Coral is one of the most amazing and beautiful creatures in the ocean. They litter the rocks and floors of the ocean with color and protection for other animals. At first glance, you may think that coral is a type of plant. In some way, you would be right. But, there is a huge difference between plants and coral. Coral is actually more evolutionally related to humans than they are to plants. Coral falls into a very similar category as the sponges you use for cleaning your dishes. They are marine invertebrates in the phylum Cnidaria. The Phylum Cnidaria consists of marine organisms that have specialized cells for capturing prey. This Phylum even consists of Jellyfish. Coral is specifically in the class Anthozoa. This class is a section of Cnidarians that filter water through an internal system of septa and folds in the body leading to a large cavity for digestion.
The reason that pollution is associated with the decrease in coral populations is due to algae. When sedimentation and other objects enter the water it increases the growth rate of certain algae that decrease the quality of water. This decreased quality of water results in coral becoming susceptible to disease, death, and decreases production rates. The death of coral has an overlying effect on creatures of the ocean. Coral provides food for the smallest of animals and even protection. This leads to a snowball effect that can cause disaster for all animals.