Question

Reasons for mortality of fishes in winter season in freshwater ponds and its control measures

Answer 1

Because of the difficulty and lack of standard protocol to investigate fish kills, many fish kill cases are designated as having an 'unknown' cause.

Oxygen depletion.

Diseases and parasites.

Toxins.

Algae blooms and red tides.

Biological decay.

Nutrient pollution and eutrophication.

Spawning fatalities.

Water temperature.