Attempts have been made to control spartina or cordgrass, at considerable expense, for many years. This man is checking a strip that was missed during spraying. With helicopters, amphibious vehicles and new herbicides, the Department of Conservation and district councils in Southland and Tasman have almost succeeded in eradicating spartina from these regions.

Spartina was planted in wetlands around New Zealand from 1913 to the 1950s in the hope of turning estuaries into grazable land.

However, estuaries are important spawning and feeding grounds for many marine and freshwater species, and feeding grounds for wading birds. They also buffer the impact of flooding.