coral reefs in Ko Lipe, Thailand

Photo: Milos Prelevic/Unsplash

The Inertia

From warming water to sunscreen to construction, there are a myriad of threats to coral reefs. However, the coral reef at ‘Anini Beach on the North Shore of Kaua‘i faces a unique danger in the form of foreign coral species that appear to have been “planted” by a well-meaning, but misguided, human.

The foreign coral was first discovered in 2021 by Robin Mazor and Tom Woods, members of Reef Guardians, an ocean conservation nonprofit based on Kaua‘i. While snorkeling, the pair noticed corals that were unfamiliar to them and showed signs of having been placed on the reef. They photographed the specimens and informed the Division of Aquatic Resources (DAR), who confirmed that the corals were not native to Hawaii, as reported in a DAR blog post. When the DAR Aquatic Invasive Species (AIS) team came to remove the colonies from the reef, they found that some of the corals had been attached with zip ties, while others had coral “plugs” that are commonly used to grow coral.

All of the foreign species that were found are commonly used in saltwater aquariums – leading the experts to believe that they were placed there by a Kaua’i resident who was dismantling a fish tank. It’s possible that the citizen had been well-meaning and thought bringing the coral back to the wild would benefit the existing reef. However, as none of the species were native to Hawaii, but rather the Indo-Pacific, they can cause a myriad of problems for the local ecosystem.

“If you implant non-native coral into this environment, if they are really resilient species, they can outcompete the native species, which would be problematic because they don’t have natural predators here … We don’t have fish that necessarily want to eat this particular species of coral,” Heather Yitalo-Ward, DAR’s Kaua‘i district biologist, told Kaua’i now.

“The other possibility is the introduction of disease. We don’t know where these corals came from. We don’t know how well they were taken care of. If they’re introduced into the wild and they have any sort of disease, they could spread that to the native population,” continued Yitalo-Ward, who claimed the non-native coral is in the general vicinity of the ‘Anini Beach boat ramp. “They could have parasites, viruses. Anytime you have introduction of coral species into this native environment, there’s mostly negative consequences. I can’t think of a positive.”

Though the original artificially implanted coral was found and removed, the issue has been far from resolved. Since 2021, Reef Guardians has repeatedly found non-native coral off ‘Anini Beach – six times total. The DAR believes that these are still remnants of the original outplanting, in which pieces of coral may have been accidentally distributed across a wide area and led to later growths.

“If you have an aquarium and need to dispose of your fish or other aquatic life, please do not release them in the ocean or streams,” wrote the DAR. “Even if you have native animals in your aquarium, you could introduce disease into the environment. The proper way to dispose of legal aquatic life is to either humanely euthanize them or reach out to other aquarium owners or pet stores who may be happy to take your animals. The Hawaii Department of Agriculture has an amnesty program that allows anyone to turn in illegal animals without penalty.”


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