Which is an abiotic factor that affects a freshwater ecosystem?
a. the number of fish
b. the competition for food
c. the amount of light
d. the number of predators

C. The amount of light

Explanation:

Abiotic factors are the non-living factors including the soil, water, sunlight and others. These factors affect both positively and negativity the living species in an ecosystem.

The amount of light is the abiotic factor that will affect the freshwater ecosystem. The light is required by the plants or other autotrophic organisms for the process of photosynthesis. These autotrophs produce food over which the diversity of aquatic fauna is dependent. Therefore, the amount of light available to distinct zones of the water body is important in order to sustain life of those organisms living in the zones.

If the amount of light is more this may lead to drastic increase in the temperature of the water body. The increase in the temperature may not prove to be suitable for the survival of the living species in water.  

it's anything that aren't producers and consumers.

explanation:

you've got to be clear on what "this" is

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