FISH KILL

Disclaimer: Copyright infringement not intended.

Context

• On various beaches of southeast Texas in USA, dead fish numbering tens of thousands were washed up.
• This accentuated the risk of being exposed to bacteria and sharp fins and hence public was asked to stay away from these beaches.

Other Details

• The main type of fish found in these dead fishes was mostly menhaden.
• However other fishes like catfish, bass, sharks, trout, bass, and stingrays were also found dead.

Fish Kill

• The phenomenon when there is sudden and unexpected death of acquatic animals, including fish, due to variety of reasons is referred to as fish kill.
• This phenomenon is usual in Texas during summers.

Reasons for fish kill

• Fish may be suffocated due to reduced and low level of dissolved oxygen in water.

Rise in sea temperature

• It makes ocean water, especially shallow water, warmer and reduce the oxygen holding capacity of water.
• Hence it is difficult for Aquatic animal to breathe.
• This leads to the unexpected and erratic activities of fish which further depletes oxygen in water.
• Hence these deaths are attributed to these extremely low levels of dissolved oxygen.

Calm seas

• There is no mixing of waves and winds.
• It may reduce the dissolved oxygen and leads to the low levels of oxygen.

Cloudy sky

• It prohibits/hampers the process of photosynthesis by phytoplankton.
• Oxygen is generated as the by-product of this process.
• As there is reduced or no sunlight due to presence of clouds, oxygen generation impacted.
• It leads to the low levels of dissolved oxygen available to aquatic animals.

Must read Article:

Warming of Oceans

https://www.iasgyan.in/daily-current-affairs/state-of-the-global-climate-2022-report

https://indianexpress.com/article/explained/everyday-explainers/thousands-of-dead-fish-wash-up-on-texas-coast-what-is-fish-kill-and-why-it-happens-8667424/