Devilbend Foundation volunteers are working with Melbourne Water / Water Watch Victoria,
helping to keep Devilbend Natural Features Reserve special.
We encourage you to fully explore Water Watch Victoria's website to learn more and get involved.
Above & below image taken by Hansi Wegner
Water temperature plays a very important role in the health and quality of a water body. Temperature can affect the biological, chemical and physical features of a river. The amount of oxygen that can be dissolved in water, the rate of photosynthesis by plants and algae and also the sensitivity of aquatic organisms to toxic wastes and disease can all be influenced by water temperature.
Dissolved Oxygen is essential for a healthy and diverse waterbody. Aquatic organisms and plants need oxygen to survive just as we do. Waters with consistently high dissolved oxygen levels (between 80 and 100%) are considered healthy and stable, capable of supporting a large variety of aquatic organisms. Dissolved oxygen in water mainly comes from the atmosphere. Waves, ripples and tumbling water mix with the oxygen in the air so that the oxygen dissolves in the water. Photosynthesis by algae and aquatic plants also produces oxygen for the water. In water bodies where there is extensive plant growth the dissolved oxygen levels can be monitored throughout the day and the effects of photosynthesis observed.
Turbidity measures the clarity of the water. An increase in suspended matter increases the turbidity of the water. High turbidity causes water to appear murky or cloudy. Turbidity limits the amount of light able to penetrate through the water, which can effect plant growth by reducing the plants ability to produce food via photosynthesis. The suspended matter mainly consists of inorganic and organic material made up of algae, storm water runoff in urban areas and soil particles from erosion or the weathering of rocks. Soil erosion is a major input of sediments into a waterway. Removal of stream bank vegetation can mean soil is more easily washed into a waterway causing erosion and an increase in turbidity. Live stock using stream banks as access to water can also contribute sediments through erosion. Limiting stock access by fences can reduce the amount of bank erosion inturn reducing sediment input. Waste discharge through urban runoff can wash sediments off roads and drains increasing turbidity. High algal growth can also led to an increase in turbidity, as can an abundance of destructive bottom feeders such as carp.
Conductivity measures the amount of dissolved ions such as, Calcium, Magnesium, Potassium, Chlorides and Bicarbonates that are present in a waterbody. It is measured by placing a conductivity probe in the sample and measuring the flow of electricity between the electrodes. Conductivity is reported as EC units and the units used are usually given as microsiemens per centimetre (μS/cm). Conductivity is sometimes easily confused with salinity (units for salinity are mg/L). When you measure EC you are not doing salinity but a salinity result can be estimated by multiplying the EC result by 0.64. Salinity problems occur when deep rooted vegetation is removed from the surface and through irrigation practices. What occurs is that much more water can infiltrate the soil and causes the water table to rise. The water can move towards the surface, bringing with it large amounts of salt from underground storage. After the water evaporates, high concentrations of salt remain which can eventually find its way into waterways. Many aquatic species can survive only within certain salinity ranges so changes in salinity levels may result in changes to the variety and types of species present.
Phosphorus is a nutrient that occurs naturally at low concentrations in water and is essential for life. Phosphorus comes from the weathering of rocks and from the decomposition of organic matter such as plant litter. Phosphorus is present in streams as soluble phosphates, phosphorus bound to sediments and phosphates occurring in living organisms. Increases in phosphorus levels in streams may result from erosion, discharge of sewage, detergents, urban stormwater, rural runoff containing fertilizers and animal and plant material. Where there is an excessive amount of phosphorus in the water, algal blooms can be a serious problem. Blue-green algal blooms can have the potential to be extremely toxic to humans and live stock. Phosphorus comes from a variety of sources including, human and animal wastes, industrial waste and disturbance of land and it’s vegetation by natural or human influences.
Nitrogen makes up about 80% of the air we breathe. It is an essential component of most biological processes. Inorganic nitrogen may exist in the free state as a gas, or as nitrites, nitrates or ammonia. Organic nitrogen is found in proteins and other compounds and represents a potential source of available Nitrogen, this organic nitrogen may be utilised by bacteria. Nitrites are relatively short lived because they are quickly converted to nitrates by bacteria. The delicate balance of an ecosystem can be upset when nitrogen concentrations become too high. Resulting problems can include algal blooms, loss of species diversity excessive growth of aquatic weeds. Natural levels of nitrogen in the form of nitrate and nitrite are usually low in rivers and streams (<0.75 mg/L total-N). Elevated levels can mostly be attributed to diffuse or point source pollution. As nitrates are soluble in water they are easily leached out of soil and washed into nearby waterways.
There are four key Monitoring Points around
Devilbend and Bittern Reserves