1. Coral Reefs
Outcome: To understand where coral reefs are distributed, examine the symbiotic relationships within coral reefs, compare/contrast the three reef types, and understand the danger corals face

2. Tropical Paradise
In the waters in tropical paradises (bottom left) what do you notice that would be different from Ocean City (bottom right)?

3. Coral Reef Distribution
Coral waters are relatively nutrient poor giving them a clear blue coloration.
How is the diversity of the coral supported in such a nutrient poor community?
Zooxanthellae!!
(ZOH-oh-zan-thel-ee)

4. Zooxanthellae
Zooxanthellae are dinoflagellates the make up a large part of the reef system.
Zooxanthellae are symbionts for jellyfish, corals, and molluscs.
Zooxanthellae are photosynthetic algae providing food (sugar), O2, and lipids (fats) for their host organism and the host (coral) provides CO2, H2O, and shelter for them.

5. Coral Reefs
Coral reefs are massive structures made of calcium carbonate secreted by corals living within the reef.
Although thousands of species inhabit coral reefs, only a fraction produce the limestone that builds the reef. The most important reef-building organisms are the corals.

6. What is Coral?
Coral is often mistaken for a rock or a plant, but these fragile animals are called coral polyps.
When people say coral, they are referring to these little animals and the skeletons they leave behind after they die.

7. Coral Polyp
A coral polyp is an invertebrate that ranges in size from the size of a pinhead up to a foot in diameter.
Coral polyps are cousins to anemones and jellyfish

8. Coral Reefs
A polyp has a saclike body and an opening, or mouth, encircled by stinging tentacles called nematocysts.
Coral polyps are usually nocturnal hunters and only have their paralyzing tentacles out at night.
This is because the zooxanthellae do NOT photosynthesize at night

9. Coral Polyp Stomach and digestive filaments make up most of
the polyps structure
Polyps take in and expel
waste from their mouth
The coensarc connects
the polyps together to form
a colonial organism

10. Coral Polyps

11. Coral Colony
One coral branch or mound is covered by thousands of coral polyps called a coral colony.
Thus, each coral branch or mound is one colony of coral polyps.

12. Formation of Coral Colonies
Larva attaches to hard surface
Larva develops in to a polyp
Polyp reproduces asexually by budding
The shape is genetically determined
New polyps continue to bud

13. Formation of Coral Reefs
There are three types of coral reefs:
Fringing reefs: project seaward directly
from the shore (10,000 years)
Barrier reefs: move outward from shore
to create a lagoon separation (100,000 years)
Atoll: the island/volcano complete
submerges and a lagoon center is left
(30,000,000 years)

14. Fringing Reef

15. Barrier Reef

16. Atoll

17. Zooxanthellae in the coral tissue Bleached coral:
Healthy coral:
Zooxanthellae in the coral tissue
Bleached coral:
Zooxanthellae expelled from tissue
Dead coral:
Skeleton covered in filamentous algae

18. Major Bleaching Events

19. Danger Facing Coral Reefs
Increase water temperatures due to global warming cause coral to release their zooxanthellae and coral bleaching occurs.
Hurricanes/typhoons/cyclones cause massive damage by toppling coral formations and removing them from the reef.
Human impacts such as coastal development, increased CO2 production, increase sedimentation and encourage overfishing.
Coral diseases such as black band disease and white pox can also occur when bacteria attack the coral.

20. Bleached Coral

21. Black band and White Pox

22. Coral Reefs In Decline Day 16
Drill: As you watch the video write down biotic and abiotic factors that affect coral reefs.
Outcome:
Compare and contrast the biotic and abiotic factors of a coral reef under stress and a coral reef that is not under stress.
Hypothesize reasons why coral reefs may or may not be under stress.

23. Coral Reefs In Decline
Your job today will be to form groups (2 to 3) and find corals in our oceans that are stressed and not stress and compare them
You will use Google Earth to help find them and identify why they may be stressed
You must choose a reef from the list provided, so let’s take a look at what I mean!

24. Biotic and Abiotic Factors
Coral is affected by biotic and abiotic factors daily
Some factors can lead to a decline in the population due to coral bleaching.
In groups you will go to
You will click on
Google Earth will open
You will choose two reefs from this list:
One reef should be stress free
One reef should have stress and be in danger of bleaching
You will try to hypothesis what biotic and abiotic factors are different between the two reefs that would cause one to bleach and one to be normal
All info will be placed on the back of the map sheet

25. Reef Life Coral reefs are the rain forest of the waters.
The diversity found in coral reefs is what makes them so fascinating and important to protect
Molluscs, Echinoderms and Arthropods

26. Echinoderms Sea urchins, sea stars, brittle stars, and sea cucumbers
Can be both sessile, brittle stars, and mobile, sea urchins and sea stars
Some sea stars eat the reefs, taking down 1/3 since 1957

27. Molluscs Clams, sea snails (nudibranchs), octopi, and squid
Feed on sponges, anemones, and jellyfish
Giant clams, 3 feet, filter feed but also have zooxanthellae

31. Crustaceans Shrimps, crabs, lobsters and horseshoe crabs
Symbiont because they use coral as a cover to attack prey
Mantis shrimp’s strike is so powerful it can cut another shrimp in half