Freshwater Update 85, March 2021

Models are needed because it is impossible to directly observe environmental variables at all locations, all the time or in the future. Hydrological models can make reliable predictions in ungauged catchments and about future conditions.

At night, in the NIWA lab in Hamilton, lamprey have been climbing structures to help scientists understand how they can navigate waterways.

New Zealand’s population is increasingly urban. As of 2018, major urban areas in Aotearoa accounted for more than half of the population. As the population grows and urban development expands and intensifies, freshwater environments in urban areas are coming under increasing pressure.

Eutrophication refers to increasing levels of plant nutrients in a water body, and increasing risks that algae and aquatic plants will growth to nuisance levels and degrade water quality.

NIWA scientists Dr Andrew Swales, Dr Rob Bell and Dr Drew Lohrer wrote a chapter on estuaries for the NZ Coastal Society sea-level rise special publication in late 2020 called Estuaries and lowland brackish habitats.

I am a Principal Scientist of freshwater fish. I specialise in fish ecology, particularly lamprey (kanakana/piharau) and whitebait species, and the use of pheromones/semio-chemicals for population monitoring, enhancement and control.

Principal Scientist Paul Champion took Kennedy Warne of New Zealand Geographic along on a monitoring survey of the precious Lake Ngatu. The dune lake is a taonga to local iwi and the freshwater biosecurity team monitor the ecological health of the local lakes in partnership with Northland Regional Council and tangata whenua.