1. the nutrient availability of aquatic ecosystems is the?
amount of nitrogen, oxygen, and other elements dissolved in the water.
number of other organisms present in the water.
amount of rainfall the water receives.
number of different animal species living in the water.

2. freshwater ecosystems that often originate from underground sources in mountains or hills are?
estuaries.
rivers and streams.
lakes and ponds.
wetlands.

The right options are;

1. amount of nitrogen, oxygen, and other elements dissolved in water.

2.wetlands.

The nutrient availability of aquatic ecosystems is the amount of nitrogen, oxygen, and other elements dissolved in the water.

Nutrients are chemical elements, and sources of nourishment that are important to the development of plant and animal life. In healthy aquatic ecosystems such as rivers, nutrients are required for the growth of the organisms in the entire aquatic ecosystem. The most common nutrients in aquatic ecosystems include oxygen, nitrogen, and phosphorus.

A wetland is an ecosystem that is covered by shallow water, either periodically or permanently. Wetlands usually emerge from underground sources in mountains or hills.