Salt Water

saltwater

97% of earth’s water is saltwater; includes oceans and marine ecosystems

neritic zone

near shore where 90% of ocean life lives due to high nutrients

oceanic zone

open ocean far from shore; deep water with fewer nutrients

photic vs aphotic

photic has sunlight and photosynthesis; aphotic is dark with little plant life

benthic zone

deepest ocean layer; dark, cold, and difficult to study

why life near shore

rivers bring nutrients → feeds plankton → supports big food chains

upwelling

cold nutrient-rich water rises and creates major fishing areas

coral reefs

made of coral polyps; biodiverse but sensitive to warming and pollution

mangrove swamps

salt-tolerant trees in warm coasts; roots give shelter for fish and birds

key idea

oceans support food, oxygen, and climate; many zones are sensitive and need protection