The Marine Biome CHAPTER 11

THE WORLD OCEAN OCEANIC ZONE – Open ocean Largest zone in the ocean – 90% of surface area Very deep – 500 m to 11,000 m Mostly aphotic except over the continental shelf Photic zone less than 100 m deep only producers are phytoplankton

The Oceanic Zone Neritic zone – photic area over the continental shelf Aphotic zone - has limited diversity Benthic zone – scavengers that eat detrius (dead organic material) or marine “snow” Organisms live in open ocean have special adaptations

The World Ocean Water near the equator is warmer, has more salt and minerals Water currents are driven by winds Most currents are stable like the Gulf Stream (warm water along the East Coast of the U.S.) Exceptions – La Nina, El Nino

10.2 Neritic Zone All continents are surrounded by shallow water - continental shelf Neritic Zone - From the continental shelf to the top surface of the water. Shallow depth so it is in the photic zone. Warmer water has coral reefs combination of animals and bacteria Colder water has kelp beds

Coral Reefs “Tropical rainforest” of the marine biome Reef is made from millions of shells from tiny corals – like sea anemones Greatest marine biodiversity Only the top layer of corals are alive Reefs protect the shoreline from erosion Largest reef is Great Barrier Reef off Australian coast

Coral Reefs Living corals have tiny algae in their bodies Algae perform photosynthesis to give them food – mutualism Algae need sunlight for photosynthesis Coral are limited in depth to photic zone Reef damage from human activity: blowing up so big ships can pass through, coral is used for jewelry and to decorate fish tanks, water pollution from ocean dumping, runoff from farmland

Kelp Forest Kelp beds or kelp forests are usually found in colder water. Large beds off the California and Alaskan coast Kelp forests are home to many species – like the coral reefs Kelp are sea algae that grown in very tall columns from the continental shelf to the surface

Estuaries Region where fresh water from a river meets salt water from the ocean Subject to rise and fall of tides Water is usually brackish Provide shelter and a place for many marine animals (fish and birds) to lay their eggs When the young hatch they can ride the current back out to sea The The largest estua The largest estuary is the Che

Intertidal Zones Located along the shoreline of every continent Covered and uncovered by ocean water twice a day (Tides). Organisms adapt to changing tides and pounding surf by either burrowing in the sand or attaching to rocks Attached to wetlands such as salt marshes or mangrove swamps

Costal Salt Marshes Flat, muddy wetlands around estuaries, bays and lagoons Wet at high tide and dry at low tide Vital “rest-stop” for migrating birds Grasses provide organic matter (detritus/marine “snow”) that is the base of all ocean food chains Sediments from fresh water collect and cause delta areas to sink under water changing their shape - Subsidence

Costal Salt Marshes Sediments from fresh water wash downstream and collect at the mouth of the river - Accumulation The buildup will cause delta areas to sink under water changing their shape – Subsidence The Mississippi River delta(40% of all US wetlands) goes through a 5000 year cycle of accumulation-subsidence that changes the shape of the delta

Mangrove Swamps Coastal wetland found only in warm climates Woody plant/tree more than 800 species worldwide - only 10 found in the USA (red mangrove is most common) Low-oxygen water causes roots to lift up out of the water The tall roots trap sediment which collects and forms soil for other plants to grow Eventually the mangroves collect enough soil to replace the water become a forest.