Coral Reef Ecosystem Flashcards
Where do reefs grow?
- thrive in water that is clean, clear, sunlit, shallow with warm temperatures.
What is a Coral Reef?
Coral is an animal with a unique polyp structure that builds a hard, rock-like like skeletal base, and holds symbiotic algae called zooxanthellae.
how are corals classified?
Coral is an invertebrate marine organism of the class Anthozoa (phylum Cnidaria).
What are the two groups of corals?
hermatypes or hard corals that build reefs and ahermatypes or soft corals.
Describe the corals body
The body of a coral animal is called the polyp, a hollow sac-like structure, with a mouth surrounded by tentacles, and inside the body is a stomach.
What does the tentacles of the coral reefs contain ?
The sticky tentacles contain stinging structures, called nematocysts, that enable the polyp to gather food usually at night-time by paralyzing its passing prey. The tentacles then deposit the food in the mouth where it passes down into the stomach.
What does the stomach contain?
Within the stomach are long, tubular filaments that the polyp extends to defend itself from attack by other encroaching coral.
What does the hard corals extract ?
The polyps of the hard corals extract calcium carbonate from the sea water and use it to build a hard-external limestone skeleton beneath and around their base which secures the fragile polyp to a surface and serves as its protection.
Who does coral have a symbolic relationship with?
Within the tissue of the polyp live many microscopic algae or plant cells called zooxanthellae. These algal cells have a symbiotic relationship (mutualism- association between organisms of two different species in which each benefits.) with the coral.
How does corals benefit zooxanthellae?
Corals provide zooxanthellae with protection, a place to live, nutrients and carbon dioxide, a by-product of respiration, which is vital for photosynthesis.
Zooxanthellae photosynthesize (make their own food) using sunlight and the coral’s waste products to produce oxygen and sugars.
How does zooxanthellae benefit corals?
The oxygen is used by the polyp for respiration and the sugar are used for energy to build its limestone skeleton. The coral’s colour comes from the colour of the zooxanthellae living in the polyp’s tissue.
What happens if coral is in the absence of zooxanthellae?
If the polyps go for too long without zooxanthellae, coral bleaching can result in the coral’s death.
What is Coral Bleaching?
When the temperature of the water is too warm, corals will expel the algae living in their tissues causing the coral to turn completely white.
How does coral reproduce asexually ?
Polyps live in close association with each other forming a colony (a cluster of coral polyps connected) that act as a single organism. The colony is produced by asexual reproduction by a process called budding.
How does corals reproduce sexually?
Polyps also reproduce sexually, they release sperm and eggs into the water, which join to form the planula which forms new reefs.
What are Hard Corals? ( describe )
Reef-building corals, which secrete a hard-external limestone skeleton. They have tentacles in multiples of six and can be found either individually or in colonies. These hard-coral colonies exhibit three basic growth forms: branching, massive, and plate.
Examples of hard corals ?
Common types of hard corals are Brain Coral, Staghorn Coral, and Elkhorn Coral.
What are soft corals adaptions ?
Soft corals also grow in colonies on the reef, but do not build reefs. They are supported by tiny spines on their skeleton. Their soft skeleton allows them to bend, wave, sway, and spread out in the water. Some of the soft corals produce toxic compounds that make them unappetizing to predators.
Soft corals secrete a flexible or soft skeleton. They have eight tentacl
Examples of Soft corals?
Common types of soft corals are sea fan, and sea whip coral.
Where does soft corals thrive ?
Soft corals thrive in strong currents where they have access to lots of plankton. They also grow well in a strong rumend corals cannot grow, such as dark caves and overhangs.
BIODIVERSITY, FOOD PRODUCTION, SHELTER
Benefits of Coral Reefs
Biodiversity: spawning (release or deposit eggs), nursery, breeding, and feeding grounds for numerous organisms.
Food Production: provide a large feeding area for a large variety of organisms, and they exchange energy and nutrients with other marine ecosystems.
Shelter: provide shelter and a habitat for thousands of species of organisms.
Storm Protection, Economy, Medicine
Benefits of Coral Reefs?
Storm Protection: coral reefs break waves during storms and hurricanes, protecting shorelines from erosion, flooding, and keeping beaches and coastal communities intact.
Economy: provide a huge source of income and millions of jobs around the world. Reef dependent fisheries include subsistence, commercial, recreational, and ornamental. Tourism is an economic mainstay for many countries with coral reefs, as people come to dive, snorkel, boat, and fish.
Medicine: Treatments for cancer, AIDS, infection, arthritis asthma, herpes, ond even broken bones are being discovered in coral reef ecosystems around the world.
What are the threats to Coral Reefs
Natural Threats to coral reefs include:
- hurricanes and storms
- sea-level changes (ex: decreased sea level);
- fluctuations in seawater temperatures (ex: increase temperature);
- extreme low tides that dry coral out, disease and plagues
What are the Human caused threats ?
- Coral Harvesting to make jewellery, gift store curios, coffee table knick-knacks, and aquarium habitat. Under optimum conditions, many corals take 37 years to regenerate.
- Chemicals, such as chlorine-based cleaning solutions, heavy metals, and minerals from mining and other industrial pollution are poisonous to marine animals.
- Global Warming and the Greenhouse Effect Greenhouse gases are causing an increase in sea temperatures, sea levels, and violent storms negatively affect corals.
The weakened coral becomes more susceptible to disease and coral bleaching.
