Invasive snakehead fish sighted in Burnaby's Central Park lagoon
An aggressive predatory fish has been sighted in a lagoon in Burnaby's Central Park raising concerns about the potential impact of the invasive species.
A video was posted online by someone who said they were at the park on Mother's Day to check out the carp and koi and were surprised to find a large snakehead fish instead.
"This is the first sighting report about this species of invasive fish we have had in Burnaby. It is in Central Park pond," Burnaby parks director Dave Ellenwood said by email on Wednesday. "Staff have contacted the Ministry of Environment to discuss a plan of action to deal with it. They indicate that they will be sending a team to assess the situation and remove the fish as soon as they can. They have not indicated a specific time to us when that would occur."
The snakehead fish is native to Africa and Asia where it is prized for eating, according to Wikipedia. There are actually about three dozen species of the freshwater fish, which have sharp teeth and can range in length from 10 inches to more than one metre (3.3 feet).
In B.C., they're imported live and sold for aquariums or as food. For years, they've been sold in Asian markets such as T&T Supermarkets.
"They eat mostly other fish but they can eat amphibians and a variety of other animals, and they can eat fish, for example, up to a third of their body length," said
Jonathan Moore, associate professor biology at Simon Fraser University. "They're pretty voracious so their impacts are potentially large."
They're also pretty fertile, maturing after two to three years, and producing offspring very quickly, with spawning females releasing up to 15,000 eggs as often as five times a year, far more than local fish species such as salmon or trout.
Snakeheads are also very tolerant of a variety of water conditions, including warmer or low oxygen water.
In fact, they have a primitive lung system—"they actually can gulp air"—that allows them to slither across land in search of other water bodies.
While local reports stated snakeheads can survive on land for up to an hour, Moore said he's read research that says they can stay out of water for days or weeks, something that's likely dependent on the humidity and dampness of the habitat.
The giant snakehead species grows to a length of about 1.5 metres, he said, and could potentially eat a small dog. But Moore stressed it's unknown what, if any, species is in Central Park.
"It would take a very small dog and a very big snakehead for that to be any risk. The bigger risk is the damage to the ecosystem."
Snakeheads have made headlines across the United States in recent years where authorities are struggling to remove the invasive species, including in Maryland, Florida, New York and California.
They have no natural predators in North America, so it's expected that native fish populations will eventually be decimated by the snakeheads, he said, although their exact impact is still being assessed.
"In order to get rid of them what you need to do is basically poison the whole water system and kill all the fish and then restock the native fish," Moore said, noting that's what was done in a Maryland lake but the effectiveness of this tactic is not yet known.
In March, the Maryland Department of Natural Resources announced its second annual snakehead contest in which fishermen can win prizes worth up to $200 for catching and killing the invasive fish.
"This is true for invasive species in general, once they're established, it's hard to get rid of them."
Moore noted that unlike in the U.S., which has banned the importation and sale of snakehead fish, "that's not the case in Canada."
In some parts of Asia, snakeheads are actually farmed. And he's been aware for some time that the fish is sold for food locally.
"So I've been worried that they'd pop up around here because of that. Anytime you have a fish around a lot of people usually it gets released. People are funny about that kind of thing."