Coral Reefs Flashcards
Bioherm
Massive structures produced by biological activity
What is a coral?
2500 species Solitary or colonial Reef builders and not No medusa stage Subdivided GVC
Coral phylogeny
Phy Cnidaria
Subphy Anthozoa
SubCl Hexacorallia
Or Scleractina
Coral anatomy
Tentacles, oral disk, mouth, septa = mesenteries
Coral anatomy: corallum
The whole structure of coral
Coral anatomy: Coralite
Places for individual polyps to be
Coral anatomy: Theca
Cup for polyp to sit in
Basal plate
Where is set and secrete calcium carbonate
Columella
Supports on the side
Dr. Coal: calcium carbonate
Calcium carbonate closely mirrors what is seen and bones. Can be chemically treated to become hydroxyapatite. Can be used in eye transplants to allow movement from blood vessel attachment.
Oasis in the desert
Reefs typically found in tropics. Open ocean has low amounts of carbon
Zooxanthellae
Single – celled photosynthetic organisms with symbiotic relationship with coral. Live in the tissue and are critical for reef building.
Zooxanthellae relationships
Symbiodinium
Mutualism
Benefits to Zooxanthellae
Predator avoidance. Excreted nutrients. CO2 production. Access to light.
Benefits to coral
Removal of dissolved excretory products. Provide oxygen.
Provide carbohydrates.
Aid in lipid synthesis.
Enhance coral calcification
Calcium equation
Zooxanthellae enable corals to form calcium carbonate skeletons by rapid removal of CO2
Coral Types
Massive
Branching
Flat, Table
Reef Profile
The shallower parts of the reef offer different habitats according to the amount of wave energy and light they receive. Reefs of flat areas to capture light and food. Barriers block waves to keep see any beaches.
Fore Reef Structures: Spurs and Grooves
Protect land on back side of groove.
Corals broken up to allow for water diversion so not to break coral.
Spurs
Living coral
Grooves
Mostly sand
Location of reefs
Found in warm tropical areas
Factors limiting distribution of reefs
Temperature: hotter than 20 C Depth: optimal 25 for light Salinity: optimal 32-35 ppt Sedimentation: limited Wave action: moderate Submergence: limited
Compare Atlantic and Pacific Reefs
Pacific reefs much more diverse and populated than Atlantic
Classification of Reefs
Fringing reefs
Barrier Reefs
Atolls
Fringing reefs
Occupy continental or island margins without deep lagoon or channel between mainland and reef crest; most reefs
Barrier Reefs
Occupy continental margins but are separated from a land by broad deep channel or lagoon; further off shore
Atolls
Are oceanic, non-continental with a circular reef crest enclosing a central shallow lagoon; island made of limestone
Biological factor: coral competition
Exploitative and interference.
Pavona (massive) vs. Pocillopora (branching)
Pocillopora wins
Biological factor: Coral versus Algal competition
Damaged coral, limited space, Algal wants to occupy space; don’t allow coral to recover
Biological factor: predation
Corallivores
Eat corals
Small hurricanes can help thermally distressed; big hurricanes can destroy
Parrot fish and sturgeon fish poop sand to cement corals together
Physiological factor: coral bleaching
Corals eliminating zooxanthellae when they get stressed from warmer temperatures and lower pHs
Physiological factor: acidification
Oceans are carbon sinks which lead to acidification.
Why get rid zooxanthellae?
Get rid of some hoping those that can live through hotter temps and lower pH will repopulate to evolve
