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Coral reefs

Coral reefs. Coral reefs. One of the most biological diverse and productive ecosystem Found in warm, clear and shallow tropical oceans On CaCO 3 substrate deposited by reef building corals (50% of all Ca deposit in the sea) and other calcified organisms. Provide shelters and food to fish .

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Coral reefs

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  1. Coral reefs

  2. Coral reefs • One of the most biological diverse and productive ecosystem • Found in warm, clear and shallow tropical oceans • On CaCO3 substrate deposited by reef building corals (50% of all Ca deposit in the sea) and other calcified organisms. • Provide shelters and food to fish

  3. Global distribution of coral reefs(Osborn Fig. 11.10)

  4. Higher coral generic richness in Indo-Pacific (and accompanying fish diversity)

  5. Highest diversity of corals in Indo-Australian archipelago

  6. Figure 4. Analysis of factors influencing biodiversity of coral reefs, illustrated by the percent variation in taxonomic composition of fish and coral assemblages explained by habitat area, longitude, and latitude. (Bellwood & Hugh 2001, Science 292: 1532-1535)

  7. Types of reefs: fringe, barrier, atolls Atolls “final stage of tropical island development” (Charles Darwin 1942, Structure and Development of Coral Reefs”)

  8. Reef structure

  9. Sandy flats dominated by Parchment worms (Chaetopterus spp.)

  10. Types of reef building corals

  11. Brain corals With extended polyps

  12. Coral anatomy (Osborn Fig. 11.2)

  13. Coral Anatomy: mutualism between corals and Zooxanthellae algae

  14. Growth rings in corals

  15. Mutualism between clown fish and sea anemone • Clown fish is coated with the same mucous as anemone. • Fish brings food. • Anemone protect fish.

  16. Why is diversity so high in coral reefs and rain forest? • On nutrient poor water • High level of mutualism and symbiosis • High productivity and high rates of nutrient cycling • Finely divided niches • Control by herbivores and competitions?

  17. Limestone outcrops in S. Florida: >10,000 yr old land rich in endemic Ca-loving herbaceous plants • Miami rock ridge & upper keys: Oolitic limestone, precipitated in sallow sea supersaturated with CaCO3 • Lower keys: coral origin

  18. Florida geology: 140 yr old lime stone, 14,000-9,000 yr old corals to make the Keys

  19. Florida Keys

  20. Oolite: limestone made in coral reefs

  21. Florida marsh distribution • North: sink hole origin and untable. • Kissimmee river basin: where the land sagged slightly from dissolution of underlying limestone. • Lake Okeechobee: water dammed by the sedimentation in the southern rim. • Northern Everglades: river of grass, following the gradual elevational gradient to SW. • Southern Everglades: freshwater lens pushed up by the saltwater underneath.

  22. Fresh water lens under coral island and the Everglades

  23. Tropical estuary: • Sea grass beds • Mangroves, mudflat, marshes • Higher species diversity of mangroves and seagrass species in Asia-Australia (eastern group) than in America (western group).

  24. Seagrasses of W. Australia Posidonia seagrass meadow in W. Australia

  25. Seagrasses: flowering plants that returned to the sea • Origin: 100 m.y. BP., in Tethys Sea • 2 families: Potamogetonaceae & Hydrocharitaceae (NOT in grass family) • 58 species, 12 genera, mostly in tropical Asia-Australia. • Found mostly in shallow coastal water, salt marshes, and estuary.

  26. Dinosaurs dominant, mammals evolving as subdominant.Angiosperm is rapidly increasing dominance, replacing ferns and gymnosperms. But, no tropical rain forest dominated by tall angiosperm trees yet.

  27. Mangroves • 75% of tropical coast lines (water temp above 24 C) • 40 spp. in Eastern group, 8 spp in Western group. Convergent evolution in different families. • 3 spp. in Florida (red, black, and white) • Highly productive • Important habitat for costal animals

  28. Mangrove biogeography ocean current and continental movement (Osborn Fig. 10.2)

  29. Mangrove species in Indonesia (FAO World Atlas of Mangroves) Acanthus ebracteatus Acanthus ilicifolius Acrostichumaureum Acrostichumspeciosum Aegialitisannulata Aegicerascorniculatum Aegicerasfloridum Avicennia alba Avicennia marina Avicenniaofficinalis Avicenniarumphiana Bruguieracylindrica Bruguieraexaristata Bruguieragymnorrhiza Bruguierahainesii Bruguieraparviflora Bruguierasexangula Camptostemonphilippinensis Camptostemonschultzii Ceriopsdecandra Ceriopstagal Excoecariaagallocha Excoecariaindica Heritieraglobosa Heritieralittoralis Kandeliacandel Lumnitzeralittorea Lumnitzeraracemosa Nypafruticans Osborniaoctodonta Pemphisacidula Rhizophoraapiculata Rhizophoramucronata Rhizophorastylosa Rhizophoraxlamarckii Scyphiphorahyrophyllacea Sonneratia alba Sonneratiacaseolaris Sonneratiaovata Sonneratiaxgulngai Sonneratiaxurama Xylocarpusgranatum Xylocarpusmekongensis

  30. Taller & species rich mangroves in Australia Rhizophora & Soneratia in Darwin Harbor, AU

  31. Faunal zonation in mangrove and salt flat zones: Australia (Osborn Fig. 10.5)

  32. New World mangroves Red = Rhizophora mangle (Rhizophoraceae) Black = Avicinia germinans (Rhizophoraceae) White = Laguncularia racemosa (Combretaceae) (http://www.floridaoceanographic.org/environ/mangrove1.htm) Often accompanied by: Conocarpus electus (Combretaceae) Pelliciera rhizophorae (Pellicieraceae) Acrostricum spp. (ferns)

  33. Mangroves in Florida Red mangrove (Rhizophora mangle) Black mangrove (Avicenia germinans)

  34. Mangroves in Florida White mangrove (Laguncularia racemosa) Acrostichum spp. (mangrove ferns)

  35. Mangrove zonation: Florida Salt excluder Salt excreters

  36. Physiological adaptation of mangroves • Salt management: • exclude (Rhisophora) • excrete (from salt glands in leaves, Avicinnia, Laguncularia) • tolerate (accumulate in vacuoles – not in FL) • Thick cuticles on leaves to tolerate desiccation • High tannin to prevent herbivory • Pneumatophores and lenticels to send oxygen to roots

  37. Red mangrove: vivipary

  38. Not all mangroves have (true) vivipary. Black mangrove (cryptovivipary) Red mangroves

  39. Vivipary is not just for mangroves…

  40. Zonation mechanisms • Salt tolerance (frequency and duration of inundation, maximum salt concentration) • Ocean current’s force (especially during storms) • Competition • Seedling establishment

  41. Mangroves in Mexico Destruction of mangroves for shrimp farming

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