1. The Oceans
An overview

3. A quick oceans tour

4. Marine ecosystems Cover 70% of the Earth’s surface.
List as many different marine ecosystems as you can.

5. Marine ecosystems: Estuaries
Estuaries: fresh water from river mixes with ocean
Rich in nutrients
Wetlands form in shallow areas

6. Estuaries Salt marsh Estuaries: very productive ecosystems
What does that mean?
Make lots of biomass
Lots of plant growth/m2
Nurseries for fish, crustaceans

7. Estuaries Coastal Partly enclosed One or more rivers flow into them
Water is brackish—ranges from fresher upstream to saltier where estuary grades into the ocean.

8. Klamath River estuary

9. Estuaries Value Threats Aquatic nurseries Protected harbors
Fishing, other recreation
Habitat for non-aquatic animals, such as bald eagles, shorebirds
Threats
Many near populated areas
May be filled
Pollutants
Sewage
Runoff from rivers

10. Intertidal zone Florida salt marsh Tidal creek running through it
Whole region is tidal, meaning affected by the daily tides

11. Intertidal zone
Means: ``region between the tides’’
Constant change

12. Intertidal Zone

13. Marine ecosystems: mangrove swamps
Coastal areas
Mangrove trees grow partly submerged
Protect coasts from erosion, especially during storms
Tsunami of ‘04

14. Mangrove swamp Roots hold sediment
Habitat for thousands of animal species, such as shrimp
In South America and Southeast Asia, mangrove swamps being cleared for shrimp farms
                                                                                    

15. Coral reefs

16. Coral reefs Made of animals = coral polyps
Limestone skeletons form the reefs
Thousands of species of fish, plants live among the corals  biodiversity hotspot
Need light for photosynthesis, water within temperature and salinity range
BUT: in trouble
People
Warming oceans

17. Coral reefs Individual corals are polyps
Grow together to form large colonies
BUT: grow very slowly, inch or so a year

18. corals ANIMALS Individual = polyp
                                 
ANIMALS
Individual = polyp
Colonies, like reefs, may have been in existence for thousands of years
Most corals contain an algae, zooxanthellae  symbiotic

19. Coral reef distribution

21. For pet stores and for restaurants Philippines
Fishing for tropical fish on coral reefs, using explosives.
For pet stores and for restaurants
Philippines
Also use cyanide
Small amounts stun fish, but continued use can kill coral

22. Continental shelf
aqua color

23. Continental shelves Extension of the continents
Shallow (average about 460 ft)
Significance?
Light reaches much of the shelf
Teaming with life—many important fisheries

24. Littoral zone Nearest the coast
From high water mark to shallow, submerged areas

27. Pelagic – water
Benthic – bottom
Abyssal – deep
Photic – affected by light

28. Marine ecosystems Open ocean: Pelagic Light at surface Fish
Marine mammals
Plankton
Light at surface

29. Marine ecosystems Deep Ocean: benthic zone
Very cold—light doesn’t penetrate
Few if any plants
Bottom feeding organisms
Starfish, anemones, sponges

30. Marine ecosystems Deepest reaches of the ocean: Abyssal zone
Cold
Dark
High pressure
In some places: hydrothermal vents spew superheated water

31. Ocean circulation
Ocean conveyor

33. How they work How we protect them
OCEANS
How they work
How we protect them

34. Oceanography Study of the physical ocean Cover 71% of the Earth
Contains 97 % of its surface water

35. Ocean water 96.5 % H2O by mass Remainder: various salts Temperature:
Warmer near the surface
Deep water (below ~1000 m) is equally cold
Density:
Colder, saltier water is denser = deep water

36. Salinity patterns

37. Ocean currents Water flows horizontally Causes? ocean conveyor
Surface: wind
Deep: density differences – salinity, temperature
ocean conveyor

38. Vertical movements Upwelling
Deep, cold water rises to replace surface waters that flow away
Brings nutrients to surface
Site of rich fisheries

40. Marine ecosystems
Biological diversitydiversity_over_time.pdf

43. Coral reefs form in nutrient poor waters
Nutrients tied up in living things
Nutrients tightly recycled

45. Coral Bleaching
Corals expel the single-celled algae normally living in their tissues
Related to global warming

46. Episodes of coral bleaching

47. Marine ecosystems