Key points

· The biological communities at each monitoring site were distinctly different from each other.

· Five estuaries were monitored including Whāngārei harbour, Kerikeri Inlet, Ruakaka estuary, Whangaroa harbour and Kaipara harbour.

· Metal concentrations complied with the Australian and NZ Guidelines for Freshwater Quality ANZECC at all monitoring sites.

· High nutrient levels were recorded in Whāngārei harbour and Kerikeri Inlet compared to other similar programmes in New Zealand.

· Further investigations will be undertaken to understand the factors influencing the biological communities.

Ruakaka Estuary.

Photo: Ruakaka Estuary