After 150 years of research, one might assume that we have a fairly complete picture of the invertebrate communities in New Zealand streams and rivers. However new research suggests that high altitude streams have distinctly different, poorly-known, biological communities.
NIWA scientists are presenting work at three national conferences in the next two months, the New Zealand Coastal Society conference 14th – 16th November, the New Zealand Hydrological Society conference 27th – 30th November and the New Zealand Freshwater Sciences Society conference,3rd – 7th December.
The three month flow map (on the right) shows that much of New Zealand experienced normal or above normal river flow conditions.
Intensive land use increases nutrient runoff to rivers, lakes and estuaries with adverse effects on ecosystems. Determining what combinations of land use and management enable the health and services of these ecosystems to be maintained or restored is a major challenge for councils.
River temperatures April to June
Autumn river water temperatures were mostly in the range 8 to 16oC and tended to be slightly higher in the north and at lower altitude.
Fine sediment loads delivered to estuaries by rivers are higher today than prior to catchment deforestation due to increased soil erosion. The effects on water clarity, which then impact sensitive estuarine ecosystems, are significant.
NIWA research on Mycoleptodiscus terrestris (Mt) shows the fungus could potentially be used as an environmentally safe "natural" herbicide.
NIWA is sponsoring the Irrigation New Zealand conference - building prosperity, opportunity and resilience for all.
The conference runs from the 2 - 4th April at the SBS events centre in Timaru. For more information see the Irrigation NZ website