Describe how wetlands contribute to water quality and pollutant removal.

• A. Wetlands trap sediments, absorb nutrients, and enable microbial degradation, improving water quality
• B. Wetlands release nutrients into waterways
• C. Wetlands have no effect on water quality
• D. Wetlands increase turbidity without affecting pollutants

Answer: (A)

Wetlands act as natural water filters, using plants, soils, and microbes to clean water as it moves through them. When water slows down in a wetland, sediments and any attached pollutants settle out, so turbidity and suspended solids decrease. The plants in wetlands take up nutrients like nitrogen and phosphorus from the water, reducing nutrient pollution that can fuel harmful algal blooms. The wetland soils host diverse microbes that break down organic pollutants and transform nutrients through processes like denitrification, which converts nitrates into harmless gases. Together, these physical, chemical, and biological processes remove or neutralize many contaminants, improving overall water quality.

The other statements don’t fit those functions: releasing nutrients would worsen water quality, not improve it; claiming wetlands have no effect ignores the filtration and biological actions they perform; increasing turbidity while not affecting pollutants contradicts the sediment-trapping and nutrient-removal roles wetlands provide.