The Marine Biome

1. The Marine Biome CHAPTER 11

2. 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

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

4. 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

5. 11.2 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. Coastal 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

12. Coastal 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

13. 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.