1. Marine Ecology, May 19, 2008 Epipelagic/Antarctic Marine Ecosystem, Part 1

2. The epipelagic zone Epipelagic  Upper pelagic, within photic zone Neritic  Waters on the continental shelves Oceanic  Waters beyond the shelf break

3. Epipelagic food web(simplified)

4. “Classic” food chain vs. microbial loop

5. Phytoplankton types 1 Free-floating photosynthetic Bacteria and Archaea Cyanobacteria Photosynthetic Archaea

6. Phytoplankton types 2 Photosynthetic Protista Diatoms: have silicaceous “frustules”; many form chains Dinoflagellates have two flagella Prymnesiophytes (i.e. Phaeocsytis) exist as single cells or colonies Cryptophytes are single and small

7. Global primary productivity: marine

8. Factors affecting phytoplankton growth Light Nutrients Location of the pycnocline Temperature Role of ice in polar regions

9. Light levels as a function of latitude

10. Nutrients (inorganic) Nutrient sources  Upwelling: coastal and equatorial; Edges of islands and reefs  Deep mixing by winter storms Examples: Key in Pacific Northwest, Antarctica  Runoff from land Example: In Antarctica, bird and seal colonies produce nutrient-rich waste

11. Nutrients Nutrient sinks  Nutrients consumed by primary producers  Uneaten phytoplankton, consumers and their fecal material sink out of photic zone

12. Which is limiting, nutrients or light? (Very simplified…) In Antarctic,  Light-limited through much of year  Possibly nutrient- limited later in the season… Affects phytoplankton community composition

13. Pycnocline: location and stability Shallow, stable pycnocline promotes phytoplankton growth

14. Pycnocline: location and stability

15. Temperate ocean (i.e. Oregon) *Shallow pycnocline: late spring through summer. Causes?

16. Polar ocean (i.e. Antarctica) *This shows open water. What about ice- associated areas?

17. Ice! Role in pycnocline set-up and stability Role in “seeding” ice edge blooms

19. Seasonal variation in ice cover (Parkinson et al.,1998)

20. Variability in phytoplankton community composition Both spatial and temporal variations.  Why? Varying light levels Varying nutrients Presence in water column or ice  Example: Phaeocystis vs. diatoms in Antarctic phytoplankton blooms

21. Zooplankton: overview Key crustacean zooplankters  Copepods

22. Zooplankton: overview Key crustacean zooplankters  Krill!

23. Zooplankton: overview Gelatinous zooplankters Salps (above) and larvaceans (below) both feed on picoplankton and nanoplankton Ctenophores are predators of other zooplankters

24. Beware of Beröe! Feeds on other ctenophores; appears to reduce their negative impacts!

25. Antarctic marine food web (simplified)

27. Focus on krill! Basic anatomical features Feeding behavior Food selectivity (briefly)  Primarily herbivores; feed preferentially on diatoms compared to Phaeocystis!  Winter omnivory? Schooling Life History

28. Life history basics Nauplius

29. Furcilia and juveniles (mostly) feeding beneath the ice

30. Declining krill? Or not…? (Angus Atkinson, 2004, Science)

31. Focus: Antarctic penguins Gentoo penguins (Photo: B. Grunewald) Adelie penguins (Photo: K. Haberman) Chinstrap penguin (Photo: Shir Goldberg

32. Adaptations for swimming, diving, cold water & snow Solid bones Hindlimb  Rearward rotation  Webbed feet  Claws Forelimbs  Modified as paddles Air sacs: reduced Other…

34. Shift in penguin species on the Antarctic Peninsula

35. Black-browed albatross Feeds primarily on krill! Black-browed albatross Photo: K. Haberman

36. Feeds primarily on krill “Gack” defense by young Southern giant petrel Photo: K. Haberman

37. Wilson’s storm petrel “Jesus birds”: feed on near-surface zooplankton (smaller krill species, copepods, amphipods) Wilson’s storm petrel Photo: K. Haberman

38. Blue-eyed shag (cormorants) Feed on fish and squid; deep divers Have heavy bones like penguins Blue-eyed shag Photos: K. Haberman

39. Kelp gulls Limpet eaters! Kelp gulls Photo: K Haberman

40. Order Pinnipedia, Family Phocidae Crabeater seal Photo: Karen Haberman

41. Crabeater seal skull showing krill eater teeth!

42. Elephant seals

43. Order Pinnipedia, Family Phocidae Leopard seal Photo: Karen Haberman

44. Order Pinnipedia, Family Phocidae Weddell seal Photo: Karen Haberman

45. Order Pinnipedia, Family Otariidae Southern fur seal (related to sea lions) Photo: Karen Haberman

46. Order Cetacea; Suborder Mysticeti Humpback Whale Photo: K. Haberman

47. Order Cetacea; Suborder Mysticeti Minke Whale Photo: Project Atlantis

48. Order Cetacea; Suborder Mysticeti Blue Whale Photo: Project Atlantis

49. Order Cetacea; Suborder Odontoceti Family Delphinidae Orca Photo: NOAA