The report in the local media last week of a sighting of a snakehead fish in the lagoon in Burnaby’s Central Park is cause for some spine-chilling thoughts. Currently, the B.C. Ministry of Environment biologists are investigating but the mere idea of someone releasing such a menacing fish into the water is horrifying.
With over 30 species, snakeheads are a predatory fish indigenous to southeast Asia and parts of Africa. They are tan and blotchy brown and can grow over a metre long. Their mouths, cluttered with sharp teeth not unlike pike or walleye, reach well behind the eyes earning them their reputation as top-level predators with a skill to kill. They will lurk in shallow waters feeding on fish, crustaceans, plants, and insects. With a primitive lung system, they can breathe air and have the ability to navigate on land for several days, wiggling snake-like to a new water source if their original one dries out. One species can survive in cold water making Canada’s freshwater systems ideal habitat. It could cause havoc for aquatic ecosystems and recreational fishing.
Northern snakehead, native to China, Russia and Korea, were imported to the U.S. for aquarists and for sale as a food or medicinal fish to the Asian community. But irresponsible owners released unwanted fish into local ponds. Infestations have occurred in New York State, Maryland, Florida, Maine, Massachusetts, California and Hawaii. In Maryland, officials tried to eradicate them by poisoning infested ponds but they have since surfaced in the Potomac River making their control vastly more complicated. When a snakehead showed up on a fishing line in Ontario in 2010, the province promptly banned the sale of all live snakeheads. Now the Lower Mainland is facing the dilemma.
“A couple of people have seen it,” said Matthias Herborg, aquatic invasive species specialist with the B.C. Ministry of Environment. “But they’re unconfirmed reports.”
This week, officials from the City of Burnaby and the ministries of environment and forestry will use nets and look at the lagoon and nearby ponds to see what they can find, then decide on a course of action.
“The most common means of snakehead introduction is through their availability in some food markets and pet stores,” said Dr. Michael Russello, associate professor with the Department of Biology, UBC, Okanagan campus. “It is still legal in B.C. to sell live snakehead fish. The likelihood of more than one individual being introduced is dependent upon the mode of introduction, so it is really hard to say. Even the introduction of one gravid female could be devastating, as they can produce up to 150,000 eggs.”
Pond management if a snakehead is suspected will be essential and really challenging especially if a self-sustaining breeding population is discovered which, Russello said, would make options for eradication quite limited. And successful eradication would depend on the number of individual fish that have been introduced.
“The number one precaution that the public can make is not to release any non-native species into the environment,” stressed Russello. “Invasive species are the second greatest threat to biodiversity (habitat destruction is the first). The best strategy to prevent such impacts is to avoid intentional or unintentional introduction in the first place. (Given that) selling live snakeheads is now prohibited by law in Ontario, I would think it prudent for B.C. to follow suit given the latest scare.”
“We have to look at specifics,” said Herborg. “Once we know if the fish is there we will do some other techniques.”
Like Russello, Herborg stressed the importance that the public not release aquarium fish into local waters. “It’s a huge risk and very hard to know what the consequences are.”