Thermal vents occur in places in the deep ocean. These vents bring heat and minerals to the water. Sulfides can be used for energy instead of sunlight and there is a whole ecosystem that depends on this energy source for life. Coral Reefs Coral is disappearing at an amazing rate around the world. Some disappearance may be due to warming water or human waste from the streams.
Coral provides a place for a very rich community of algae that are the basis for the community.
Most corals are in warmer waters, but there are a few species that grow off the coast of California and England in much colder areas. Florida coral banks are in trouble - bleaching and dying out. An Estuary is a partially enclosed coastal bay that has a mix of fresh and salt water. Estuaries are thought to be the most productive ecosystems on earth. Many marine fish use them to lay eggs and they support very large populations of young fish.