Ki uta ki tai: Managing catchments for Healthy Estuaries

This research provided a new, national overview of the current state of the estuaries.

About 60% of NZ estuary catchments do not meet the NPS-FM bottom line for Total Nitrogen and 70% do not meet the Total Phosphorous bottom line standards for rivers.

This study went on to determine that reducing the nitrogen load by 60% would result in more than 80% of estuary catchments achieving the Nitrogen NPS-FM bottom line. To achieve this, land managers in those catchments would need to implement runoff mitigation strategies, such as riparian planting, and consider some land-use diversification.

However, it highlights that modelling using financially viable land use options to estimate the land use change required in catchments to reach the NPS-FM bottom lines shows land in forestry increasing significantly. There are many reasons why that outcome is not palatable for Aotearoa.