Marine EcosystemsChapter 7.2

• I. Marine Ecosystems– A. Identified by: presence of salt water

– B. Includes:• Coastal Wetlands• Coral Reefs• Oceans• Polar Ecosystems

• II. Coastal Wetlands- coastal land areas that are covered by salt water for all or part of the time.

–A. Provide habitat and nesting areas for many fish and wildlife.

– B. Absorb excess rain, which protects areas from flooding

– C. Filter out pollutants and sediments

–D. Provide recreational areas for boating, hunting, & fishing

• E. Coastal Wetlands form in Estuaries

Estuaries:•Areas in which fresh water from a river mixes with salt water from the ocean.•Estuaries are very productive ecosystems because they constantly receive fresh nutrients from the river and from the ocean.•Estuaries can support many marine organisms because they receive plenty of light for photosynthesis and plenty of nutrients for plants and animals•Organisms that live in estuaries are able to tolorate variations in salinity because the salt content of the water varies as fresh water and salt water mix when tides go in and out.•Estuaries provide protected harbors, access to ocean and connection to a river. As a result, many of the world’s major ports are built on estuaries.

•Of the 10 largest urban areas in the world, 6 were built on estuaries.•These 6 cities are Tokyo, New York, Shanghai, Buenos Aires, Rio de Janeiro, and Bombay

–F. Types of Coastal Wetlands

–1. Salt Marsh• Develop in estuaries where rivers

deposit their load of mineral rich mud

• Nursery for crabs, shrimp and fish

• Dominated by marsh grasses

–2. Mangrove Swamps

•Dominated by mangrove tree•Protects coast from erosion•2000 species breed & feed here

III. Barrier Islands (rocky & sandy shores)

A. Characteristics

-Run Parallel to shore

-Protect Mainlands

B. Rocky shores

-provide anchorage

C. Sandy Shores

-Dry out with tides

•1. Coastal Wetlands

– A. Limestone Ridges built by tiny coral animals called coral polyps.

– Polyps secrete skeletons of limestone (Calcium carbonate) which slowly accumulates to form the reef

• B. Corals live only in clear and warm salt water where there is enough light for photosynthesis.

• C. Disappearing Coral Reefs!– Coral reefs are productive but fragile

ecosystems.– An estimated 27% of the coral reefs in the

world are in danger of destruction from human activities.

– Oil spills, sewage, pesticide, and silt runoff have been linked to coral-reef destruction.

•2. Coral Reefs

• V. OceansA. Characteristics:

1. Water absorbs light , so after 330ft photosynthetic organisms will not survive

2. Two zones: photic & aphotic

3.Most ocean life is concentrated in the photic zone, which is shallow, coastal waters

• C. Threats to the ocean– Pollution– Over fishing– Fishing methods

•3. Oceans

VI. Arctic & Antarctic– A large amount of

Plankton form the base of the food chain

– Many whales, fish, seals & birds (penguins)

– A lot of the ocean has ice!

•4. Polar Ecosystems

• VII. Almost every person has an impact on aquatic ecosystems. Through understanding how we affect them, we can reduce the negative effects we have!