2000 was another bad year for fishkills on PEI.

Profit's Pond Test Results Released

July 28, 2000

CHARLOTTETOWN, PEI -- The Department of Fisheries, Aquaculture and Environment released results Friday of pesticide analysis of samples collected from the Profit's Pond semi-natural salmon and trout rearing facility in West Prince.

Samples were collected as part of an investigation into fish mortalities that occurred earlier this month in two holding tanks which draw water from the pond.

Clair Murphy, Director of the Department's Water Resources Division, released the results of the pesticide analysis. He said a sample collected from the fish tank where approximately 1,500 four to six-inch brook trout died showed low levels of metribuzin, a pre and post-emergent herbicide used for weed control; and chlorothalonil, a commonly-used fungicide. A second sample collected from the centre of Profit's Pond, where some 39,000 salmon par are kept, showed a low concentration of metribuzin.

Murphy said the concentration of both chemicals was low compared to the acute toxicity levels for trout.

"The Canadian Water Quality Guidelines for the Protection of Freshwater Aquatic Life indicate that the acute toxicity level for metribuzin is 42,000 to 76,000 parts per billion (ppb). The highest concentration of this compound was found in the fish tank at 0.6 ppb. A concentration of 0.3 ppb was found in the pond."

With regard to chlorothalonil, Murphy said the acute toxicity threshold for trout is 250 parts per billion. The concentration found in the fish tank was 3.3 ppb, and there was no detection of the fungicide in the pond water.

"Based on the Aquatic Life Guidelines, the concentrations of pesticides found in the samples analyzed would not represent a health risk to fish," Murphy said.

Workers at Profit's Pond discovered the fish mortalities the morning of July 18. Somewhere in the range of 5,000 to 6,000 fish were lost. Murphy noted there was a heavy rain July 17 which resulted in the water having high suspended sediment content.

Results of autopsies conducted on the dead fish at the Atlantic Veterinary College earlier this month indicated that the primary cause of death was acute gill disease.

Where the functional capacity of gill tissue to transfer oxygen from the water into the blood stream is impaired by gill disease or some other factor, the fish eventually suffocate. Murphy explained any environmental factors such as high levels of suspended sediment or reduced dissolved oxygen levels in the water would further reduce the gill efficiency.

"Both fish tanks, as well as the pond water, showed high levels of suspended sediment during the event. There was also some evidence to suggest the dissolved oxygen levels may have been somewhat reduced," he said.

Murphy indicated the investigation of cropping activities in the Long Creek watershed upstream of Profit's Pond has not revealed clear evidence of serious runoff from any particular location.

"Investigators have talked with several farmers in the watershed and have received excellent cooperation," he added.

The investigation is continuing.

Souris River Tests Results Released

August 3, 2000

The Department of Fisheries, Aquaculture and Environment released results Thursday of pesticide analysis of water samples taken from the Souris River where several hundred fish died last month.

A stream enhancement crew discovered the dead fish in the east branch of the Souris River in the Harmony Junction area the morning of July 20. Investigators collected approximately 300 fish in excess of four inches, including rainbow trout, speckled trout and salmon. A number of smaller fish were also lost but were not counted.

Bruce Raymond, head of rivers and estuaries in the Department's Water Resources Division, released the results of the pesticide analysis. "Two agricultural pesticides were detected in water samples collected during the investigation," Raymond stated in a news release.

Lab results from the Atlantic Veterinary College toxicology lab showed a concentration of dithiocarbamates and metribuzin in the water samples.

Raymond explained dithiocarbamates are a group of pesticides which include mancozeb, the active ingredient in a fungicide which was reported to have been sprayed in the area the morning before the fish mortalities were discovered.

"The maximum concentration of dithiocarbamates in the water samples, which were collected 30 hours after a rainfall, was 131 parts per billion(ppb). Concentrations may have been higher at the time of death," he said. "Compared to reported toxicity values, this concentration is of concern for fish health."

With regard to metribuzin, a herbicide used for weed control, Raymond said the lab results showed a maximum concentration of 9 ppb in the water samples. He added this concentration is below that considered to be of concern for fish health.

Raymond noted there was heavy rain in the Souris area the morning of July 19, the day before the fish mortalities were discovered. "Between 9 and 10 a.m., there was 7 mm of rainfall, with 6.2 mm of rain falling in the short span of nine minutes," he said.

Raymond said a farmer in the area reported he had applied mancozeb immediately prior to the rainfall. The farm weather forecast for Souris that morning was a 29 per cent probability of rain between 5 and 8 a.m. with zero per cent probability after that.

In other results of the investigation, Raymond indicated water temperature and dissolved oxygen levels in the water were normal.

Department Investigating Fish Mortalities

August 10, 2000

CHARLOTTETOWN, PEI -- The Department of Fisheries, Aquaculture and Environment is investigating three separate incidents of fish mortalities discovered Wednesday.

The department received reports of dead fish in Indian River and French River Wednesday afternoon and a third report of dead fish in Mount Herbert that evening.

Spokesperson Bruce Raymond, head of the Department's Rivers and Estuaries Section, said reports of the incidents in Indian River and French River came in at approximately 2 pm. Raymond said a watershed crew discovered the dead fish in Indian River, while a member of the public reported the incident in French River.

The report of fish mortalities in Mount Herbert came in the form of an anonymous call to the toll-free Environmental Emergency Response number (1-800-565-1633).

In all three incidents, Raymond said investigators have collected water samples as well as dead fish to be taken to the Atlantic Veterinary College for analysis. The first samples were collected in Indian River at approximately 2:30 pm.

"At this point, it appears water temperature and dissolved oxygen were not factors in the fish mortalities in either Indian River or French River. It is still too early to make that determination in Mount Herbert," Raymond said.

"Beyond that, until we receive the results of the fish autopsies and water sample analysis by the Atlantic Veterinary College we cannot determine what was the cause of death in any of the incidents," he added.

The provincial Department of Fisheries, Aquaculture and Environment is continuing the investigations in cooperation with Environment Canada.

Results of Pesticide Analysis Released

August 31, 2000
CHARLOTTETOWN, PEI -- The Department of Fisheries, Aquaculture and Environment has received results of pesticide analysis of samples collected during the investigations into three incidents of fish mortalities earlier this month.

The department received reports of dead fish in Indian River, French River and Mount Herbert August 9.

In Indian River, approximately 2,500 trout were collected over a two-kilometre stretch of stream. There was a heavy rainfall in the area the day before the fish were discovered, with the weather station in Kensington reporting 16.2 mm of rain.

As part of the investigation into the fish mortalities, water, sediment and fish samples were collected and taken to the Atlantic Veterinary College (AVC) for analysis.

Clair Murphy, director of the department's Water Resources Division, said results from the AVC toxicology lab indicate pesticides were detected in water samples taken from two locations in Indian River.

At the uppermost sampling location, Murphy said a number of pesticides were detected in a sample taken from a pool of standing water adjacent to the stream. However, the concentrations were all well below levels which would be toxic to fish.

The second samples were taken from a pool of standing water at the base of a large drainage area approximately 350 metres above the main stream. Murphy said a number of products were detected with two insecticides, azinphos-methyl and endosulfan, being present at high concentrations.

Murphy said the concentration of azinphos-methyl was measured at 73.2 parts per billion (ppb), which is several times greater than reported toxicity values. The concentration of endosulfan at 8.2 ppb was also several times higher than reported toxicity levels.

"Given the concentrations of these insecticides in the pool of standing water, it is quite probable surface water runoff containing pesticides reached the main stream," Murphy said.

Samples collected from the stream itself did not show any significant levels of pesticides, but Murphy said that is to be expected.

"The dead fish were discovered approximately 24 hours after the heavy rainfall so anything that was present in the stream water would have been flushed through the system by the time the investigation could be initiated," he explained.

Murphy said the autopsies of the fish specimens did not provide conclusive information as to the precise cause of death. Although the fish had begun to decay prior to their collection, autopsy observations were consistent with death by anoxia or a toxic event, he said.

"The examination of the stomach contents did suggest that the fish were eating normally prior to death," Murphy noted. "In addition, the lab report indicates that there was no evidence of infectious disease in the fish."

In Mount Herbert, the report of dead fish came to the toll-free Environmental Emergency Response number late in the evening of August 9. A total of 58 fish were collected: 42 trout, from four to 23 cm in length, and 16 sticklebacks.

Murphy said the investigation focused on a carrot field on Fullerton's Creek which showed evidence of runoff and erosion. There was no standing water from which to take samples during the initial investigation. However, investigators took sediment samples from the field, the buffer zone between the field and the stream, and the stream itself.

As well, Murphy said a thunder storm moved through the area when investigators were on site and they were able to collect samples of runoff water.

Murphy said the report from the AVC toxicology lab indicates that three compounds, one fungicide and two herbicides, were detected in both the sediment samples and runoff water samples.

"The fungicide, chlorothalonil, was found at moderate to high concentrations in relation to its toxicity levels, while the herbicides, linuron and prometryn, were detected at low concentrations relative to their toxicities to fish," he added.

No pesticides were detected in the water samples taken from the stream.

Murphy said autopsies of the fish specimens from Fullerton's Creek indicate that the deaths were sudden, most likely the result of anoxia or the introduction of a toxic substance. There was no sign of infectious disease, he said.

In the case of the fish mortalities in French River, a total of 50 trout, from five to 40 cm in length, were collected August 9. Two kilometres east of where the dead fish were discovered, more than 50 mm of rainfall was recorded over a period of approximately 35 minutes the previous evening.

Murphy said the lab reports on French River indicate trace amounts of pesticides were detected in sediment samples and samples of foliage taken from a suspect field. No pesticides were detected in the water samples or sediment samples taken from the stream.

Murphy said autopsies of the fish specimens from French River again indicate the deaths were sudden, most likely the result of anoxia or the introduction of a toxic substance.

The Department of Fisheries, Aquaculture and Environment is continuing the investigation into all three incidents of fish mortalities.