Multiple factors suspected after hundreds of dead fish found in P.E.I. river

Questions swirl about 200 dead fish in PEI river There’s an investigation underway in eastern Prince Edward Island after more than 200 dead fish were found in a river.

There’s an investigation underway in eastern Prince Edward Island, after more than 200 dead fish were found in a river.

It all started just off Jessie Maybelle Road on Friday, when Department of Transportation workers clearing a culvert discovered the first dead fish.

“I went right out to the site, with fish and wildlife and the conservation officers,” said Hannah Murnaghan, watershed coordinator for the Morell River Management Cooperative.

“Obviously, to see a fish kill on one of the rivers that we work so hard on, to conserve and enhance habitat for fish, it was super heartbreaking and disappointing.”

The section of the river is known to have a high water temperature, but an extended heatwave early this month put additional strain on the population.

So far, the investigation points to high heat, low oxygen levels, a beaver dam, and heavy rainfall as contributing factors.

“The fish normally have places that they can go and find refuge,” said Rosie MacFarlane, a freshwater fisheries biologist with the P.E.I. government.

“But with the additional height of water from the dam, and then a big flush and release of that water in a heavy rainfall event, it may have overwhelmed the stream below.”

MacFarlane said a relatively short section of the east branch of the Morell River was impacted.

“A series of unfortunate events for sure,” said Murnaghan. “The east branch is already a very warm system, warm branch of the river, and then the heatwave we had didn’t help that at all.”

Since Friday, hundreds of brook trout were pulled from the water, along with a number of smaller species.

However, conditions are improving.

“The oxygen levels have been going up since Friday, quite a bit,” said MacFarlane. “Once the water got moving and flowing freely, and once we got out of that intense heatwave, then we have seen things improve.”

On average, there’s one to two freshwater fish kills per year on the island.

Long-term rehabilitation is now the goal, and the east branch of the Morell River is set to be stocked with 3000 brook trout fingerlings, juvenile fish, in the fall.

The investigation is ongoing, and it will be some time before a definitive cause is determined. There’s no evidence so far that, barring a major heat wave, there will be any more fish kills associated with the event.