As we gear up for the release of Finding Dory, concern is mounting regarding how the film might effect “Little Blue’s” species, the Pacific blue tang.
It’s the same story we’ve seen play out before: family goes to the cinema, children (and let’s be honest, adults) get excited about their favorite characters, and someone inevitably rushes out to buy their very own incarnation. The trend emerged in full swing after the release of Nemo, when sales of clownfish hit an all time high. It resurfaced in 2014 after the TMNT reboot, when thousands of pet turtles ended up abandoned, and again this year after Zootopia left a huge demand for rare, protected fennec foxes in its wake. For the little-studied blue tang, a staple in many of the world’s coral reefs, a pet-trade boom like this could have catastrophic results.
So, fellow nerdlings, help us spread the word! Shout it from the highest peaks of Mount Wanna-Hock-A-Loogie: after you see the film, do not find Dory.
P. Sherman. 42 Wallaby Way, Sydney
The Saving Nemo Conservation Fund in Australia, which protects and breeds clown fish, estimates that some 400,000 blue tang are collected each year from the ocean for pets. And because they’re near-impossible to breed in captivity, this is the only way we have to supply the pet trade. This harrowing reality has the world’s top aquarists scrambling for a solution, and while we’re making progress, we’re just not there yet.
As Emily Sohn points out in this wonderful piece for Hakai Magazine, tang emerge from their eggs smaller than poppyseeds, and that makes raising the tiny fish particularly challenging. Not to mention that their growth stages are triggered by environmental factors like current changes, smells, and other chemical cues that are difficult to recreate in a nursery tank.
“The broodstock (mom and dads) also need large tanks to encourage spawning,” adds Judy St. Leger, president of Rising Tide Conservation, an organization dedicated to developing alternatives to wild capture of reef fishes. “The diets fed to the parent fish are very important in producing good quality eggs. Once those larvae arrive, they are tiny – microscopic. We can’t just give them a pinch of flake food.”
Because typical fish feeds are too large for the miniature mouths to handle, St Leger and her team must grow sensitive plankton as well. After five years of work on blue tang, they have yet to fully crack the code. “We can very successfully raise the larvae to about 16-17 days of age,” she says. “But we need them to get to 50-60 days.”
It’s a struggle shared by many, including University of Florida biologist Eric Casino. “When Finding Dory comes out, my personal opinion is that people won’t be able to buy enough [blue tangs],” he told Hakai. “That leads down the dark path of how we are going to get more of them. And that could be a problem.”
Let’s Name the Zones
Though Nemo and Dory met in the open ocean, tangs like Dory are typically found on or near coral reefs. As juveniles they feed largely on tiny crustaceans and other zooplankton, but as they grow, the fish turn to an entirely green diet. That makes them of particular importance to reef ecosystems.
The electric blue vegetarians eat encrusting algae that, left untended, can grow over coral, starving it of light. Many corals rely on a different kind of algae, symbionts known as zooxanthellae, that live within their tissues, for food. It’s a fair deal: zooxanthellae get free protection and housing within the coral polyps, and in exchange use the power of photosynthesis to provide their landlords with precious sugar. Without enough light, the algae squatters will die or move on, a process that causes coral dieoffs and bleaching. Should demand for tangs skyrocket after Finding Dory hits theaters, we may see a top-down effect on reef ecosystems over time.
But surely there are rules … right? If there’s one thing that’s proved tried and true in these situations, it’s that catch limits aren’t enough to stop poachers from fueling the pet trade. About 1,800 tropical fish species are involved in the recreational aquarium market, and that makes illegal activity hard to pin down. The industry itself lacks a central governing body to enforce regulations on a wide scale, and the Indopacific —a blue tang stronghold which accounts for around 80 percent of the fish imported into the United States — holds some of the known poorly managed fisheries.
Beyond concern for tangs in the wild, there’s another reason you should refrain from buying one: they make pretty awful pets. For starters, these fish are venomous.
Blue tangs are members of the surgeonfish family, a group known to possess special barbs known as “caudal spines” which can deliver a mild venom. The spines are located on either side of the caudal peduncle, the region where tail meets body (we like to call this the “pedunkadunk”). When the fish is under stress, it will violently thrash the tail in a side-to-side motion, inflicting deep wounds that are perfect for transferring venom, and highly prone to infection. While this defense strategy is meant for would-be predators, human handlers are certainly not immune to its wrath.
While not deadly, the blue tang’s “sting” is potent enough to cause extreme swelling (one report suggests an aquarist’s hand reached cantaloupe size before he set off for the ER), discoloration, and a burning sensation that lasts 7-10 hours, and is followed by a dull ache that can linger for days.
I shall call him “Squishy,” and he shall be mine, and he shall be my “Squishy.”
Say Goodbye to the Benjamins, and Hello to Your Decades-Long Friend
There’s a lot we don’t know about these reef fish, but one thing is for certain: owning one is a serious commitment. In captivity, these animals regularly live five to ten years. And while Dory is endearingly referred to as “Little Blue,” her species doesn’t stay little for long. With a maximum size of 12 inches (31 cm), well, you’re going to need a bigger boat if you’re going to keep one. Aquarists estimate that a tank suitable for keeping blue tang (180 gallons or more) will set you back between $1,000-3,000 – for the base tank setup alone. Factor in filtration systems, food, and a reef for your fish to forage in, and you’re looking at one expensive venture. A fish, people. We’re talking about a fish. You don’t need one that bad.
What to Do Instead
There are a number of environmentally friendly ways you and your posse can enjoy Dory in action. The first, of course, is visit blue tangs in a licensed aquarium. This way you know your fish friends are both sustainably collected, and well taken care of. Aquariums not your thing? Touch the butt! Go see Dory in the wild by enjoying a day on the water snorkeling or diving a reef. You can even volunteer your time as a coral health diver. Got that landlocked blues? No problem! Help blue tang and other reef fish by donating to coral restoration projects like the University Of Miami’s Rescue a Reef, or reef fish breeding initiatives like Rising Tide. (That is, if the sea monkeys don’t have your money.)
And if you’re absolutely adamant on adding to your underwater menagerie, capture the spirit of Dory with a less problematic (and easier to care for) species like the yellowtail damselfish, Boesemani rainbow, or blue betta.
“These fish are well-adapted to the tank environment, they don’t grow too big, and they are beautiful,” adds St. Leger. “Having a happy and healthy fish will teach kids to respect fish and think about the reef environment. Movies want happy endings, fish want happy beginnings.”