Life in the Oceans & Ocean Resources Chapter 20.2 & 20.3

Ocean Chemistry and Marine Life Marine organisms depend on two major factors for survival. Nutrients in ocean water Sunlight

Ocean Chemistry and Marine Life Marine organisms maintain chemical balance of ocean water by: removing nutrients and gases from the ocean returning gases and nutrients to the ocean

Upwelling Deep water is a storage area for nutrients needed for life, BUT, most marine organisms live near surface, so… Nutrients must return to surface through process of upwelling. Upwelling: movement of deep, cold, and nutrient-rich water to the surface.

Upwelling

Marine Food Webs Most organisms live in upper 100 m of water. Plankton: free-floating, microscopic plants and animals are base of complex food web. Consumed by nekton and benthos. Nekton: all organisms that swim actively in open water Benthos: organisms that live on the ocean floor

Plankton

Larger marine animals Nekton: all organisms that swim actively in open water E.g. fish, dolphins, squid Benthos: organisms that live on the ocean floor E.g. oysters, sea stars, and crabs

Nekton

Benthos

Ocean environments Two basic environments Benthic zone: bottom region of oceans and bodies of fresh water Palegic zone: regions of an ocean or body of fresh water above the benthic zone

Ocean zones

Benthic zones Intertidal Sublittoral zone Bathyal zone Abyssal zone Hadal zone

Palegic Zones Zone above the benthic zone Neritic zone Oceanic zone Divided into four zones

Ocean Resources Increase freshwater supply by desalination- the extraction of fresh water from salt water. Methods of desalination Distillation Freezing Reverse Osmosis deslination

The Jubail desalination plant in Saudi Arabia is the largest in the world. The plant produces 800 million gallons per day, while generating 5,000 megawatts of power. Fresh water is a vital environmental resource in the Middle East.

Mineral and Energy Resources Petroleum Found beneath sea floor ¼ of Earth’s oil extracted from offshore wells Trace Minerals Mg and Br—But to extract is too costly Nodules Source of manganese, iron, copper, nickel, cobalt, and phosphates—but recovery difficult and expensive

Food from the Ocean Seafood—important source of protein Harvested from Fishing—important industry but must manage to prevent over-harvesting Aquaculture—the raising of aquatic plants and animals for human use or consumption.

Ocean-Water Pollution Grown worse with growth of world population and increased use of more-toxic substances.

Productive coastal areas and beaches are in greatest danger because they are closest to the source Beach damaged by oil pollution

Filthy Facts website http://www.peopleandplanet.net/doc.php?id=411