Early on in Pixar’s Finding Nemo, the titular clownfish is taken from his home on the Great Barrier Reef, tossed into a plastic bag, and plopped into a fish tank. While the plucky young fish and his friends eventually make their escape, many real-life clownfish aren't so lucky. And the movie’s success worsened their situation, making exotic fish even more popular as pets. Now, some conservationists worry that the upcoming sequel, Finding Dory, will put new pressures on exotic fish populations.

"I think it was a big surprise, because the message from the film was a very good one about conservation," Karen Burke da Silva, associate professor in biodiversity and conservation at South Australia’s Flinders University, tells Travis Andrews for the Washington Post. "It was about not taking Nemo out of the sea, but the opposite happened."

The problem with keeping exotic fish such as clownfish (the group to which Nemo and his father, Marlin, belong) and blue tangs (like the forgetful Dory) as pets is that they aren’t as easy to care for as a goldfish. The fish have specific diets that can’t be replaced by regular fish food, and their underwater lives are completely different than many Pixar fans might think.

“What most people don’t realize is that about 90% of marine fish found in aquarium shops come from the wild,” Carmen da Silva, a project coordinator with the Saving Nemo Conservation Fund tells Ben Child for The Guardian. “Reef fish populations are already struggling due to warmer sea temperatures and ocean acidification caused by global warming. The last thing they need is to be plucked off reefs.”

In 2012 alone about 400,000 clownfish were imported into the United States, making it America’s fifth-most imported species that year, according to the Australian Broadcasting Corporation (ABC). Now, conservationists are afraid the sequel might spur another rush on exotic fish being sought out as pets, further pressuring animals already struggling to survive in a fragile ecosystem.

“They sometimes use cyanide poisoning to collect fish,” Burke da Silva tells the ABC. “It is used as a kind of anesthetic to knock them out so they can be easily collected in a short amount of time.”

While the demand for pet clownfish puts pressure on wild fish populations, that has eased off somewhat as exotic fish sellers began breeding clownfish. However, Burke da Silva says this isn’t be the case with the blue tang, which cannot breed in captivity, the ABC reports.

“This is because the blue tang fish release their eggs and sperm into the sea and this cannot be mimicked in a lab,” Burke da Silva tells the ABC.

For now, conservationists are bracing for a surge in popularity for exotic fish. However, they are hopeful that by getting out the word about the problems that come with keeping exotic fish for pets, audiences will walk away from Finding Dory with the right message this time.