They were an important food source for the Māori,[4] but like many freshwater mussels worldwide, are now endangered by pollution and eutrophication of rivers, and the introduction of new species of fish[5] leading to actions via the Treaty of Waitangi claims process.

[9][10][7] While Echyridella menziesii are parasitic as larvae, juveniles feed by grabbing food using their foot.

Adult Echyridella menziesii are filter feeders, feeding on phytoplankton, animal matter and bacteria.

[7] The destruction or modification of the habitat of the New Zealand freshwater mussel is likely to be a factor in the decline of its population.

This modification or destruction of freshwater habitat is also likely to be a factor in the decline in numbers of the mussel's host fish, the kōaro.