11. Corals build a reef's calcium carbonate structure, which in turn creates habitat for numerous other organisms to live. Explain how human activities are affecting ocean temperatures and how these changes lead to reef destruction and the loss of biodiversity.

Pollution.

Explanation:

Human activities such as burning of fossil fuel increases the production of carbondioxide gas that leads to increase the temperature of the atmosphere as well as the ocean. The warm temperature of ocean causes bleaching of coral reef because the algae present on the coral reefs are removed which turn it into white or colorless corals.  The human activities such as pollution causes destruction of coral reef which leads to the destruction of habitat of  thousands of organisms and as a result loss of biodiversity occurs.

answer; i believe that the correct answer is (light);

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.