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.