Why in the News
- A study in AGU Advances highlights declining oxygen levels in mangrove waters due to rising CO₂.
Key Concept: Hypercapnic Hypoxia
- Condition of: High CO₂ + Low dissolved oxygen
- Occurs in: Mangrove estuaries (especially low tide, tropical regions)
Major Findings
- By 2100:
- Oxygen ↓ 5–35%
- CO₂ ↑ 8–60%
- Events will:
- Become 15× more frequent
- Last longer (12–24 hours at 78% sites)
Impact on Ecosystem
1. Fish Nurseries at Risk
- Reduced safe time for fish entry
- Decline in juvenile fish survival
2. Biodiversity Loss
- Shift away from: Large reef-associated fish
- Affects commercially important species
3. Fisheries Impact
- Mangroves: Support ~20,000 extra fish/ha/year
- ~4 million fishers depend globally
| [2012] The acidification of oceans is increasing. Why is this phenomenon a cause of concern? The growth and survival of calcareous phytoplankton will be adversely affected. The growth and survival of coral reefs will be adversely affected. The survival of some animals that have phytoplanktonic larvae will be adversely affected. The cloud seeding and formation of clouds will be adversely affected. Select the correct answer using the code given below: (a) 1, 2 and 3 only (b) 2 only (c) 1 and 3 only (d) 1, 2, 3 and 4 |
