Why dune lakes are important
Dune lakes are rare ecosystem types on a global scale yet, Northland is home to over 400 of these lakes. While water quality and biodiversity are world-class in several of our dune lakes, many others are slowly degrading and need our help to recover.
About Northland’s dune lakes
Dune lakes are unique ecosystems, formed a few thousand years ago, when wind created hollows between dunes and this sand cemented with iron and aluminium leaching into a pan layer, or when sand dunes impounded a stream. They are rare and threatened ecosystems, both nationally and internationally. Some lakes, like Lake Taharoa of the Kai Iwi Lakes, are up to 60,000 years old.
The top 12 ecologically outstanding lakes in Northland are all dune lakes. However, there is a general trend of decline from a range of threats.
Threats to our dune lakes
Dune lakes are generally closed systems that are sensitive to external influences. Factors such as eutrophication (excess nutrient causing algal blooms), pest fish, aquatic weeds, land use, and water-take all contribute to declining water quality in our dune lakes.
The Freshwater Improvement Fund (administered by the Ministry for the Environment) Dune Lakes Water Quality Improvement Project aims to improve water quality in a number of Northland’s precious dune lakes.