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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 detritus (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

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

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

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

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

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.