Question

practice quiz: biomes and aquatic ecosystems (lms graded)
a team of deep - sea divers and biologists is exploring the open ocean. as team members dive downward from the surface, they observe significant changes to the ocean community at a depth of about 200 meters. what is the main cause of the changes at this depth?
a. loss of brightness of the water
b. increasing salinity of the water
c. increasing temperature of the water
d. decreased oxygen concentration of the water

Explanation:

As divers go down to 200 meters in the ocean, light penetration decreases significantly. Light is crucial for photosynthesis by phytoplankton and other primary - producers, which form the base of the ocean food web. Changes in light availability lead to changes in the ocean community. Salinity does not change drastically at this depth, water temperature generally decreases with depth, and oxygen concentration is not the main factor causing changes at this relatively shallow deep - sea depth compared to light.

Answer:

A. loss of brightness of the water