Freshwater Ecosystem- Eli LakesThe freshwater lakes located in the suburb of Eli Waters, Hervey Bay, is a lively ecosystem in which many organisms thrive. The main section of the lakes is in full sunlight and is approximately 450m in length, from one end to the other. Like all lake habitats, these freshwater lakes can be divided into four different zones; these include the littoral zone, limnetic zone, profundal zone, and benthic zone.The organism that I have chosen to study in further detail is Salvinia molesta, otherwise known as the salvinia weed. Salvinia is a serious aquatic weed that is very adaptable to a number of different environmental factors. The weed can be described as a ...view middle of the document...
The abundance of organisms, including salvinia weed, was examined around the lake. Photos were taken using the camera to provide evidence as to the lakes appearance on that day. Samples of various organisms were also collected and placed in sampling containers and bags. After being observed, the organisms appearance was recorded and then identified.The pH strips were used to conduct an initial test of the pH of the water on that given day. However, this method was not as accurate as the results in which a machine could produce.The data logger was used to perform various tests including water quality, water temperature, land temperature, air temperature and pH level. These samples were taken from different points around the lakes (see log book).A transect line was created by attaching the small piece of dowel to one end of the rope and attaching the larger piece of dowel to the other. The lakes highest ground point was where the end with the smaller piece of was placed. The larger dowel end was placed into the water at the shoreline, ensuring that the rope was completely stretched out. To be certain that the transect line was level, the spirit level was used. The metre ruler was then used to measure the height of the rope from the ground at metre intervals.Risk assessment:
Priority 1 (high) - 3 (low)
Observing the lakes
• Snake/spider bite
• Sharp/unknown objects
• Slipping/falling over
• Be cautious and responsible
• Ensure that the area you are in is safe by checking it for danger before you begin
• Ensure there is a first aid kit in your backpack at all times
• In the case that any of this does occur, leave the area and notify a teacher of the situation ASAP
Fishing from the lakes or being in closer proximity to the water
• Have at least one other person with you at all times
• If you cannot swim or are a weak swimmer, avoid being in situations in which you could fall in.
Taking samples from the lakes
• Coming into contact with harmful toxins in the water
• Avoid skin contact with the water unless completely necessary
• Use small shovel to collect samples • Wear protective equipment where necessary.
Initial manual pH level
Accurate pH level
Submerged soil temperature
Land soil temperature
Table 1- results from the data logger and manual methodsObservations Organism A: Floating lake plant with brown roots and green distinctive leaves. The leaves are covered in fine white hairs. This organism seems to form large mats over particular areas of the habitat, particularly near the shoreline.Organism B: Type of black bird with a red beak and red eyes. The neck is long and skinny and the feathers make an interesting pattern...