Freshwater

One of the most common barriers encountered by juvenile fish during their upstream migration are ‘perched’ culverts. This occurs when erosion downstream of a poorly installed culvert results in a drop forming at the end of the culvert.

Tau kōura is a traditional Māori fishing method commonly used to harvest kōura or freshwater crayfish in areas where they are abundant.

A whole of catchment Report Card for the Waikato and Waipa rivers has been released by the Waikato River Authority giving the catchment an anticipated low rating for its wellbeing.

NIWA researchers have spent part of the last month keeping a close eye on the bottom of Lake Tekapo to find out what it looks like and what is going on below the lake bed.

NIWA environmental monitoring technicians Evan Baddock and Eric Stevens venture deep into Fiordland, NZ to monitor river and lake levels in the area.

Three plants of an endemic submerged quillwort (Isoëtes) were recovered from Lake Ōmāpere by NIWA in 1998, prior to the lake weed (Egeria densa) dying off and the lake switching into an algal dominated turbid state. No further isoëtes plants have been observed in the lake since that time.

NIWA scientists and Northland Regional Council staff are uncovering more of the mysteries of the North’s prized dune lakes using a canoe and some specialist hydro-acoustic surveying equipment.

NIWA researchers have produced a series of calendars to inform people when New Zealand's native freshwater and sport fish are migrating and spawning.

NIWA's publication "Freshwater Fish Spawning and Migration Periods" is designed to help people working near freshwater to minimise effects of their work on freshwater fish species.

Now back on dry land, Voyage Leader Richard O'Driscoll reflects on the final days of RV Tangaroa's 2015 Antarctica expedition.

Water in the Blue Lake is the clearest freshwater ever reported.