Marine and Freshwater Ecosystems

Marine Ecosystems aka Ocean Ecosystems Abiotic factors that affect marine ecosystems are – Water temperature – Water depth – Amount of sunlight

3 ocean temperature zones Surface zone Thermocline Deep zone Water temperatures vary with latitude – Surface temps at the equator will be higher than surface temps at the poles Water temperatures affect marine animals – Special adaptations, affects if they eat or migrate

Intertidal zone Where ocean meets land Shallow water Exposed to air part of time Animals/plants must be able to survive being exposed to air and to keep from being washed away by waves. – Holdfasts are rootlike structures used to attach to rocks. Some have special “glue”

Neritic zone In between intertidal and oceanic zones Water becomes deeper because the ocean floor starts sloping downward Plankton a major producer in this zone Sea turtles, dolphins, corals, sponges, and colorful fishes

Oceanic Zone Sea floor drops sharply Water becomes much deeper Fishes whales and sharks Organisms have special adaptations to survive the deep water of the oceanic zone (some glow)

The Benthic Zone The ocean floor Deepest parts get no sunlight Very cold Archaebacteria live here in thermal vents Many organisms get food that falls from above Bacteria, worms, urchins thrive here

Coral Reefs Found in warm shallow areas Made of animals called corals When they die, they leave their skeletons behind. New corals grow on these Provide homes for many organisms

Estuaries Areas where fresh water from rivers or streams spills into the ocean Salt content is always changing Organisms have special adaptations for the varying amounts of salinity(saltiness) Rich in nutrients support large numbers of plankton

Sargasso Sea Found in the middle of the Atlantic Ocean Contains rafts of algae called sargassums Many animals living here are the same color as the algae. Camoflauged to hide from predators

Polar Ice The Arctic Ocean and ocean around Antarctica Some animals live on the ice Some live under it

Freshwater Ecosystems Stream and River Ecosystems – May form from a spring or melting snow – Melting snow or spring water runs into streams then tributaries, then rivers, then to the ocean – Shaped by abiotic factors How fast the water moves Temperature light

Freshwater ecosystems Pond and Lake Ecosystems – 3 zones Littoral zone – close to the edge – Sunlight reaches the bottom – Plants and algae grow here – Small animals such as clams, snails, insects, worms, frogs, salamanders, turtles, fish, and snakes Open water zone – Extends from the littoral zone across the top of the water – Goes as deep as sunlight can reach – Bass, lake trout and other fishes live here – Photosynthetic plankton live here Deep water zone – Beneath the open water zone – No sunlight reaches here – Catfish, carp, worms, crustaceans, fungi, bacteria – Feed on dead organisms that sink from above

Freshwater ecosystems Wetland Ecosystems An area of land that is sometimes underwater or whose soil contains a great deal of moisture Marsh – Treeless wetland where grasses grow – Often found in shallow areas along lakes, ponds, rivers, and streams – Plants depend on depth of water and location of marsh – Grasses, reeds, bulrushes, wild rice – Muskrats, turtles, frogs, and birds Swamps – Wetland ecosystem where trees and vines grow – Water moves slow – Willows, bald cypresses, and oaks – Poison ivy vines, orchids, water lilies, – Fishes, snakes, and birds