Coral reef communities develop primarily in shallow, low-nutrient, tropical waters. Coral reefs are formed by coral polyps, which excrete the solid calcium carbonate skeleton that makes up the reef. A particular algae lives within the coral polyps and provides the polyps with nutrients from photosynthesis. Nutrients released by the algae and coral polyps are then filtered by sponges, forming the base of the coral reef community food chain which also includes fish, crustaceans, mollusks, and sea turtles. Coral reefs can be damaged when an excess of nutrients, like nitrogen and phosphorus, enters the water through pollution. When this happens, the algae and the polyps die, and the coral skeleton eventually collapses. After a coral reef collapses, which organisms are most likely to succeed the coral in this ecosystem?

In actuality, no organism will be able to replace the coral reefs.

Explanation: The climate change has made the waters warmer, this has hit the coral reefs really bad, they tend to lose colour and the capability to produce food. The coral reef tend to get bleached. They can struck to

- disease

- algae      

- death

The acidification has increased the absorption of carbon dioxide which has compounded in the bleaching problem too.

when you think of the collapse, perhaps only corals which have developed a high resistance to the heat as well the acidification may remain but will they be the same. The answer is a no. None of the organisms or ecosystem can make up the functionality of the coral reefs.  

d. planting trees

the trees take in carbon to make oxygen.

the atomic number of magnesium is 12. its nucleus must contain 12 protons and no electrons. the atomic number of an atom is determined by the number of protons.

magnesium is an electrolyte injection commonly used to treat low magnesium levels in your blood. it is also used to prevent or control seizures in women with preeclampsia or eclampsia.