marine ecosystem

Marine Ecosystems are the largest systems on the planet, covering over 70 percent of the Earth's surface and constituting over 99 percent of the living space on the planet (area x depth). These vast ecosystems are composed of many different habitats which extend from the near shore regions to continental shelves and the deep ocean. They are home to millions of species and provide food, income, protection, and many other vital ecosystem services to billions of people around the world.
ECOLOGICAL ADVANTAGES
Climate moderation
CO2 absorption
Nutrient cycling
Waste treatment and dilution
Reduced storm impact (mangrove, barrier islands, coastal wetlands)
Habitats and nursery areas for marine and terrestrial species
Genetic resources and biodiversity
Scientific information
ECONOMIC ADVANTAGES
Food
Animal and pet feed (fish meal)
Pharmaceuticals
Harbors and transportation routes
Coastal habitats for humans
Recreation
Employment
Offshore oil and natural gas
Minerals
Building materials
Types of Marine Ecosystems
Estuaries
Salt marshes
Rocky shores
Sandy Shores
Coral reef
Mangrove swamp
Barrier islands
Estuaries
An area in which fresh water from a river mixes with salt water from the ocean; a transition area from the land to the ocean. Other names: bay, sound, lagoon, harbor, or bayou.

Characteristics of Estuaries
Water is brackish : a mixture of freshwater and saltwater
There is a gradual increase in salinity as you go from the river (0-5ppt) to the middle of the estuary (5-25ppt), to the ocean (>25 ppt).
(ppt = parts per thousand, a unit for salinity)
Pollutants are absorbed in estuaries.
Very nutrient rich ecosystems  leads to high productivity and high biodiversity.
Fast-moving rivers and waves carry nutrient-rich particles.
Sediment settles out in the estuary when the water slows down.
Nutrients accumulates on the bottom (benthic zone).
Great place for plants to grow!
Important functions of estuaries: for living