08/16/2014 12:01 EDT | Updated 10/15/2014 05:59 EDT

Goldfish dumped by Coquitlam pet owners become invasive species

They're easy to take care of, inexpensive and entertaining, but goldfish and other aquatic pets including exotic fish, turtles, bass and carp are getting into local waterways and breeding and competing with our own native species.

And In Coquitlam so many goldfish are winding up in Como Lake, the city is cracking down with hefty fines ranging from $2,500 to $250,000

David Scott with SFU's School of Resource and Environmental Management says there's good cause for concern.

"If you have non-native species that become established in let's say the Fraser River, they would be competing and influencing dozens of local species that we have here including salmon which are economically important," he said.

In 2012, the infamous snakehead fish eluded conservation officers for weeks. Scott was one of the SFU researchers who studied it.

He says people may think they're freeing a captive pet by throwing it into a local pond, but warns the act can have bigger implications than most people realize.

So what do you do, if you don't want your pet fish or turtle anymore?  Many pet stores say they'll take them back.