang or two. It took the Hawaii lab a long 15 years to raise healthy yellow tangs, so researchers at TAL remain optimistic. Despite the team’s positive outlook, they can’t help but feel the least bit unsettled as Finding Dory gains millions of fans on Facebook. The release date hangs over the team like a looming storm cloud as they prey for a miracle to produce a healthy batch of little Dorys to satisfy the soon to be raging demand of the public. Fingers crossed!

Sources:

https://www.hakaimagazine.com/article-long/breeding-dory

https://en.wikipedia.org/wiki/Finding_Nemo

http://www.risingtideconservation.org/