Coral Basics
Coral reefs have low biodiversity or high biodiversity?..
High biodiversity
Corals prefer water temperatures around 23-25 degrees Celsius (warm temperatures). True or False?
True
A reef close to and surrounding newer volcanic islands or that borders continental landmasses is called...
Fringing Reef
Theory of formation of coral atolls was first proposed by who?
Charles Darwin
What are some of the causes of reef erosion?
Damage by hurricanes/tropical storms, ocean acidification, exposure to air.
What is ahermatypic coral? What is hermatypic coral?
Ahermatypic coral - Soft corals that do not build reefs, usually inflexible, and breaks down instead of building a reef.
Hermatypic coral - Corals that build reefs (Usually over thousands of years)What is coral's suitable depth in the water? Why?
a.) Within 100m of the surface.
b.) Within 50m of the surface.
c.) Within 20m of the surface.
A reef that is separated by a lagoon from the land mass with which it is associated is called...
Barrier Reef
What happens during the Atoll formation?
a.) The volcanic island sinks down, lagoon starts to form between reef and island, reef becomes barrier reef.
b.) The volcanic island grows and rises
c.) The volcanic island is eaten by the coral larvae
A
What are some of the impacts of reef erosion?
Shores and coastal properties more exposed to damaging effects of waves, destroyed coastal properties.
What are corals?
They are close relatives to sea anemones.
Do corals prefer clear water or turbid water (unclear water)? Why?
Corals need to be in clear water without silt. In clear water, sunlight is able to reach corals that have symbiotic relationship with photosynthetic zooxanthellae.
A coral reef somewhat circular in shape or as a ring around a central lagoon is called...
Atoll
What happens during the atoll formation?
a.) coral larvae eat the volcanic island.
b.) coral larvae grow and colonize the volcanic island, creating a fringing reef around it.
c.) coral larvae eat soup on the volcanic island.
B
Artificial reefs: What are the materials made for constructing artificial reefs?
a.) Concrete
b.) Stones
c.) Large sacks filled w/ sand
d.) Sunken ships
e.) All of the above
D: All of the above!
Explain the process of reef-building by corals.
Coral larvae settle on hard surface and changes into a polyp and divides using asexual reproduction to form the colony. New polyps build skeletons on dead polyps, adding layers of limestone which creates the framework of the reef.
Salinity: Do corals grow better in freshwater or saltwater? Why?
Corals grow better in saltwater. They do not grow well in freshwater because they are not adapted to freshwater.
A small, isolated reef usually located within the lagoon of a barrier reef is called...
Patch Reef
What happens during Atoll formation?
a.) The reef sinks down eventually, forming an atoll.
b.) The reef stays the same.
c.) Volcanic island sinks entirely below water, leaving a ring of coral around central lagoon called an atoll.
Dissipate wave energy, reduce coastal erosion, protect anchored boats.
Coral nutrition? What do corals eat and how?
Reef-building corals have symbiotic zooxanthellae, which provides nutrition to the coral through PHOTOSYNTHESIS. Some corals also eat zooplankton using their tentacles.
a.) Around 5 - 6
b.) Around 8.1 - 8.5
c.) Around 3.5 - 4.5
This is not a type of reef but... What is GEOMORPHOLOGY?
The study of characteristics, origin and development of landforms.
What are some of the evidence in the Theory of Atoll formation? Name at least 2.
Deep drilling shows that as depth of coral increased, age of coral increased.
Corals were found to have grown on underlying volcanic rock.
Fossil corals from base of drilling were dated 50 million years old.
BONUS: Reconstruction of History of Reefs:
What happens to the growth of coral when there is an increase in sea level? What happens when there is a decrease in sea level?Increase in sea level = Increased coral growth
Decrease in sea level = Coral high & dry (decreased coral growth)