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Forests, Fish and Wildlife

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Fish Kill Information and Statistics

Fish Kill Information and Statistics

The Department of Agriculture and Forestry responds to fish kill reports while the Department of Environment, Labour and Justice conducts the investigation in cooperation with other federal and provincial government agencies.

Fish kills can be attributed to both natural and man-made factors. For instance, every spring smelts enter rivers to spawn and some die naturally on their own, occasionally in significant numbers.  Natural fish kills can also be caused by reduced oxygen at certain times of the year such as when oxygen-poor bottom waters mix with the upper layers in coastal ponds.

Fish kills can also result from human activities such as nutrient overloading. Excessive amounts of nutrients can originate from agricultural operations, intensively managed recreationals lands, improperly stored manure and/or septic handling systems. Nutrient loading leads to massive growths of algae, particularly sea lettuce, and when this vegetation dies and decomposes, it consumes the available oxygen in the water.  Algae blooms and resulting anoxic conditions in many estuaries have been blamed for fish and shellfish mortality. 

Pesticide-related fish kills have received the greatest public attention in recent years.  Since 1962, there have been 51 documented fish kills on PEI that were either proven or suspected to have been caused by pesticides.  In almost all recent cases, the product was applied prior to intensive rainfall events that washed the chemical into nearby streams.  Young and mature fish as well as insects, amphibians and other aquautic creatures can experience significant mortality downstream from these events.  However, it is often difficult to obtain conclusive evidence that pesticides have been responsible for a fish kill because of the delay between the actual die-off and the time that the kill is reported to authorities.  


The 1962 to 2011: Island Fish Kill Summary Report and the PEI Fish Kill Map provide readers with a general overview of the number and location of fish kill events on PEI.

2013 Trout River Fish Kill: Preliminary Report

2014 North River Fish Kill: Preliminary Report


In recent years, the Province has required the establishment of mandatory 15m bufferzones along all Island streams and wetlands. This buffer may be grassed or forested but it must create a barrier that helps to prevent chemicals and soil from entering the water during heavy downpours. As well, additional efforts have been made to encourage tree planting along watercourses, place more emphasis on crop rotation, improve soil management practices and increase reliance on integrated pest management.  In 2002, the province also restricted the use of azinphos-methyl (a toxic organo-phosphate) on fields that border waterways.
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