Fish Kill

Facts for Prelims

Fish Kill

News: Recently, thousands of dead fish were seen on Texas coast. The phenomenon took place due to what is called as ‘Fish Kill’.

What is Fish Kill?
• It is the sudden and unexpected death of many fish or other aquatic animals over a short period and mostly within a particular area. It occurs mainly due to low levels of dissolved oxygen in the water that causes suffocation of the fish.

What are the factors that cause the phenomenon?
• First was the warm water. When sea surface temperatures rise, it becomes difficult for the fish to breathe as oxygen dissolves easily in colder water in comparison to warmer water.
• Another factor that contributed to the Texas fish kill was calm seas. Experts suggest that one of the ways for oxygen to enter the water is by mixing with wind and waves. But in the past few weeks, the waves along the Texas Gulf Coast have been very calm, causing the depletion of dissolved oxygen.
• Overcast weather was another reason as due to cloudy skies, phytoplankton were unable to carry out the process of photosynthesis.