Transcript corals.mangroves

Coral reefs
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
Global distribution of coral reefs
(Osborn Fig. 11.10)
Higher coral generic richness in Indo-Pacific
(and accompanying fish diversity)
Highest diversity of corals in Indo-Australian archipelago
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)
Types of reefs: fringe, barrier, atolls
Atolls “final stage of tropical island
development” (Charles Darwin 1942,
Structure and Development of Coral Reefs”)
Reef structure
Sandy flats dominated by Parchment
worms (Chaetopterus spp.)
Types of reef building corals
Brain corals
With extended polyps
Coral anatomy
(Osborn Fig. 11.2)
Coral Anatomy: mutualism between
corals and Zooxanthellae algae
Growth rings in corals
Mutualism between clown fish
and sea anemone
• Clown fish is
coated with the
same mucous as
anemone.
• Fish brings food.
• Anemone protect
fish.
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?
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
Florida geology: 140 yr old lime stone,
14,000-9,000 yr old corals to make the Keys
Florida Keys
Oolite: limestone made in coral reefs
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.
Fresh water lens under coral
island and the Everglades
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).
Seagrasses of W. Australia
Posidonia seagrass meadow in W. Australia
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.
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.
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
Mangrove biogeography ocean
current and continental movement
(Osborn Fig. 10.2)
Mangrove species in Indonesia (FAO
World Atlas of Mangroves)
Acanthus ebracteatus
Acanthus ilicifolius
Acrostichum aureum
Acrostichum speciosum
Aegialitis annulata
Aegiceras corniculatum
Aegiceras floridum
Avicennia alba
Avicennia marina
Avicennia officinalis
Avicennia rumphiana
Bruguiera cylindrica
Bruguiera exaristata
Bruguiera gymnorrhiza
Bruguiera hainesii
Bruguiera parviflora
Bruguiera sexangula
Camptostemon philippinensis
Camptostemon schultzii
Ceriops decandra
Ceriops tagal
Excoecaria agallocha
Excoecaria indica
Heritiera globosa
Heritiera littoralis
Kandelia candel
Lumnitzera littorea
Lumnitzera racemosa
Nypa fruticans
Osbornia octodonta
Pemphis acidula
Rhizophora apiculata
Rhizophora mucronata
Rhizophora stylosa
Rhizophora x lamarckii
Scyphiphora hyrophyllacea
Sonneratia alba
Sonneratia caseolaris
Sonneratia ovata
Sonneratia x gulngai
Sonneratia x urama
Xylocarpus granatum
Xylocarpus mekongensis
Taller & species rich mangroves
in Australia
Rhizophora & Soneratia in Darwin Harbor, AU
Faunal zonation in mangrove and
salt flat zones: Australia
(Osborn Fig. 10.5)
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)
Mangroves in Florida
Red mangrove (Rhizophora mangle)
Black mangrove (Avicenia germinans)
Mangroves in Florida
White mangrove (Laguncularia racemosa)
Acrostichum spp. (mangrove ferns)
Mangrove zonation: Florida
Salt excluder
Salt excreters
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
Red mangrove: vivipary
Not all mangroves have (true) vivipary.
Red mangroves
Black mangrove
(cryptovivipary)
Vivipary is not just for mangroves…
Zonation mechanisms
• Salt tolerance (frequency and duration of
inundation, maximum salt concentration)
• Ocean current’s force (especially during
storms)
• Competition
• Seedling establishment
Mangroves in
Mexico
Destruction of mangroves for shrimp farming