The Hawke’s Bay coastline stretches 353km from Mahanga on the Mahia Peninsula in the north to Whangaehu in the south. It supports a number of coastal estuary systems that form the combined mouth of the land and freshwater drainage system before it goes out to the ocean. Estuaries in this region include significant wildlife habitats and one of the least modified estuaries on the east coast. These estuaries are highly valued for their recreational use and as places to harvest kai.
Hawke's Bay Regional Council monitors 6 estuaries at 10 sites across the region to characterize and track their health to understand the impacts of land use on the coastal environment.
Hawke's Bay's estuaries are classified into two hydrosystem types. Shallow Intertidal Dominated Estuaries (SIDE) include Ahuriri Estuary, Maungawhio Lagoon, and Pōrangahau Estuary. SIDE estuaries may be more sensitive to the addition of nutrients and contaminants than river mouth estuaries as they tend to retain water for longer. Shallow, Short Residence Tidal River Estuaries (SSRTRE, or river mouths) include Wairoa, Waitangi, and Tukituki Estuaries. Water passes quickly through these estuaries to the ocean.