Inconclusive report provides little insight on cause of latest fish kill in P.E.I.'s Montrose River

A preliminary report on a fish kill that occurred on the Montrose River in western P.E.I. this summer shows how the trout population was devastated following the third fish kill there in the past decade.

But the report, from the provincial Department of Environment, Water and Climate Change, does not answer the question as to what caused fish to die in the latest incident, reported in August.

A total of 2,057 dead brook trout and six stickleback were retrieved from a 4.5-kilometre section of the Montrose River after the provincial Department of Justice and Public Safety was told about the fish kill there on Aug. 28.

According to the report, testing of water samples identified levels of barium, calcium, manganese, sulphate, nitrate and total nitrogen that "would be considered high, although not at levels toxic to aquatic life."

When officials returned two weeks later to assess the overall impact on fish populations in the river, they found there were almost no trout left.

An electro-fishing expedition Sept. 10 netted just five fish, representing a density of 3.9 trout per hundred square metres, "much lower than what would be expected in a stream of this size," according to the report.

Normally on P.E.I. the density of fish in a similar waterway would be 12 times higher, the report notes, while some densities have been recorded more than 100 times that level.

Local watershed co-ordinator John Lane noted how more than half of the dead fish collected were fry — smaller than eight centimetres — with most of the larger fish having been killed off in previous fish kills.

What we want to know is that it doesn't happen again.— John Lane

"The brook was just starting to regain the ground that it lost in the previous fish kill," he said. "These were the future of the stream. And we cut that future short again. So we're back to Square 1."

Lane noted there was no definitive cause identified, nor were there charges laid following fish kills along the same waterway in 2010 and 2017.

Lane said it's important to figure out what caused it to happen this time "because if we know what it is, we can prevent it from happening again."

He said whether anyone is charged or fined as a result "is government's problem. What we want to know is that it doesn't happen again."

Cousins Pond fish kill also investigated

A second preliminary report from the province looked at a fish kill reported in June near Cousins Pond.

In that incident, 530 dead brook trout were collected over a 2.5-kilometre stretch of stream flowing into Cousins Pond on P.E.I.'s North Shore.

A farmer had discovered liquid manure leaking from a pipe into the stream.

Necropsies conducted on 10 of the dead fish found that they had eaten recently, and thus likely were "healthy prior to a sudden death."

The necropsy report noted all 10 fish "smelled strongly of domestic animal manure."

A spokesperson for the province said "there may or may not be charges pending" in relation to both incidents.

We seem to be doing the same thing over and over again, and expecting a better result— John Lane

A request by CBC to speak with an official from the Department of Environment was declined out of concern an interview "could interfere with any judicial process."

Provincial and federal investigations are continuing.

According to the Montrose report, no necropsies were conducted on any of the 2,057 fish recovered there because the bodies were too decomposed.

However, the report notes that federal investigators sent water and fish samples for analysis to a lab in Moncton, N.B.

There was no response to a request by the CBC for an update on the federal investigations.

The Montrose River received a failing grade in the province's most recent water-quality report card, with that report citing high nitrate concentrations, frequent runoff problems and regular anoxic events.

The report on this year's fish kill found there was adequate oxygen in the water. It also noted significant rainfall three days before the fish kill was reported, with 22.6 millimetres reported in Alberton and 48.3 millimetres in Summerside on Aug. 25.

Lane said if anything positive has come from this, it's that the Montrose River was restocked this fall with 3,700 trout fry. "But it's only good if there's no more fish kills."

After watching this happen three times in the same area over the past decade, he said it's time for the province to come up with more stringent regulations in terms of planting in buffer zones and on sloping land in order to better protect waterways. 

"We seem to be doing the same thing over and over again, and expecting a better result," he said.

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