The Waikato region has a large coastal marine area, which covers over 10,000 km2 in area and includes around 1,150 km of coastline. Many harbours and estuaries (33) occur on both the west coast (Port Waikato to Mokau) and east coast (Firth of Thames and Coromandel Peninsula) of the region.
The catchment type surrounding Waikato estuaries is a mix of pastoral, exotic forestry, natural and urban (low in the Waikato Region 0 - 5%). Four estuaries are currently monitored, varying in size from medium to very large. Intertidal sediment-dwelling organisms (macrofauna - including shellfish and marine worms) and sediment characteristics are used to monitor estuary health. Overall the Waikato estuary sites are in good health.