The document summarizes several marine ecosystems and the organisms found within them. It describes plankton as organisms that cannot swim against ocean currents, including photosynthetic phytoplankton like diatoms, dinoflagellates, and cyanobacteria, as well as zooplankton that eat other organisms. It also discusses nekton that can swim against currents. Several ecosystems are outlined, such as the rocky intertidal zone, estuaries, coral reefs, the open ocean, deep sea hydrothermal vents, and the challenges of life in each.

1. Marine Ecology

2. Ocean zones

3. Benthic (living on the bottom – crawling, burrowing or sessile) OR Pelagic (living in the water – swimming or drifting) Plankton (cannot swim against ocean currents) Nekton (can swim against currents) Marine organisms

4. Organisms that cannot swim against currents Some are photosynthetic (phytoplankton) Some eat other organisms (zooplankton) Some do both! Plankton

5. Photosynthetic… create most of Earth’s oxygen! Must stay in photic zone to survive Common name: algae Several types: Diatoms Dinoflagellates Cyanobacteria Phytoplankton

6. Diatoms Have intricate glass shells Form chains to increase surface area

7. Dinoflagellates Have 2 flagella – one wraps around the middle, the other is at the tip Cause red tide!

8. Cyanobacteria Stromatolites (clumps of cyanobacteria) … some several million years old! 

9. Eat other organisms Can be very tiny or quite large Includes many phyla, from jellyfish to crustaceans Also includes larvae of some benthic organisms Zooplankton

10. Copepods Very small – most around 1mm

11. krill

12. Ctenophores (comb jellies)

13. Jellyfish

14. Larvae of benthic organisms Crab Sea Cucumber Sea urchin Snail Worm Starfish

15. Other zooplankton

16. Nekton

17. Watch Seasonal Seas Playlist

18. Rocky intertidal Estuary Coral reef Open ocean Deep sea Hydrothermal vent Marine ecosystems

19. A very challenging environment! Fluctuates between being underwater and being exposed to the sun and wind Highly variable temperatures and salinity Constantly battered by waves Rocky intertidal ecosystem

20. How do organisms survive? Seal in moisture Adhere to rocks Have the ability to pull the body into a protective covering Rocky intertidal survival

21. Rocky intertidal organisms

22. Estuary ecosystem Where rivers meet the sea! Mixing of ocean and fresh water… highly variable salinity Tidal variation High nutrient levels and sediment load… create very fertile farmland!

23. Estuary ecosystem

24. Usually includes either: Salt marsh (temperate zones) Mangrove forest (tropics) Estuary ecosystem

25. Located in warm, clear shallow water Very abundant life Many brightly colored organisms Multiple phyla represented (sponges, cnidarians, molluscs, arthropods, echinoderms, vertebrates – fish) Coral reef ecosystem

26. Coral reef organisms

27. Same phylum as anemones and jellyfish Deposit calcium carbonate skeleton Colonies of clones Contain photosynthetic algae - zooxanthellae What IS coral?

28. What IS coral?

29. Unicellular photosynthetic organisms live inside corals Photosynthesis provides sugar for coral Photosynthetic pigments give corals their color Zooxanthellae

30. Zooxanthellae abandon corals when temperatures get too high… even only 1 ° Coral bleaching

31. Watch Coral Seas Playlist

32. Very deep photic zone – not much sediment suspended in water, not much plankton Average depth 3800m Largest ecosystem on the planet! Dominated by fish, sharks and whales Open ocean

33. Open ocean organisms

34. Watch Open Ocean Playlist

35. Below the photic zone (1000m in open ocean) Constant darkness Cold (usually around 1-2 °C) Very high pressure! (see cups) Organisms are few and far between Deep ocean

36. Red, black or clear bodies Bioluminescence to see in the darkness or attract prey Huge mouths to eat food in any available form Permanent mating arrangements… Deep ocean adaptations

37. Deep ocean organisms Show Blue Planet: “The Deep” chapters 1-10

38. Watch The Deep Playlist

39. Marine Ecology show The Deep

40. Deep ocean “springs” associated with cracks in Earth’s crust Whole communities based on sulfides, not sunlight Discovered in 1977 Hydrothermal vents

41. How do hydrothermal vents work?

42. Hot, mineral-rich water steams out of Earth’s crust Special chemosynthetic bacteria metabolize hydrogen sulfide into sugars the same way photosynthetic organisms use sunlight Vent tube worms have these chemosynthetic bacteria living inside them (like zooxanthellae in coral) How life works at hydrothermal vents

43. Hydrothermal vent organisms Show chapters 11-12 of Blue Planet: “The Deep”

44. Other ocean ecosystems Seagrass beds Polar ice communities