APES 8.4 Human Impacts on Wetlands and Mangroves

Definition: Areas where soil is submerged in water for all or part of the year.
Emergent Vegetation: Plants with roots anchored in soil, parts extend above water.
- Adaptations needed to survive in wet conditions.
- Comparison to crops which can drown if roots are submerged.

Ecosystem Services: Vital functions provided by wetlands.
- Provisioning Services: Habitats for animals/plants; sources of food/raw materials.
- Regulating Services: Groundwater recharge and filtration of pollutants.
  - Wetland plants trap and metabolize pollutants.
- Carbon Sequestration: Storage of CO2 in woody plants, mitigating climate change.
- Supporting Services: Water filtration and nutrient recycling through breakdown of organic matter.
- Pest Control: Natural predators in wetlands help manage pest populations.
- Cultural Services: Tourism, recreational activities, research opportunities, economic benefits.

Pollution: Nutrient pollution along with sediment, pesticides, and motor oils impacting water quality.
Development: Filling or draining wetlands for urbanization can destroy habitats and services.
Water Diversion: Reduction of water levels through diversion for agriculture/drinking; affects ecosystems downstream.
- Example: Everglades – historical vs. diverted water flow affecting habitats.
Hydroelectric Power: Dams can trap sediment and vital nutrients behind barriers, altering soil fertility downstream.
Overfishing: Disruption of food webs leading to instability in wetland ecosystems.

Value of Mangroves: Estimated at $800 billion due to ecosystem services.
Key Ecosystem Services:
- Fuel Source: Sustainable harvesting opportunities in developing nations.
- Coastal Protection: More effective than human-made barriers against storms and floods.
- Water Filtration: Helps clean pollutants and recharge groundwater.
- Tourism: Attracts visitors, providing economic opportunities.
- Habitat for Biodiversity: Supports numerous fish and shellfish species.
- Carbon Sequestration: Crucial for climate regulation.

Deforestation: Clearing for development; beachfront property value leads to habitat loss.
Aquaculture: Creating fish/shellfish farms results in mangrove destruction.
Rice Paddies: Placement of agricultural fields in mangrove areas.
Pollution: Sediments clogging roots and heavy metal toxicity degrading health of mangroves.

Nutrient Reduction Strategies:
- Cover Crops: Planting between main crops to prevent sediment/fertilizer runoff.
- Animal Manure Management: Better containment and processing of manure.
Riparian Buffers: Vegetation along waterways to filter and absorb runoff pollutants.
Sewage Management:
- Upgrade septic systems for efficient drainage and natural filtering.
- Biological waste removal by microbes to reduce nutrient loading in water bodies.