THE GLOBAL OCEAN. global ocean. huge, continuous body of salt water that surrounds the continents covers almost ¾ Earth s surface

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1 THE GLOBAL OCEAN Ø Ø global ocean Ø Ø huge, continuous body of salt water that surrounds the continents covers almost ¾ Earth s surface divided into 4 sections separated by continents 1. Pacific (largest: 1/3 Earth s surface & ½ water) 2. Atlantic 3. Indian 4. Artic Ecology - Ocean Life Zones 1

2 THE GLOBAL OCEAN Ø vast wilderness, much of it unknown Ø affects cycles of matter on land, influences climate, & weather, provides food Ecology - Ocean Life Zones 2

3 MAJOR OCEAN LIFE ZONES Ø 4 major zones Ø intertidal zone Ø benthic (ocean floor) environment Ø 2 provinces of pelagic (ocean water) environment Ø neritic Ø oceanic (deep-sea) *open-sea zone Ecology - Ocean Life Zones 3

4 Ecology - Ocean Life Zones 4

5 INTERTIDAL ZONE Ø intertidal zone area of shoreline between low & high tides (transition between land & ocean) Ø high levels of light, nutrients, & oxygen biologically productive Ø stressful environment changing & wave action, high & low tides, dry & wet, etc. Ecology - Ocean Life Zones 5

6 Ecology - Ocean Life Zones 6

7 BENTHIC ENVIRONMENT Ø benthic environment ocean floor, which extends from intertidal zone to deep ocean trenches Ø consists of sediments where many bottom - dwelling animals such as worms & clams, burrow Ø productive communities in relatively shallow benthic zones Ø coral reefs Ø seagrass beds Ø kelp forests Ecology - Ocean Life Zones 7

8 MAJOR OCEAN LIFE ZONES: BENTHIC ENVIRONMENT Ø corals small, soft bodied animals similar to jelly-fish & sea anemones Ø eat plankton Ø live in hard cups (or shells) of limestone (calcium carbonate) that they produce using minerals dissolved in ocean water Ecology - Ocean Life Zones 8

9 BENTHIC ENVIRONMENT Ø die, cups remain, & new generation grows on top Ø over thousands of generations, a coral reef forms from accumulated layers of limestone Ø found in warm, shallow seawater Ø poor nutrients but has zooxanthellae (symbiotic algae), favorable temperatures, & year-round sunlight Ø living parts grow in shallow waters where light penetrates Ecology - Ocean Life Zones 9

10 DISTRIBUTION OF CORAL REEFS Ecology - Ocean Life Zones 10

11 BENTHIC ENVIRONMENT Ø most diverse of all marine environments Ø Great Barrier Reef occupies only 0.1 % of ocean s surface but 8% of world s fish species live there Ø benefits: Ø habitat Ø protect coastlines from shoreline erosion Ø seafood, pharmaceuticals, recreation, tourist dollars Ecology - Ocean Life Zones 11

12 BENTHIC ENVIRONMENT Ø sea grasses flowering plants adapted to complete submersion in salty ocean water Ø only in shallow water where they receive enough light for photosynthesis Ø help stabilize sediments reduce erosion Ø provide food & habitats Ø only 5% eaten, rest enters detritus food web & decomposed Ecology - Ocean Life Zones 12

13 BENTHIC ENVIRONMENT Ø kelp brown algae Ø common in Ø cooler temperate marine waters of both northern & southern hemisphere Ø shallow waters along rocky coastlines Ø photosynthetic & primary food producers for kelp forest ecosystems Ecology - Ocean Life Zones 13

14 NERITIC PROVINCE Ø neritic province part of pelagic environment that overlies ocean floor from shoreline to edge of open-sea to a depth of 200 m (650 ft) Ø floaters & swimmers Ø euphotic zone Ø upper layer (surface to 150 m) sufficient light to support photosynthesis Ø large #s of phytoplankton on which zooplankton feed on which nektons (marine organisms that swim freely) feed on, on which carnivorous nekton feed on Ecology - Ocean Life Zones 14

15 OPEN-SEA Ø contains phytoplankton responsible for 80-90% of Earth s photosynthesis Ø contains most free-floating or swimming life forms Ø organisms unable to anchor themselves Ecology - Ocean Life Zones 15

16 OCEANIC PROVINCE (DEEP-SEA) Ø oceanic province - part of pelagic environment that overlies ocean floor at depths >200m (650 ft) Ø 75% of ocean s water Ø deep sea Ø all but surface waters of oceanic province have cold temperatures, high pressure, & an absence of sunlight uniform throughout year Ecology - Ocean Life Zones 16

17 MAJOR OCEAN LIFE ZONES: OCEANIC PROVINCE (DEEP-SEA) Ø fish adapted to darkness & scarcity of food Ø drift or are slow moving reduced bone & muscle mass marine snow organic debris that drifts down into their habitat from upper lighted regions of oceanic province Ø depend on Ecology - Ocean Life Zones 17