What is ‘fish kill’ and why it happens
- June 17, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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What is ‘fish kill’ and why it happens
Subject: geography
Section: Physical geography Climatology
Context:
- Thousands of dead fish washed up on multiple beaches in southeast Texas, USA.
Details:
- Among the dead fish covering the shores were mostly menhaden but there were also some sharks, trout, bass, catfish and stingrays.
Fish kill phenomenon:
- The incident took place due to a phenomenon called “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.
- A combination of phenomena led to the occurrence of this event:
- Warm water and rising sea surface temperature led to difficulty in breathing
- Group of fish trapped in shallow water leads to more warming of water
- Calm water: Due to calm water, wind does not get mixed with the water, thus leading to scarcity of dissolved oxygen.
- Due to cloudy skies, phytoplankton were unable to carry out the process of photosynthesis, which is another way of producing oxygen in the water.
- Texas experiences fish kills every year during summers when the temperatures of the sea surface rise.
- With the rising temperature in the oceans, this phenomenon may become more prevalent.