This section will define and describe coastal ecosystems. Specifically, you will learn:

What is a Coastal Ecosystem?
Does a coastal ecosystem just involve the ocean? What are the components of the ocean's watershed?

Besides oceans and their beaches, a coastal ecosystem can extend for miles beyond its immediate habitat. The streams you see along the picnic areas on the Blue Ridge Parkway flow into rivers, some of which are in the Piedmont area. These rivers in turn dump into an estuary near the coast, a large river of water that mixes the freshwater of the river with saltwater from the approaching ocean. The estuary eventually finds its way to the ocean.

In short, a coastal ecosystem includes the following:

• Streams
• Rivers
• Estuaries
• Beaches
• Oceans
• Marine plants, fish and mammals

The Ocean Watershed

All of the water that drains into the ocean, whether from streams, rivers, lakes, estuaries, wetlands or groundwater, and its surrounding land make up the ocean's watershed. The section on watersheds will give you more information on what watersheds are, how they influence the main body of water and how human actions can affect them.

Ocean Chemistry

Chemistry is really important in studying water quality. When water chemistry changes, the balance of life changes. This section will tell you what the ocean is comprised of chemically and what endangers that balance.

Ocean water is much more than just water and salt; it is home to a number of chemicals and nutrients. Most of them combine to make the salt in the water. Others are present in smaller amounts to maintain the aquatic life. All of them are necessary, but in the right proportions.

A breakdown of the chemical makeup of ocean water would look like this:

Major Chemicals

• Sodium· Magnesium· Calcium· Potassium· Chlorine· Sulfate · Bicarbonate· Strontium· Bromine· Boric Acid· Fluorine

Other Chemicals

• Carbonic acid (undergoes a chemical reaction to form 2 chemicals which regulate the pH and the carbon dioxide levels of the ocean)
• Nitrate and Phosphate (maintain ocean life)
• Iron and Silica (limit the amount of the previous two nutrients)

Problems occur when one or more of these chemicals are out of balance with the others or in higher quantities than they are naturally. Chemical imbalance is often created by nutrient loading, caused when a foreign substance is added to a part of the ocean's watershed.

Oceans can be damaged by two types of pollution:

• point source and
• nonpoint source.

Why We Need Coastal Ecosystems
Besides providing those beautiful sunsets, the ocean is a source of food and recreation. Nearly everyone looks forward to that scrumptious coastal seafood, and surfers and swimmers flock to the North Carolina coast during the summer.

From another perspective, we need the ocean for its diversity of life. Some of the most beautiful species live in ocean habitats. In fact, several endangered species still inhabit oceans and the estuaries that feed them. In addition, coastal and marine environments provide several benefits to people:

• The fishing industry
• Importing and exporting goods
• Tourism
• Mineral extraction from ocean plants