The Great Barrier Reef Flashcards
Spatial Patterns of Great Barrier Reef:
- State/Country
- Length
- Area
- Longitude and Latitude
- Example of Biotic Life
- Extent of reef and cays
- Queensland Australia
- 23,000 km2 in length
- 344,000 km2 in area
- 8-24 S, 144-154 E
- 1,500 species of fish, 360 hard coral, 6 species of turtles
- 2900 reefs, 900 coral cays
List conditions for Coral Growth:
Hint 6 main conditions
- Depth of Water: 2-30m
- Temperature: 20-24 C
- Clear Water
- High Salinity
- High dissolved Oxygen level
- Low turbidity/sediment levels
Dynamics of Weather/Climate:
List biophysical processes occurring in GBR:
- Specific water temperatures
- High levels of rain lower salinity and increase turbidity
- Waves/Tidal currents- transport/deposits of sediments/nutrients
- Main direction of current is from South to North, this goes in reverse in monsoons. The reversal allows warm, high saline and nutrient rich waters into the reefs.
Dynamics of Weather/Climate:
Cyclones- Negative Impacts
- Rip apart soft corals, chips/breaks hard corals
- Increased rainfall leads to high runoffs:
* Increased chemicals–> Eutrophication
* Increased turbidity–> photosynthesis/smother
Dynamics of Weather/Climate
Cyclones- Positive Impacts
Cools down water temperatures–> helps to minimize coral bleaching
Oxgenate Waters
Geomorphic and Hydrological Processes:
List features and impacts of:
- Reefs produce solid limestone (skeletal remains of corals)
- Fish species (Parrot Fish) break down coral
- Weathered coral is transported to coral cays
-Runoff/Sediments increase turbidity, when combined with chemicals it devastates the reef
Biogeographical Processes:
What are the two main concepts? List features and Examples.
- Species Interactions
- More than 300 species of coral
- Beneficial relationship between coral/polyps and Zooxanthellae
- Zooxanthellae gives the coral their bright colours (limited tolerance to heat–>Coral Bleaching) - Ecological Succession
- Coral builds upon the remains of the former coral
Impacts Due to Natural Stress:
Tropical Cyclones Case Study: Yasi
Date: 29/1/2011-3/2/2011
Wind Speed: Max gust: 285 km/h, Max sustained: 205 km/h
Eye: Tully
Rainfall: 200-300mm in 24hrs. South Mission Beach had 471mm.
Impacts Due to Natural Stress:
Crown of Thorns Starfish:
- Consumes large amounts of coral
- Natural, however more damaging when reef is already stressed
- Responsible for greater decline in coral cover than any other threat
- Outbreaks start in the N and head S over a 15yr period.
- Healthy reefs recover between 10-20yrs. Not so healthy take longer.
List the 5 Negative Human Impacts:
- Mining and Shipping
- Over-fishing
- Agriculture/Land Clearing
- Tourism
- Climate Change
Mining and Shipping:
List some resources Queensland Has
Gladstone Harbour Info
- QLD home to natural resources e.g. (Coal, Ur, Liquid Natural Gas) –> Shipped to India and China
- Gladstone Harbour, made deeper through dredging
- Dredging increased turbidity of soil and stirred up heavy metals in the water, leading to bio accumulation (remember that fish video)
- Increased shipping increases the risk of grounding and risk of oil spills e.g. Shen Neng 2010 ran aground spilling oil
Agriculture/Land Clearing:
How many river systems flow out to GBR
Importance of Wetlands
Impacts of Farming
- 26 river systems flow into GBR
- Wetlands provide important habitats for species of wildlife, they also retain large amounts of fresh water during heavy rain fall
- Wetlands also act as a buffer zone and filter out sediments heading out to the sea
- Farming can release chemicals, diseases, sediments that cause Eutrophication, high turbidity, pollution to GBR
Climate Change:
Impacts
- Seas Warming–>Coral Bleaching, Sensetive Corals die.
- More Extreme Weather –>Coral Destruction
- Increased Flooding–>Increased Turbidity/Runoff
- Increased Coral disease
- Sea Levels Rising
- Gradual Acidification of Oceans
Coral Bleaching Event 2002:
- 55% of over 640 reefs showed coral bleaching
- Impacts of bleaching were not evenly distributed
- Most severe were on reefs closest to shore
- 2002 bleaching event affected greater area of offshore reefs
Tourism:
Is the major contributed to local and national economy. It produces $5 billion a year and thousands of jobs.
- List Activities undertaken in the GBR region
- Dangers of Tourism
1.
- Day tours
- Snorkeling
- Scuba Diving
- Boating
- Whale Watching
- Swimming with Dolphins
2. Pollution, Poaching, Destruction of Coral etc.