Question

which statement best describes an ecological effect of marshes? they deplete groundwater resources. they provide low ecological productivity. they destroy natural flood preventions and erosion control. they filter and clean water before it enters the ocean.

Explanation:

Marshes act as natural filters. They trap sediments, nutrients, and pollutants, purifying water before it reaches the ocean. They do not deplete groundwater, have high ecological productivity, and enhance natural flood - prevention and erosion control.

Answer:

They filter and clean water before it enters the ocean.