| Estuaries are important sites for many biological and physical processes, yet they are often taken for granted. They act as “service centres” for nutrient cycling, they are a source of fish and shellfish for human consumption, and they provide nurseries for juvenile fish and birds. These ecosystems can also act as “sinks” for land-generated sediments and contaminants. | 
Ahuriri Estuary |
New Zealand’s expanding population, migration to coastal urban centres, and changing land use from rural to residential and urban, have meant that our estuaries and their fringing habitats are under increasing threat. Estuaries and harbours are particularly prone to pollution from intensified land use, urbanisation (sewage and polluted urban run-off) and industrial development. Harbours are also subject to the risk of pollution and introduction of new organisms through discharges by ships of effluents and ballast water.
| A number of key estuaries in Hawke’s Bay are part of the Wetland Enhancement and Management Programme, run by the Land Management Section. To determine the effectiveness of the enhancement programmes, these estuaries are monitored biennially (every two years). Monitoring includes mapping of the terrestrial vegetation including weeds and rare species, monitoring of birdlife, fish, aquatic invertebrates and any pest species present. This monitoring programme is currently being reviewed. | 
Whakamahi Lagoon |
| A great deal of monitoring has been carried out over the years on the lagoons, ponds, tidal flats, saltmarsh islets, and channels which make up the 275 ha (high tide) Ahuriri Estuary. This estuary supports a rich diversity of bird and fish species and has been declared a Wildlife Refuge. The estuary receives stormwater runoff from the majority of the Napier-Taradale urban and industrial areas, and also rural runoff from pasture lands adjacent to the upper estuary. Siltation occurs at the entrance to the inner harbour, which is periodically dredged. | 
Whakaki Lagoon |