The Department of Fisheries, Aquaculture and Environment provided an update Monday on an incident of fish mortalities discovered last Wednesday, July 10.
The incident occurred in the upper end of the Wilmot River in Norboro. It was reported by a member of a conservation group which was doing habitat improvement work in the area of Murphy's Bridge.
Spokesperson Jim Young, director of the Water Resources Division, said results of autopsies on six of the dead fish were received Monday from the Atlantic Veterinary College.
"According to the autopsy report, the fish were in good condition. They were feeding well at the time of death and there were no signs of an infectious disease," Young said. "The report indicates that the condition of the fish was consistent with either acute anoxia or lack of oxygen, which the investigation has ruled out, or a toxic exposure."
Water, sediment and fish tissue samples were sent last week to the Environment Canada laboratory in Moncton for analysis. It is expected to take two to three weeks. Until they receive results of the lab analysis, Young said investigators cannot make any further determination as to the cause of death.
Meanwhile, the initial cleanup on the river was completed Monday. Young reported that investigators collected approximately 4,500 fish in total. The majority of the fish are brook trout. There are also some sticklebacks and a small number of rainbow trout.
"The affected area appears to be a five-kilometre stretch ending in the area of Miller's Pond in Kelvin Grove. Investigators have found live fish in the area between Miller's Pond and Freetown Bridge," Young added.
Approximately 25 people have been working the last several days on the river cleanup. They include members of local conservation groups, a crew with the Young Environmentalists Program, and staff of the Departments of Fisheries, Aquaculture and Environment and Transportation and Public Works.
The Department of Fisheries, Aquaculture and Environment is continuing to investigate the incident in cooperation with Environment Canada and the federal Department of Fisheries and Oceans.