Q. Which of the following factors are responsible for coral bleaching?

1. Increased or reduced water temperature
2. Over fishing
3. Increased solar irradiance
4. Changes in salinity

Select the correct option from the codes given below:
Answer: 1, 2, 3 & 4
Notes: All the above factors are responsible for coral beaching. Elevated sea temperatures are the biggest culprits when it comes to coral bleaching. El Niño also plays a role in heating up ocean waters. Over fishing results in increase in zooplanktons which results in low availability of oxygen leads to death of corals. Extra-bright sunlight, especially when combined with the aforementioned extra-warm seawater another important cause of coral bleaching.

This question is part of UPSC Daily 20 MCQ Series Course on GKToday Android app.