Natural disasters
Mount Ruapehu is one of the most active volcanoes in the world. If there was a large eruption, the ash and material ejected into the surrounding Taupō area could get into local waterways. This material could pollute the rivers and lakes and kill the organisms living in them.
Storms and flooding could also affect the quality of the local waterways with large amounts of silt being carried into the rivers and lakes. The silt could make it difficult for water creatures to breathe and hunt for food.
Human impacts
Modification of waterways
One of the biggest threats to freshwater ecology around the world is from water being diverted from its natural course for the purpose of irrigation, water supply and the production of energy.
Urbanisation
When it rains in urban areas, the rain that runs off buildings and down gutters is called storm water run-off. Storm water run-off can carry pollutants, either chemical or natural (silts), back into the local waterways. For this reason the management of storm water quality is of great importance for urban development and resource planning.
- Find out more about native fish in urban waterways and what you can do to help.
Nitrogen
Over the last fifty years, land and industrial development in the Taupō region has increased the amount of nitrogen in the water. Nitrogen encourages the growth of algae, which makes the water murky. The health of Lake Taupō and its rivers, and the future of the trout fishery, depends upon clean, clear water. The Lake Taupō Protection Project aims to reduce the amount of nitrogen entering the water by 20% over the next 12 years.
Over-fishing
Over-fishing can take a species out of the food web. The health of a waterway can be measured by how many different types of living things it contains. If a species is over-fished this will affect other parts of the food web.
