Botany Bay Ecosystem
Banksias and Beyond
Biotic and Abiotic Factors
Some biotic factors that can be found in the Botany Bay ecosystem are:
- Sea Grass beds
- Strap weed
Mangroves: Mangroves are trees that grow in swamps and wetlands that are reached by the sea water during tide changes. They are a habitat and food source for many organisms including birds, crustaceans, fish and mollusc. They produce a sufficient quantity of leaf litter (dead plant material) which is often consumed by creatures like crabs, before the leaf litter is broken down and becomes food for smaller organisms.
Sea grass beds: Sea grass beds grow at the low tide mark in sheltered bays and estuaries. They have a mat like root system, resemble grass or seaweed in appearance and serve a number of different purposes. They provide food, shelter, safety and also gives predators easy access to food.
Strap weed: Strap weed is a type of weed that grows in sea grass beds. They are host to many organisms including tube worms, sponges and epiphytes. Strap weed is able to filter water and has large spreading roots which are strong enough to hold down sand.
are all abiotic factors that have an effect on the Botany Bay Ecosystem.
Temperature: The temperature in Botany Bay varies throughout the year (though it is mostly below 20 degrees Celsius) , and also varies in different locations like the estuary, mangroves and sand dunes. It has an effect on organisms bodies and their behaviour, the climate they live in and also the plants.
Salinity: The salinity of water in different locations like the estuary, fresh water area and sea have an effect on how organisms and plants. Organisms in high-salinity water have adapted so that they can excrete the excess salt that their bodies are exposed to. Salinity also effects plant growth and function.
Tides: Tides are caused by the moon. There are four tides that occur every 24 hours, two low tides and two high tides. Tides have an affect on many things, including how animals and plants adapt, the behaviour of animals and opportunities for organisms to feed and shelter.
Typical Organisms Which Live in Botany Bay
- Blue Swimmer Crab
- Pipe fish
- Red Fingered Mud Crab
- Dumpling Squid
- Blue-lined Octopus
Human Impacts and Threats
The Botany Bay Ecosystem has been greatly impacted by human activity, especially over the last 50 years. This is mainly because of the airport and seaports which have been built in / next to Botany Bay. These buildings along with a number of factories that have been built along the Botany Bay water body are threatening the Botany Bay Ecosystem. The three main ways humans are impacting the ecosystem are:
- Water pollution
- Noise / sound pollution
- Trampling / human carelessness
An oil spill in a body of water
An airplane creating noise pollution for animals living in this harbour
A small crab like this could be trampled by a human
Red Fingered Mud Crab
Scientific Name, Habitat and Diet
Scientific Name: Sesarma erythrodactyla
Habitat: The Red Fingered Mud Crab lives in cool/shaded, wet and muddy places like marshes, mangroves, salt marshes and river banks.
Diet: Red Fingered Mud Crabs are omnivores, meaning they eat both plants and animals. As for plants, this crab eats mostly leaf litter (dead plant material), bacteria and algae. They also eat smaller crustaceans (such as) and "dead things" or detritus (i.e. organisms that are found dead and have not been killed by the crab).
As seen in the photo above, the red fingered mud crab has a green shell. This feature is an adaptation of the crab. It uses this green shell to blend into the speicifc species of mangrove found in Botany Bay, the grey mangrove.
The crab also has large nippers which it uses to defend itself against larger crabs and other predators. These nippers are also used to intimidate and hunt smaller crustaceans for food. Large nippers are an adaptation of this crab.
Blue Lined Octopus
Scientific Name, Habitat and Diet
Scientific Name: Hapalochlaena fasciata
Habitat: Blue-lined octopi live in dark and cool places, mainly in rock crevices and dead shells. They can be found only in Australia (they are native), more specifically from southern Queensland to southern New South Wales.
Diet: This species of octopus is carnivorous and feeds mostly on crabs and other crustaceans such as krill and barnacles.
This octopus has the ability to show blue rings of colour on its body when it is aggravated. This is useful to the octopus as it can intimidate its prey and also act as a warning to any animals preying on the octopus. This adaptation keeps the octopus safe and allows it to hunt easier.
When the octopus is not aggravated, it is perfectly camouflaged with sand, mud and other similar coloured surroundings. This adaptation makes it easy for the octopus to prey on organisms and stay hidden from predators.
- [Accessed 5 September 2016].http://www.qm.qld.gov.au/Find+out+about/Animals+of+Queensland/Molluscs/Cephalopods/Blue-lined+Octopus#.V9kfaY9OJhg. [ONLINE] Available at: Blue-lined Octopus - Queensland Museum Blue-lined Octopus - Queensland Museum . 2016.
- [Accessed 5 September 2016].http://www.georgesrivereec.com.au/index.php/resources/significantfauna/list-of-selected-fauna?id=314. [ONLINE] Available at: Red-fingered Marsh Crab - Georges River EECPamela Melrose. 2016.
- . [Accessed 7 September 2016].http://www.botanybay-e.schools.nsw.edu.au/resources. [ONLINE] Available at: Resources - Botany Bay EECResources - Botany Bay EEC. 2016.
- The booklet "Living World in the Wetland Ecosystem -Botany Bay-" which contains information recorded about the Botany Bay Ecosystem on an excursion to Bonna Point, Botany Bay.
- . [Accessed 10 September 2016].http://www.environment.nsw.gov.au/beach/ar0708/botanybay.htm. [ONLINE] Available at: Botany Bay | NSW Environment & HeritageBotany Bay | NSW Environment & Heritage. 2016.
- . [Accessed 10 September 2016].https://en.wikipedia.org/wiki/Botany_Bay. [ONLINE] Available at: Botany Bay - Wikipedia, the free encyclopediaWikipedia. 2016.