Coral Reefs

Types of coral reef

1) Barrier: a coral reef close and running parallel to the shore but separated from it by a channel of deep water. 2) Atoll: They form borders along the shoreline and surrounding islands. When a fringing reef continues to grow upward from a volcanic island that has sunk entirely below sea level, an atoll is formed. Atolls are usually circular or oval in shape, with an open lagoon in the center. 3) Fringing: a coral reef that lies close to the shore. 4) Patch: a small isolated platform of coral.

Common carnivores in a coral reef

1. Nassau grouper 2. Snappers 3. Reef sharks (picture)

Common detritivores (feed on dead remains of plants and animals) in a coral reef

1. Sea cucumber (picture) 2. Spiny Lobster

Common herbivores in a coral reef

1. Sea urchins 2. Parrot fish 3. Wrasses 4. Damselfish (picture)

Producers in a coral reef

1. Seaweed 2. Phytoplankton (picture) 3. Seagrass 4. Zooxanthellae

Hard Corals and 200x anthellae

200x anthellae live inside the tissues of the hard corals in a mutualistic symbiotic relationship. The 200x anthellae gives the coral its color, food and oxygen,

Ecosystem

An area where one or more communities of loving organisms interact with the non living environment to produce a stable system.

Coral Bleaching

Corals have transparent tissues. if a coral becomes stressed due to environmental changes (highwater temperature). In a case like this, the coral expel their zooxanthellae and appearance. This is called Coral Bleaching. Bleached corals are highly vulnerable to disease. If the stress is prolonged so long that the coral are unable to retract zooxanthellae, they may die.

Destructive forces

Forces that destroy the coral reefs. -Harsh waves: breaks coral reefs -Parrot fish: nibbles at the reef -Animals that bore holes: they bore holes that destroy and weaken the structure -Fresh water from rain: it can kill coral -Boat anchors: destroy corals

There are two groups of corals

Hard corals (Hermatypes- reef building coral e.g Brain and Elkhorn coral) Soft corals (Ahermatypes e.g Sea fans-picture- and Sea whips)

How longs does coral reefs take to grow?

Reefs grow very slowly (about 1 cm a year). New coral colonies constantly build on top of dead colonies. But the rate is extremely slow due to competition for zooplankton. Fish excretion helps to build up the reef.

Adaption

The process in which a species becomes better suited to survive in the environment. Adaptions can be physical or behavioral.

Constructive forces

These are natural forces that help enhance the reef. -Sunlight: enhances photosynthesis -Waves: brings nutrients to the reef -Fish excretion: builds the coral reef

How are coral reefs built?

They are built by tiny invertebrates called polyps (these corals belong to the phylum Cnidarian). Coral polyps feed on microscopic algae called zooplankton. Each polyp then secretes an exoskeleton made out of limestone (CaCo3). These exoskeletons join together to form a coral colony which forms a coral reef.

Where are coral reefs formed and what conditions do they need to grow?

They are found in tropical waters that are shallow, warm, clean, clear and sunlit.

Zooxanthellae and Coral polyps

Zooxanthellae is a type of algae. Zooxanthellae gets shelter from the coral. The coral gets food from the zooxanthellae. Zooxanthellae are producers that make their own food and therefore they carry out photosynthesis, The zooxanthellae gives the coral its color and oxygen. They help the coral reef form their exoskeleton. The relationship between the zooxanthellae and polyps are symbiosis or Mutualism.

3. Coloration

a) Camouflage b) Countershading c) Lionfish use bright colors

Some adaptions 1. Body shape

a) Fusiform or Streamlined shape b) Compressed (flattened side to side) c) Depressed (flattened top to bottom) d) Elongated

2. Tail shapes

a) Lunate (moon shape) b) Forked tails c) Rounded tails (grouper - picture) d) Tapered tails (eels)- slow swimmers

4. Mouth location and size

a) small mouths- used for nibbling b) ventral mouths- turned downward (bottom feeding) c) dorsal mouths- upturned mouth (used for eating near the surface) d) anterior mouths- front facing (used for eating in water columns)