Freshwater and Estuaries research projects

Read more about our freshwater and estuaries research. 

An experiment in Henderson Creek, Auckland, has demonstrated how tidal creeks variously import, export and deposit sediment, depending on the wind and freshwater runoff, and modulated by the tide.
Mangrove forests, which are important parts of estuarine ecosystems in a number of ways, are sensitive to changing sea level.
Aquatic systems are under threat due to the introduction of invasive exotic species such as water weeds. Modelling work by NIWA has provided new information on which water bodies may be at greatest risk.
NIWA has developed a rapid, desktop model which assesses the potential impact of introducing new fish species to New Zealand. The model is customised to New Zealand's unique environment and endemic fish.
New Zealand's geographic isolation and relatively recent colonization provide the opportunity for a unique genetic analysis of plant movement patterns to be explored.
Estuaries in New Zealand are experiencing sedimentation at higher rates than before humans arrived here: this represents a loss both for land and estuary productivity. We need to better understand what has been happening so that we can predict the future and fight these losses.
A significant threat to the biosecurity of New Zealand's freshwater habitats comes from plants that have been intentionally introduced.
River plumes form one of the primary connectors between river-estuary systems and the coastal ocean.
A Ministry for Primary Industries-funded study has shown that grass carp, in enclosures, can be used as an effective means of controlling invasive plant species in our waterways.
Many of New Zealand's aquatic ecosystems, and their services, are in a degraded and often worsening state. NIWA is involved in research and consultation' aimed at improving the health of our freshwater systems.
A project funded by West Coast Regional Council has increased our knowledge of the role of phosphorus in determining water quality in Lake Brunner.

How will water resources in the water-limited parts of New Zealand, such as Canterbury and Hawkes Bay, look in the future?

Many New Zealand lakes are suffering from nutrient enrichment, causing potentially toxic blooms of blue-green algae. NIWA is testing a range of methods to manage phosphorus release from lake sediments – including sediment-capping agents.
Gathering, eating and sharing wild kai (food) has always been a very important part of Māori culture and wellbeing - this research project aimed to characterise the risks associated with consuming kai collected from rivers, lakes and coastlines.
This project involves the development of a computer-based framework for freshwater models. The framework will be tested to proof-of-concept stage.
Many of New Zealand's rivers fail to meet national guidelines for nutrient levels. NIWA has developed the Catchment Land Use & Environmental Sustainability (CLUES) estuary tool to predict the effects of land use on estuarine nutrient concentrations.
Understanding the relationship between hydrological processes and stream ecology is vital for the sustainable management of the water sources that support Lake Ellesmere.
NIWA has produced revised safe levels of dissolved oxygen for fish, which will help inform future environmental planning and resource consents and help to keep New Zealand rivers full of healthy fish.
Streams play a key role in the ecosystems of New Zealand’s unique landscape. They feed and link together freshwater sources, maintain good water quality and support habitats that sustain our biodiversity.
Changes to the local environment and over harvesting have damaged shellfish populations in many estuaries. These projects examine the most effective way to restore these habitats and allow healthy populations of shellfish to return.