Pg. 76 RTW: What is an advantage & disadvantage of clumped dispersion? Monday, January 9th Pg. 76 RTW: What is an advantage & disadvantage of clumped dispersion? Objective: Discuss the characteristics of populations, such as number of individuals, age structure, density, and pattern of distribution. Agenda: Turtle Survivor questions on pg. 80 Homework: Test Friday (1/13)

Tuesday, January 10th Pg. 76 RTW: What type of survivorship curve has a high infant mortality (Type 1, 2, or 3)? What type of organisms have these? Objective: Learn what makes up a coral reef and what types of factors affect it’s productivity. Agenda: Have Turtle Questions (pg. 80) out to be graded Coral Notes pg. 81 Homework: Test Friday (1/13)

The Coral Reef Kingdom: Animalia Phylum: Cnidaria (also includes jellyfish and sea anemones) The largest number of coral reef species are found in the Indo-Pacific

Make-Up Each coral polyp (or animal) occupies a little calcium carbonate (CaCO3) cups (this is limestone), called corallites. Around the mouth are tentacles that have many stinging cells called nematocysts that it uses to capture food (normally plankton).

2 Types of Coral Polyps Hermatypic – produces reefs; have a symbiotic bacteria called zooxanthallae that live in their tissues; found only in the tropics; colonial Ahermatypic – do not form reefs; do not have zooxanthallae; solitary

Reproduction Asexual Sexual Budding Fragmentation of skeletal pieces Males release sperm into water and females release eggs. These come together and form a planula larvae This larvae settles and makes a new polyp.

Abiotic Limiting Factors Light - (they must be able to get rid of sediment that can cover them) Salinity - (hurricanes can throw this off) Temperature - (most important; around 20oC)

Nutrition Carnivorous – use nematocysts to capture and eat plankton. HOWEVER, there is only enough plankton to make up 5-10% of their food needs. The bacteria, zooxanthallae, living in the polyps, are photosynthetic. They make their own food and 90-95% of the food for the coral polyp.

Coralline algae Red algae that are extremely important in constructing and maintaining reefs. Secretes CaCO3 in a thin layer over the reef that cements all the pieces together Helps the reef resist wave destruction. Too much = suffocate the coral polyps.

Coral Reefs coral reefs are the most taxonomically diverse of all ecosystems on Earth while diverse, they are also fragile the conditions coral requires for life are narrow and specific: clear water dinoflagellates coexisting in the polyps need light for photosynthesis. water that’s in moderate motion this prevents sediments from accumulating on polyps Coastal Ecosystems >

Coral Reefs water that is relatively free of nutrients. lack of nutrients actually protect coral from other organisms with too many nutrients, algae grows displacing coral and plankton grows reducing water clarity and the amount of sunlight when a body of water is choked by plant life it is called eutrophication Coastal Ecosystems >

Coral Reefs Threats to coral reefs include: eutrophication levels have been rising over the last several decades thermal stress coastal dredging and construction cause sediment to accumulate on the polyps faster than water motion can remove it coral diseases Coastal Ecosystems

Competition on the Reef Corals compete for LIGHT! The upright, branched, faster growing corals extend up and shut out light from the slower growing, encrusting corals = Exploitative Competition BUT, the slow growing corals must be more aggressive in order for them to grow. They release digestive filaments from their “stomachs”, which kills nearby competing corals = Interference Competition

Coral Bleaching Corals bleach = expel the zooxanthellae. They become white. If the bacteria is gone for too long, the coral polyp will die. The cause of bleaching is unclear, but is probably b/c of stress, usually due to increased temperature. Occurs mostly to corals in shallow-water. Thought to be an early sign of global warming.

Pg. 76 RTW: What are the threats to corals? Wednesday, January 11th Pg. 76 RTW: What are the threats to corals? Objective: Prepare for Unit 8.1 Test. Agenda: Review Homework: Test Friday (1/13)

Pg. 76 RTW: Create one test question for your neighbor Thursday, January 12th Pg. 76 RTW: Create one test question for your neighbor Objective: Prepare for Unit 8.1 Test. Agenda: Review Homework: Test Friday (1/13)

Grab your clicker, bags upfront, NO CELLPHONES Friday, January 13th Grab your clicker, bags upfront, NO CELLPHONES Objective: I will be able to ace the 8.1 test. Agenda: Test Homework: None 