Large River & Floodplain Ecology

Large river and floodplain research programme

Large lowland rivers often have extensive floodplains that include wetlands, lakes and tributaries which are flooded during high flows. Interactions between rivers and their floodplain habitats are now controlled by networks of stop banks, flood gates and tide gates, and river-floodplain ecosystems generally have undergone significant modification due to land-use change, flow regulation and drainage. These iconic rivers and their floodplains play a pivotal role is sustaining estuarine and upstream aquatic ecosystems, as well as providing a range of ecosystem services such as drinking water, fisheries, flood conveyance and contaminant attenuation. There is increasing concern worldwide over the ecological condition of large rivers and their ability to sustain these services, and growing interest in approaches to rehabilitation. However, little is known about the ways the biology or functional processes in large rivers respond to human pressures and restoration measures, or the constraints to floodplain reconnection in modified environments.

Image: Huntly

We are conducting a suite of ongoing studies to address various issues related to:

  • measuring the effects of various human pressures on river ecology and floodplain habitats

  • developing sampling methodologies and ecological indicators for monitoring large river and floodplain health

  • understanding food-webs and energy pathways fuelling fish nutrition

  • investigating the role of floodplain inundation on food production and larval fish recruitment

  • evaluating the effectiveness of restoration and management approaches

This work is focussing mainly on the Waikato River, but has also included a range of
other large rivers spread around the country.

Map of large (>= 6th order) New Zealand rivers (those sampled as part of a national large rivers survey are named (see report)