No.02 2003

Lake Hauroko, Fiordland
The absence of exotic oxygen weed allows the native Callitriche petriei to form extensive cover to depths of several metres in some locations.
Salmonids are one of the few introductions to Lake Hauroko.
Lake Hauroko contains some of the best examples of freshwater sponges in New Zealand.
A mixture of native species at a depth of 3 m. The dominant plants here are Isoetes alpinus, Myriophyllum triphyllum, and Potamogeton cheesemanii.
Native bullies among shallow rocks and plants.

Using invertebrates to assess stream quality – the trade-off between cost and accuracy
A NIWA team sampling and sorting stream macroinvertebrates.
Landuse management practices, such as those associated with forestry or pastoral development, can put considerable pressure on freshwater ecosystems.

Water resources in summer 2002–03
River flow
River flows over last summer were below normal or near normal for much of the country.

Canterbury Strategic Water Study
Canterbury consumes more water than any other part of New Zealand – 290 m3/s are allocated for abstraction from rivers and groundwater, and demand could double. Yet there is no strategic plan that integrates long-term development with the maintenance or enhancement of Canterbury’s water-environment values.

The need for research in water allocation
In January this year the Government identified four linked issues to be addressed in their “Programme of Action” for the sustainable development of New Zealand: water quality and allocation, energy, sustainable cities, and child and youth development. The science community is well prepared to tackle water quality and allocation, and this issue of Water Resources Update provides some pointers.
In comparison with many other countries, New Zealand is remarkably free of disputes over water.