Protecting lakes from weeds
1 July 2005
Protecting lakes from weeds, pest fish and algal blooms
New Zealand's lakes and the native fish and fresh-water plants in them are being threatened by invasive weeds, pest fish and algal blooms. A large research programme led by the University of Waikato will address these threats and enable lake restoration.
The research programme will receive $10 million over 10 years from the Foundation for Research, Science and Technology as part of its reinvestment in ecosystems research. The research will focus on the lakes in the Rotorua region, but the findings will be applicable more widely.
Native fish and plants are in decline in most New Zealand lakes. Not only do pest fish and weeds out-compete native species, they also alter the environment to cause proliferation of harmful algal blooms. Unfortunately, increased nutrient run-off from intensifying land use is both making algal blooms more likely and creating an environment that favours pest fish.
Toxic algal blooms have recently occurred in a wide range of lakes throughout New Zealand, and have in some cases resulted in water supply closure, cattle deaths and recreational closures of lakes. Researchers seek to develop tools that will enhance detection and understanding of bloom initiation and toxin production.
They also seek to understand the effect of nutrient run-off on algal blooms so that solutions for mitigating these impacts can be developed.
Pest fish degrade aquatic ecosystems by consuming and uprooting aquatic plants, stirring up bottom sediments and preying upon eggs of other fish species. The research programme will build new knowledge around controlling pest fish, working on effective toxins, bait delivery, capture and surveillance.
Ultimately this knowledge will lead to technologies relevant to community groups, councils, consultants and the water industry, who will be involved from the start to ensure methods to improve and protect New Zealand's lakes can be practically applied.
The Foundation's Group Manager of Investments, John Smart, says this research is very important as it has been recognised that indigenous biodiversity loss is one of the most pervasive of all environmental issues.
"This research will lead to a framework through which high quality lakes will remain stable and important degraded lakes may be restored."