Ministry: Humans brought gobies to Hillsburgh pond

It’s more than likely the round goby infestation at the Hillsburgh pond is the result of human intervention.

Art Timmerman of the Guelph office of the Ministry of Natural Resources was at Erin council on Nov. 19 to discuss the announced discovery of round gobies in the Hillsburgh pond on the West Credit River.

Timmerman said council may have heard about the recent discovery via a News release earlier in the year.

In his update to council, Timmerman provided information about how different agencies are approaching the issue.

He also hoped to garner council’s support in future actions which may have to be taken to deal with the invasive species.

“Round gobies [are] an invasive species in Ontario since 1990,” said Timmerman.

He added most people have heard about the impact and spread of zebra mussels, “but these are spreading throughout Ontario even faster.”

He said there is a lot of concern as to the impact of the round gobies, which eat the eggs of native fish species.

Timmerman said most of the gobies are limited to the Great Lakes and within the lower sections of rivers draining into the lakes.

“Usually they spread up to the first barrier.”

In the Credit River, there are gobies in the lowest section, he said. However, in August, Timmerman said representatives of Credit Valley Conservation found gobies in the Hillsburgh pond.

Gobies have been found short distances upstream and downstream of the pond. The research done, “gives us the feeling that the gobies are restricted to a fairly small area.”

He said if one viewed the entire Credit River watershed, this is a relatively small part of that area.

And, there is a large stretch of uninfected river between Hillsburgh and the downstream portion of the Credit River, which is infected.

One of the issues is that the streams and some of the ponds are on or along privately owned lands.

Therefore any efforts to control or eradicate the gobies is completely dependent on the goodwill of the landowners.

He said the ponds, which have existed for a long time, are filled with sediment and are relatively shallow - which the gobies prefer over nearby streams that generally have lower water temperatures.

As to dealing with the gobies, Timmerman said this year  the province developed a process to deal with invasive species.

Timmerman said work has been done to look at the risk to native species if the gobies are not controlled.

In the short term, work has been done to contain them, so the goby population does not spread. That gives agencies time to determine the best approach for control or eradication.

“We believe the pond is the downstream limit of the gobies at this point,” said Timmerman.

Over the long term, agencies are looking at the best means of containing, suppressing and possibly eradicating the gobies.

Timmerman pointed out most of the known information is from those in the Great Lakes. He added very little information is known on how they survive in a cold water stream habitat.

Councillor Barb Tocher asked for a “best guess on how the gobies got (in the Hillsburgh pond).”

She asked, “Did somebody dump a bait bucket?”

Timmerman said while it can never be proved, “that is what we think.”

He added the guess is based on where gobies have been found and the fact there were bait containers in the vicinity.

Timmerman noted the pond is known for its small mouth bass. He also pointed out the gobies could not have come from the lower portion of the Credit River.

“There are a number of dams ... and the Niagara Escarpment. There is no way they could have got there on their own,” he said.

One approach would be using a chemical that kills gilled species - but only after saving native species.

Using electro-fishing, desirable native species can be caught ahead of time and moved to a safe place. “But it would be a massive part of the operation.”

Councillor John Brennan asked about the overall impact of the chemical to kill the gobies. He was told the chemicals would likely affect fish species downstream until it was diluted to a concentration which is not harmful.

Mayor Lou Maieron asked if Hillsburgh was the hot spot of gobies in the Credit River watershed.

Timmerman said aside from the lower portion of the watershed, Hillsburgh is the only other location where gobies have manifested.

The concern however is that while the gobies may not be able to travel downstream, high water levels or storm flows could push them downstream into currently uninfected areas.