Eutrophication

eutrophication

excessively enriched with nutrients (nitrates and phosphates) triggering rapid algae bloom, aquatic plants, disrupting the natural balance of ecosystem

→ human activity has accelerated the process

The Process of Eutrophication

1. Nutrient Input: Excess nitrates and phosphates enter water bodies

2. Algal Blooms: dense mats on the water's surface.

3. Light Blockage: (causes submerged plants to die)

4. Decomposition: Dead algae and plants are decomposed by aerobic bacteria, which consume large amounts of oxygen.

5. Oxygen Depletion: leads to hypoxic (low oxygen) or anoxic (no oxygen) conditions.

6. Ecosystem Collapse

Managing Eutrophication

1. reducing nutrient input (buffer zones, efficient fertilisers)

2. facilities that remove nitrates and phosphates

3. legislation

4. public awareness

5. restoring affected ecosystems

6. upgrading wastewater treatment plans

7. removing excess algae & nutrients

how to restore affected ecosystems ?

1. Aeration: Pumping air into water bodies to increase oxygen levels.

2. Dredging: Removing nutrient-rich sediments from lake beds.

3. Biomanipulation: Introducing species that control algal growth, such as herbivorous fish.

sources of excess nutrients

1. agricultural run-off

2. sewage discharge

3. industrial pollution

4. atmospheric deposition (nitrogen from vehicle emissions and industrial activity)

how is Eutrophication a Positive Feedback Loops

Excess Nutrients (Nitrates & Phosphates) ↑ → 2. Phytoplankton Growth (Algal Bloom) ↑ → 3. Sunlight Blocked, Oxygen Production ↓ → 4. Algae Die, Decomposers Increase → 5. Oxygen Consumption by Decomposers ↑ → 6. Dissolved Oxygen Levels ↓ (Hypoxia/Anoxia) → 7. Fish & Aquatic Life Deaths ↑ → 8. Decomposing Dead Organisms ↑ → 9. More Nutrients Released → Cycle Repeats (Positive Feedback

How Eutrophication Affects Ecosystem Services

1. fisheries-decline in fish population

2. recreation: loss of recreation opportunities

3. aesthetic: degradation of natural beauty

4. health: risk to human and animal health

→ tourism, water treatment (costs rise), fisheries, biodiversity loss

removal of pollutants and ecosystem restoration

1. sediment removal

2. bio manipulation and reintroduction of native species

3. artificial aeration and oxygenation