AHURIRI ESTUARY - A healthier estuary for fish, birds and people
Ahuriri Estuary is national treasure - home to native and migratory birds and a nursery for ocean going fish and a popular recreation area. The TANK Interim Agreement recognises the Ahuriri Estuary as a site of ecological, cultural and recreational significance, and recommends all reasonable measures to be undertaken to support these uses and values.
What do want to fix?
Fresh water flowing into the estuary brings sediment with it from surrounding land but this impacts the fish habitats.
Nearby urban and industrial areas mean contaminants come through untreated stormwater drains directly into the estuary. There is a build up of chemicals stored in the estuary muds from decades of industrial contamination and there can still be occasional sewage or chemical spills impacting the estuary. Shellfish gathering in the estuary is regularly banned because of contamination.
Accidental oil spills from boats in the Inner Harbour are also a risk to water quality and wild life, and pollution response teams regularly practice reducing this threat.
What do we want to do?
We want to restore the estuary to good health, working with Napier City Council, Maori, Department of Conservation and other landowners and businesses in this area.
We want clean up the water entering the estuary. We need to work on limiting the amount of sediment by planting to reduce erosion and trap sediment flows. Businesses are much more aware of the risks of contamination through stormwater but continued best management is needed. Homeowners need to be more aware of the cumulative risks from material they put into stormwater.
We want to remove pests – both predator animals and invasive weeds.
Our work so far
Ahuriri Catchment Land Action Plan - We have completed the plan for sediment and nutrient control, and this identifies high erosion risk land within the catchment. We are working with 14 landowners within the catchment. Ginny and Lloyd Cave recently collected 600 eco-sourced native plants from Plant Hawke's Bay nursery owner Marie Taylor for their riparian work (photo May 2018).
Hydrology research - We are scoping further research into the hydrology in the catchment – how much water comes through, where from and where to, including what are the contaminant pathways and how much healthy freshwater the estuary needs to function.
Invasive tubeworm control - We have worked with the Mana Ahuriri Trust to remove 219 tonnes of invasive marine tubeworm (Ficopomatus enigmaticus) from the estuary to improve water flow and quality.