What were the causes of fish kills in your lakes, rivers, coastal waters and oceans? 


Fish kills can be defined as any sudden and unexpected mass mortality of wild or cultured fish over a short period of time. It could be due to pollution or contamination of waters or a combination of natural and human-induced stresses in the environment. Climate change (rise in temperatures) and projected increase in the frequency of algal blooms may also increase fish kills.

Fish kills can occur due to a number of reasons including the following: abrupt change of temperatures (winter fish kills/summer fish kills), accidental spills; acid mine drainage (AMD), acid sulfate soils (wetlands and floodplains), algal blooms (cyanobacteria, dinoflagellates), ammonia (NH3) toxicity, anoxia, black water events, bush fire ash, crowding, climate change (rise of temperature), cold water pollution, cold stress, dam operation, dissolved solids, diseases, droughts, environmental stress, eutrophication, floods, herbicides, high temperature stress, hydrogen sulphide (H2S) toxicity, hypoxia, life cycle event, low temperature stress, metals (toxic), municipal sewage, oil spills, nutrient pollution, overturn of lakes, pesticides, pH (low), parasites, power generation water discharge, red tide, salinity, spawning activities, toxins, turbidity, underwater explosions and upwelling.

Fish kills are very visible events which cause considerable interest and concern to the public. Fish kills could be an indicator of environmental stress, a declining of aquatic ecosystems health or water quality problems or water pollution or contamination of water etc.

Question: What were the causes of fish kills in your lakes, rivers, coastal waters and oceans?