Initial results have been received on samples collected during the investigation into fish kills in both the Tryon and Westmoreland River systems. Results from the Atlantic Veterinary College indicate that the sudden death of the fish is consistent with a toxic insult to the fish, and dissolved oxygen and temperature were not believed to be a significant factor.
"Examination of the fish from both sites by the Atlantic Veterinary College indicates that the fish appeared healthy prior to death," said Mitch Murphy, Minister of Technology and Environment.
In Tryon, a number of water and sediment samples were collected and preliminary results indicate the presence of azinphos methyl and carbofuran in water samples from Lord's Pond. Azinphos methyl was found at concentrations that would be considered toxic to fish, while carbofuran concentrations were below aquatic water quality guideline values. Azinphos methyl was also found at toxic concentrations in a pool of standing water collected from a washout gully below a potato field located at the origin of the fish kill. Pesticides were not detected in the preliminary analysis of water or sediment samples from a pool of standing water located a short distance upstream from the suspected field.
In the Westmoreland River, four pesticide products were detected in a standing water sample taken from a gully that was created as a result of runoff from a suspected field. The four products detected were carbofuran, chlorothalonil, endosulfan and metribuzin. Chlorothalonil, endosulfan and carbofuran were all above aquatic water quality guideline values. Chlorothalonil and azinphos methyl were also detected in sediment samples collected during the Westmoreland investigation.
During the investigations, farmers in the affected areas have cooperated fully, and all of the pesticides that were detected in the samples were reported to be used by the farmers.
In the Westmoreland River, stream water samples were not analysed as there had been a significant time lapse between the likely timing of the fish kill and the time the Department of Technology and Environment became aware of the kill.
"The only way to get really good test results is to get samples as soon as possible when there is a fish kill," added Murphy. "I would encourage anyone noticing a number of dead fish to notify the Department's Environmental Emergency Response number at 1-800-565-1633, which is printed in the front of the Telephone Directory."
Additional test results from the various fish kill investigations are expected by late next week.