Kākahi are filter feeding animals and help to improve water quality by reducing algae and sediment in the water. Lake Wairarapa has two of the three species that are known to live in New Zealand. Populations of käkahi are in decline throughout New Zealand, and throughout the world. In New Zealand this decline is linked to the deterioration of the water quality in lakes and rivers. So, the health of a kākahi population helps to gauge ecosystem health of a lake or wetland.

Monitoring the health of Wairarapa Moana is an essential part of a long-term plan towards restoring our wetland treasure. The status and health of the kākahi (native freshwater mussel) population helps us understand the health of the wider ecosystem and can measure the progress of restoration activities.