Presentation on theme: "Coral Reefs. Introduction Calcium carbonate (CaCO 3 ) anyone?? Limestone is left over when animals grow and die. This carbon containing molecule is the."— Presentation transcript:
Introduction Calcium carbonate (CaCO 3 ) anyone?? Limestone is left over when animals grow and die. This carbon containing molecule is the basis for coral formation. As we will see, coral production exhibits huge impacts on ecosystem diversity and success.
Requirements for Reef Formation High Light Levels High Water Transparency Water Temperatures > 20°C (68°F) Low Nutrient Waters Hard Substrate for Attachment Good water circulation
Coral Types: Hard (Stony, scleractinian, “true”) corals build the reef by extracting calcium carbonate from the ocean water. They create a home in which primary producers can live. They create a diverse 3-D space in which many other organisms can find homes.
What is Coral?? Animal, Vegetable, Mineral? Rem: Coral are actually a special group of cnidarians, the same family as jellyfish!!
Hermatypic vs. Non-Hermatypic Corals Hermatypic Corals (a): Corals that form large colonies called reefs. Ahermatypic Corals (b): Corals that are solitary or form small colonies (often lack zooxanthellae and do not help build reefs). a. brain coral (Diploria) b. Mushroom coral (Fungia)
founder colony Coral larva are called planula, since they don’t like soft sea floors, they often metamorphose into a polyp which establishes a founder colony in a new location. Boulder coral Montastrea cavernosa Medusa’s are a mobile polyp.
Coral remain closely connected. Zooxanthellae, single-celled photosynthetic algae work within the coral to help feed it through photosynthesis. As a result of this symbiotic relationship, many corals don’t need to seek food. This added nutrition also helps corals to build reefs much faster! microscopic view of zooxanthellae)
Mutualism Between Corals and Zooxanthellae Coral Polyp Provides a home for the zooxanthellae. Provides nitrates and phosphates. Gives off CO 2.
To this…. Temperature increases and competition from red algae have killed much of this coral reef.
Coral Reefs Have High Primary Productivity Coral Reef primary production ranges from 1500 to 3700 g of C/m2/yr. This makes Coral Reefs one of the most productive communities on earth! Rapid nutrient cycling between zooxanthellae and corals may be partially responsible for this.
Coral Fights?? Yes! Just like other animals competing for space, coral attack each other if they come into close contact. Usually they just over grow one another, but some actually poison the others out!
Again, we see that real estate is at a premium with these soft corals. Soft corals are fast growers, making them excellent competetors.
Harmony? Not really, most animals on reefs compete daily for everything, from food to mating opportunities.