Coastal Wetlands

Coastal Wetlands • Land areas covered by salt water at least part of the year are called coastal wetlands • Provide habitat and nesting for fish and wildlife • Absorb excess rain to help prevent flooding • Filter out pollutants and sediments

Plants and Animals of Estuaries • Estuaries support many marine ecosystems • Rivers supply nutrients that have washed from the land • Sunlight and nutrients support large populations of plants and plankton • Larger marine animals feed from estuaries

Threats to Estuaries • In populated areas, they were used as landfills • Pollutants include sewage, industrial waste, and agricultural runoff • Estuaries cannot cope with the excessive amounts of human pollution

Salt Marshes • In estuaries, where rivers deposit mineral rich mud, salt marshes form • Salt marshes support communities of clams, fish, and aquatic birds • Act as a nursery for shrimp, crabs, fish which are then consumed by other ocean animals or people

Mangrove Swamps • Mangroves are several species of small trees adapted for growing in shallow salt water • Mangroves have wide, above-ground root systems for support • Dense growth of mangroves in swampy areas are mangrove swamps • They help protect the coastline from erosion

Rocky and Sandy Shores • Rocky shores have more plant and animal diversity than sandy shores • Rocks anchor seaweed, sea anemone, mussels, and sponges • Sandy shores has abundant life in the water and sandy sediments • Barrier islands run parallel to sandy shores and protect the mainland from storms

Coral Reefs • Coral reefs are limestone ridges built by tiny coral animals called coral polyps that secrete skeletons of limestone that slowly accumulate into reefs • Thousands of species of marine plants and animals live in the cracks of reefs making them among the most diverse ecosystems on Earth • Are only found in shallow, warm salt water

Coral Reefs in Danger • Coral reefs are fragile ecosystems • If the water gets too hot, too cold, too polluted for too long, the algae that live there will move or die--when this happens, the coral turns white and is known as coral bleaching • Bleaching is occurring more frequently now because of human activity

Oceans • Sunlight penetrates only about 100 m (330 ft) • As a result, much of the ocean's life is concentrated here • Seaweed and algae grow anchored to rocks and phytoplankton drift on the surface

Plants and Animals of Oceans • Phytoplankton grows only where there is enough sunlight and nutrients • This makes the open ocean one of the least productive ecosystems • Phytoplankton use oils and air bubbles to keep from sinking to the bottom • The smallest herbivores (jelly fish shrimp, fish larvae) live near the phytoplankton they eat

Deeper in the Ocean • The depths of the ocean are perpetually dark • Most of the food is dead organisms • Decomposers and filter feeders will be found here

Threats to the Ocean • Oceans are steadily becoming more polluted • Runoff from fertilized fields may cause algal blooms • Waste from cities and industries, fertilizers, and sewage are the main sources of pollution • Overfishing is destroying some fish populations

Arctic and Antarctic Ecosystems • Ecosystems are marine • The Arctic Ocean is nutrient rich because of surrounding land masses • The Antarctic is the only continent never colonized by humans • Plankton is the basis for both of these food webs

Copy Now, Answer Later • Explain why estuaries are very productive ecosystems. Why are estuaries vulnerable to the effects of pollution? • Compare salt marshes with mangrove swamps. • Describe two factors that can damage coral reefs. • List two ways in which animals of the oceans are threatened. • Suppose the sea suddenly rose 100 m. What would happen to the world's coral reefs? Explain.

Coastal Wetlands