Coasts Flashcards
(20 cards)
What is a coral?
> a marine animal called polyps that secrete calcium carbonate and build reefs
symbiotic relationship with algae.
- algae provides nutrients, energy and O2 (NEO+C) + colour
- coral provides protection, nutrients and CO2
What do corals need to form and why?
> clear, shallow saltwater
- need algae to photosynthesise for energy
23-25℃ waters
- algae cannot survive in too hot waters and will cause coral bleaching
lots of sunlight
- for algae to photosynthesise
What is a fringing reef? Give an example.
> coral platforms grow out to sea attached to the mainland
shallow lagoon lies above them
NINGALOO REEF: WESTERN AUSTRALIA
What is a barrier reef? Give an example.
> grows off the mainland on shallower areas
THE GREAT BARRIER REEF: AUSTRALIA
What is an atoll? Give an example.
> fringing reef grow in a circle attached to an island
sea level rise or subsidence of the land causes coral to grow at the height of the rising sea level to reach the light
eventually forms a ring of coral reefs with a lagoon replacing the island in the centre
- different to fringing as the land has gone
BLUE HOLE LIGHTHOUSE REEF ATOLL: BELIZE
CS: GBR. about the reef:
> north-eastern coast of Australia
2,300 km long
made up of a lot of individual reefs
The Great Barrier Reef Marine Park Authority (1981) manages it
CS: GBR. How do humans use the reef?
> Fishing - only allowed in 2/3 of the reef - cyanide bombs used to stun fish > Tourism - snorkelling and scuba diving - tours, kayaks, cruise ships, yachts - generates around A$5 billion
CS: GBR. How are they under threat?
> Industry and sewage
- toxic and metal pollutants cause algal blooms and eutrophication (this is also caused by nutrients from farms)
Tourism
- standing, bumping into while snorkelling, ignoring advice
Dredging (+ Housing and shoreline development)
-sediments cloud water, algae die from lack of sunlight
[global warming causes starfish expansion which feed on the algae and corals]
CS: GBR. How is the GBRMPA trying to manage the reef in a sustainable way?
> developing laws against oil pollution, over-fishing and tourist damage
zoning areas for particular activities
What is the definition of bleaching?
a process where coral loses its colour due to changes in conditions (temperature, light, nutrients), algae leaves the coral which causes the loss of colour
What is the definition of eutrophication?
excessive richness of nutrients in water due to frequent run-off from the land, which causes a dense growth of plant life
What is the definition of sediment?
solid material that is moved and deposited in a new location. It can be made up of rocks, minerals and remains of plants and animals
What is the definition of sustainability?
understanding how to meet the needs of the present without compromising the needs of future generations to meet their own needs
What are mangroves?
> halophytes
tropical plants
evergeen trees
What sort of conditions do mangroves need to thrive?
> calm water
temperatures > 20℃ and seasonal changes <5℃
salty water
Where are mangroves generally in the world?
> tropical locations
75% coasts cover
42% in North Australia
What are some environmental benefits of the mangroves?
> shelter, feeding, breeding for fish and other wildlife
natural defense against erosion
produce tannic acid
- apparently linked with preserving coral reefs
What are the economic benefits of the mangroves?
> provides around 75% of game fish and 90% commercial fish in South Florida
makes durable, water resistant furniture
leaves make medicine, tea and sub. for tobacco
How are mangroves threatened by humans?
> TOURISM - beaches, hotels, golf courses
used as a dumping ground for rubbish
barricading water for irrigation systems
will be gone in around 100 years
Where and how are mangroves being protected?
> World Land Trust helped PRRCF to replant mangroves on the adjacent island of Negros
Australia
- protected by marine parks, national parks, fish habitat areas
spreading awareness on importance of mangroves
communities learning how to protect and how to use the mangroves in a sustainable way
