The problem of anoxic rivers is becoming chronic on P.E.I., and has hit the province early this year.
The Montrose River in West Prince is the first this summer to be reported anoxic. Anoxic rivers used to be an August phenomenon, but a dozen or more events in July is now commonplace.
Rivers become anoxic when there are too many nutrients in the water, mostly from farming activity and sewage. The nutrients cause massive blooms of vegetation, which then die and rot. That rotting process sucks oxygen from the water, choking animal life such as fish and shellfish.
"It is of course a great concern and it has been happening on a regular basis over the last number of years," said provincial biologist Cindy Crane.
"The solution is to do something as far as nutrient inputs, to start looking at that and trying to reduce, and get below that threshold that causes these kinds of events."
By July 21 last year 15 estuaries on the Island had been reported as anoxic.
Crane said the province is looking for help in locating anoxic events. Anoxic rivers turn grayish white or green and stink. Crane is asking people to contact the Environment Department if they see these signs in a river.