Abiotic Factors
SunlightThe Great Barrier Reef has mostly shallow waters so that it is easier for light to penetrate the water to reach organisms that need it most. Most life needs rich sunlight in order to survive in the reef, so you can find more living organisms in this area, which is known as the "photic zone". This zone is where most producers, like algae, are found due to their need for sunlight to produce glucose.
Light penetrationAccording to Queensland Museum, Australia, the average amount of light penetration through seawater is only 20 metres or so from the ocean surface. "Red light gets absorbed first by water and blue light penetrates the farthest". This means that red light is quicker to be filtered through water as it gets deeper, in comparison with blue light which penetrates best.
TemperatureIt is vital that the temperature of the Great Barrier Reef is maintained at a safe level, otherwise there will be dire consequences, as we are already seeing with excess human pollution. Green house gas being released into the atmosphere is being trapped in the troposphere, meaning there are excessive amounts of heat being culminated there. This can prevent "heat from escaping the atmosphere and is one of the causes of global warming". The rise is external temperature is effecting the water temperature of the reef and their is significant evidence (research done by the Great Barrier Reef Marine Park Authority which is part of the Australian Government and Australian Institute of Marine Science) to show that climate change is putting stress on delicate coral colonies and destroying the delicate balance of this ecosystem.
Coral bleaching, a suspected effect of global warming, occurs when the coral's protective layer of algae dies off. This exposes the coral's exoskeleton, which is pale white. |
Temperature variationIt is important to note that there are less temperature changes in this biome in comparison with land habitats, so sea temperatures are of lesser extremes. We can see by observing the table below that both maximum and minimum temperatures do not fluctuate more than 7 degrees below 31 degrees Celsius, and so the temperature variation on the Great Barrier Reef is quite moderate.
Salinity3.5% is the average salt content in seawater and the salinity levels in the Great Barrier Reef average at approximately 35 parts/1000. High levels of salinity are vital for optimum coral growth, and so one of the biggest problems problems related to salinity levels in coral reefs is the possibility that heavy rainfall with cause "fresh water ponding", which in turn can kill coral exposed during low tide.
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Rainfall
Heavy tropical rainfall can cause flooding in rivers and wash down chemicals eg. fertiliser, into the sea. The average amount of rainfall in Tropical North Queensland is 2010mm, which adds up to an average of 168mm per month.
Wind
On a coral reef, wind plays an important role in shaping individual reefs through Aeolian erosion, not to mention the role wind plays in changing wave formation and currents. The Great Barrier Reef experiences below average wind speeds compared to the rest of Australia, although the reef has seasonal summer cyclones.
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