The mysteries of Northland's dune lakes are being revealed using a canoe and some specialist hydro-acoustic surveying equipment.
Niwa scientists and Northland Regional Council staff are carrying out lakebed mapping of 25 dune lakes in a joint project that will provide data on depths as well as information on vegetation and sediment.
Councillor Monty Knight, who represents Te Hiku said that until now only a limited number of maps have been available, with even the most recent 35-years-old.
Some of the lakes were surveyed as long ago as the 1950s when techniques were not as advanced.
Niwa freshwater scientist Mary de Winton said Niwa is able to produce a map in a few days by subscribing to a specialist service in the United States which turns hydro-acoustic files into relief maps of the lake floor.