Algae are photosynthetic plants that occur in most aquatic habitats. Like plants they have chlorophyll but they lack elements such as roots stems etc.  They vary from small, single-celled forms to complex multicellular forms, such as the giant kelps that grow to 65 meters in length. An example of micro-algae are phytoplankton and an example of macro-algae are sea weeds. Many algae can reproduce assexually meaning that populations of algae can grow extremely rapidly resulting in a very dense population of algae called an algal bloom.

 

Natural nutrient fluctuations can affect the carrying capacity of algae as more nutrients in the water provide more nitrogen and carbon etc, which are required for the algae's reproduction. Algae populations are diminished when they are exposed to long periods of high light intensity however have optimal growth when intermittently exposed to high light intensities. This means if there is an excess of sediment over the coral reef, the algae won't have enough light to grow, however if there isn't enough sediment or saltiness in the water the algae won' be able to survive the harsh light.  Algal blooms usually develop during the warmer months of the year or when the water temperature is higher. Marine algal occurrence also responds to nutrient enrichment, water circulation such as tides and currents, and wind patterns. The carrying capacity is also naturally affected by predators such as the angel fish and other small aquatic species.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After human's indirectly pollute the waters of the Great Barrier there is an influx of extra nutrients in the water which are often vital to the algae's survival. However, If the algae gets too much of these nutrients it will result in a rapid growth in the algae's population which is called an algal bloom. Algae is usually eaten by fish and starfish larvae, which acts as resistance against the growth of the algae. However, the algae are normally found in an area where there are often a release of sediments or pollutants by humans, that kill the fish populations or drive them away, therefore, there are fewer fish to eat the algae and so it grows at a faster rate.  The pollution we dump in the ocean is just what the algae needs to grow and be healthy, however, this is not necessarily healthy for the rest of the ecosystem.

 

If there is nothing done to prevent this, the algae will continue to grow at a rate that will not be able to be controlled. This will then block out light for other producers within the ecosystems.  This will have a large impact on the ecosystem and will then result in a complete imbalance of species in the ecosystem. This will then affect the algae as they may have less competition, allowing to grow more however other species could then become dependent on them or other species could die out due to the lack of food and thus there would be less species eating the algae.

 

One possible solution to this is to have a trawler that regularly goes through and skims the waters in which the algae habitat. This would lower the algae levels in the sea however, it doesn't prevent the problem from getting worse or even slow down the problem, it is more of a population check. This could also be problematic due to the fact it could damage other wildlife within the ecosystem. Another solution would be to boycott goods that have had pesticides or herbicides used on them as it will encourage the farmers to change the way they grow their crops. This is not only healthier for the environment but also for the people buying the products. This will slowly but surely reduce the amount of runoff pesticides that go into the water (this results in 5000 tonnes of nitrogen being dissolved in the water every year).  The nitrogen that is then in the water is one of the primary causes of the algal blooms, thus with less nitrogen in the water, the less algae there will be.

 

Algae is eaten mainly by the angel fish and other small fish. Algae are kept in check when they are eaten by Angel fish and due to the decrease of corals due to pollution by humans the angel fish population has decreased as corals are one of its food sources and hence algae has started to grow unchecked. Algae consumes sunlight and CO2 to grow. Algae grows on the surface of the water so that it can receive maximum CO2 and sunlight.