The Gulf of Maine Times: Vol. 7 Num. 2 : Editor's Notes Think before dumping that aquarium tank

On a visit to southern New England recently, I stopped into a large pet supply store to buy dog food. While passing by a bank of aquarium tanks, one creature in particular caught my eye. Floating solo in all its languorous glory was the beautiful and predatory Pterois volitans. With its candy-cane stripes, fan-like fins and long venomous dorsal spines, the commonly named lionfish resembles a colorful aquatic porcupine. Native to the Indo-Pacific to southern Micronesia, the fish uses these spines to spear and immobilize its prey. This probably explained why it had a tank all to itself.

"May I help you?" inquired a clerk. The tag pinned to his shirt pocket read "Aquarium specialist."

I began to tell him about how divers as far north as Long Island, New York, had spotted lionfish that likely got there after being discarded from home aquarium tanks.

Ray Roman (left) and Dan Bowers and of Uncle Ned's Fish Factory in Massachusetts tell customers "Don't just toss it anywhere..."
Photo: Butch Scribner

"Really? I didn't know lionfish could live in cold water," the clerk replied as he scuttled away to help another customer. "That's sure news to me."

It was news also to the biologists that have tracked reports of the fish up the Atlantic coast. How this tropical marvel made it to Long Island and survived remains a head-scratcher, yet the theory about the aquarium tank dumping is top on the list of suspected pathways.

According to the U.S. Geological Survey (USGS), each year, more than 2,000 non-native fish species, representing nearly 150 million exotic freshwater and marine fishes, are imported into the United States for use in the aquarium trade. And the exotic good looks of the lionfish make it one of the most popular buys. That is until the buyer gets bored or inconvenienced.

"It happens all too often," says biologist Pam Fuller of the USGS in Gainesville, Florida. "The fish tank that the budding hobbyist wanted so much becomes an unwanted responsibility and the nearest stream, or water source of any kind, provides the solution."

While the vast majority of tropical fish cannot survive the chilly waters of the North Atlantic, those that do could proliferate and become a nuisance by outcompeting native fish for food and spreading disease.

Dan Bowers, of Uncle Ned's Fish Factory in Millis, Massachusetts, hadn't heard about the Long Island lionfish, yet he assures me that any aquarium plants and fish he sells will not end up in the Gulf of Maine watershed. For one thing, Dan knows aquariums. "I've had a tank going almost 100 percent of the time I've been alive," he tells me. He and his business partners, brother Ned Bowers and Ray Roman, routinely tell customers not to discard any plants or fish into the wild.

"Unless you tell them, most people really don't think about the problems with invasive species one way or another," Bowers says. He names the Eurasian watermilfoil (Myriophyllum spicatum) to illustrate his point. These freshwater plants form dense mats of vegetation on the surface of the water crowding out important native aquatic plants needed for a healthy fishery. The plant is spread from fragments picked up by the propellers of recreational boats and can infest an entire lake within two years of introduction to the system.

"I tell people to be very careful with this stuff–don't just toss it anywhere," Bowers continues. The same goes for fish and amphibians. "I tell customers, 'do not release it back into the wild, because you never know what kind of diseases exotic fishes and reptiles from aquariums can carry.'"

Uncle Ned's Fish Factory is among dozens of aquarium stores in Massachusetts that Shannon Weigle and her team at the Massachusetts Bays Program are targeting for a state-wide public education campaign aimed to reduce the release of exotic species into marine and freshwater environments. A recent workshop sponsored by Mass Bays at the New England Aquarium brought together experts from environmental agencies, the pet trade and pet shop owners to discuss concerns about invasive species and actions needed to prevent their spread. Mass Bays is also gathering information from store owners on species traded that could become a problem if released.

"Part of the problem is that scientific names are rarely used," Weigle says. "One particular organism might have a couple of common names. So we have to figure out exactly what is being moved around."

Besides watermilfoil, other freshwater invasive plants linked to the pet trade include fanwort (Cabomba caroliniana) and Hydrilla verticillata, both of which have cost states millions of dollars in eradication programs.

When it comes to invasives in marine waters, Weigle says, nothing beats Caulerpa taxiflora, also known as the killer algae.

Caulerpa is a classic example of an alien that just takes over. Nothing eats it and nothing competes with it. The weed, originally from the Caribbean, was imported to Europe and used as decoration for tropical fish tanks. It was released from an aquarium in Monaco and a patch about one yard square was seen nearby in 1984. It now covers thousands of acres of Mediterranean sea floor where it has literally choked the region's fishery to death. While not toxic to human beings, Caulerpa releases chemicals that can harm marine animals and it smothers the sea floor wiping out native species of seaweed, thus, turning the food chain upside down.

Australia has its own Caulerpa headaches, likely caused by aquarium owners, and more recently Southern California. The discovery of the species near a San Diego harbor in 2000 was found to be genetically identical to the strain in the Mediterranean. Once again, scientists suspect the release took place after someone emptied a fish tank into a storm drain.

Could Caulerpa take hold in the Gulf of Maine? "The general thought is that it can spread up to Long Island, but that it would have a difficult time flourishing beyond," Weigle says. "Yet it's such a rapidly growing and highly adaptable species that some scientists are saying it could adapt to cold water climates. It's listed as a species of concern for Massachusetts, so we're afraid it might adapt up here."

Caulerpa is banned from sale in the United States, but remains sequestered inside countless aquarium tanks. That thought alone should make any aquarium store owner very nervous, says Bowers of Uncle Ned's.

"My biggest concern is if these aquarium releases continue to happen and cause invasive species problems they're going to start regulating us," he says. "Right now, they hardly regulate us at all. So the more careful people are, the less need for regulation. I'm all for that."