Question

select the marsh ecosystem
this ecosystem has:

• water that is low in salt and rich in oxygen
• flowing water
• organisms that swim or stick to rocks

this ecosystem has:

• water that is low in salt
• water that stays mostly still
• more oxygen near the surface than at the bottom

this ecosystem has:

• land that is covered with water for most of the year
• many grasses and few trees
• soil that is rich in nutrients

Explanation:

A marsh ecosystem is characterized by land that is covered with water for most of the year, has many grasses and few trees, and soil rich in nutrients. The first ecosystem described has flowing water (more characteristic of a river - like ecosystem), the second has mostly still water (more like a lake or pond). The third description matches the key features of a marsh.

Answer:

The third ecosystem (the one with land covered with water for most of the year, many grasses, few trees, and nutrient - rich soil) is the marsh ecosystem.