What specific type of wetland is most effective at removing excess nutrients from agricultural runoff?

A freshwater marsh is generally considered the most effective type of wetland for removing excess nutrients from agricultural runoff. Wetlands, in general, are highly effective at nutrient removal due to their unique hydrological and biological characteristics. However, freshwater marshes, characterized by non-woody vegetation like grasses, reeds, and sedges, excel in this function. The shallow water depths and slow flow rates in marshes allow for prolonged contact between the runoff water and the wetland vegetation and soils. This prolo....