Welcome to the first e-mail edition of Freshwater Update, produced by NIWA’s National Freshwater Centre. It's a quarterly review and outlook of New Zealand’s freshwater resources, and also features some of our latest freshwater research. In this edition, we feature our highly successful ‘Restoring aquatic environments’ programme.
Predicting which native fish species should be present in streams and rivers has just become much easier, thanks to new models developed by NIWA scientists. The models can help communities planning to restore waterways, and encourage the survival of rare native fish.
Lakes accumulate phosphorus (P) in their sediments, which is fine while the bottom water remains oxygenated. But, if conditions lead to algae accumulating in the lake, the decay of dead algae that settles to the lake bed and bottom water causes anoxia (absence of oxygen) at the bed. Then things go beyond a nasty tipping point.
Twenty years of monitoring provides insight into our river water quality
Two decades of monitoring of river water quality by NIWA has provided important information that is helping to care for New Zealand’s iconic rivers.
Read the full article.
Listen up! Polluted waterways – the science and the solutions
In a recent interview, NIWA scientists Drs Rob Davies-Colley and Bob Wilcock, and Murray Gibb (WaterNZ) talk about major water quality issues facing New Zealand, the latest research, and potential solutions to the problem of degraded water quality.
Northern North Island
Normal or above normal soil moisture levels
and above normal river flows are likely.
Rest of the North Island
Normal or above normal soil moisture flows and river levels are likely.
Northern and southwestern
South Island
Normal soil moisture levels and river flows are likely.
Eastern South Island
Normal or above normal soil moisture flows and river levels likely.
Maps of River flows, Lake Levels, Water Temperature and Water Clarity for March-June 2009.
Restoring life in degraded streams will be speeded up by tree plantings to provide shade, and by fencing waterways to keep animals out, NIWA research has confirmed.
A traditional Maori method of catching koura (freshwater crayfish) using a ‘tau koura’, or fern bundle, has worked well in koura abundance monitoring trials.
NIWA’s ‘Restoration of aquatic ecosystems’ research programme is the focus of a special issue of the New Zealand Journal of Freshwater and Marine research. Findings from the six-year research programme are important to water resource managers throughout New Zealand. It addresses key issues regarding what to do, where to do it, and how to go about stream, river, lake, and estuarine rehabilitation and restoration.
New NIWA research shows that adding logs into stream beds as part of waterway restoration could boost koura (freshwater crayfish) populations and speed up streams’ recovery.
