It was one of eight marine reserves established in 2005 as part of the management measures proposed by the Fiordland Marine Guardians.
Te Hapua Marine Reserve is the least studied reserve in Fiordland and probably one of the least visited. This is largely due to the shallow sill at the entrance to the fiord which makes accessing the reserve by boat dangerous as ocean waves often break across the shallow entrance.
During research carried out in a Fiordland-wide survey, the only reef fish observed at a study site in the reserve were spotties, while a full range of outer coast fishes were seen at the entrance.
This suggests that the reserve is mostly an estuarine habitat, and is probably home to animals such as spiky dogfish, stargazers, flounder and red decorative crabs. Future monitoring will provide us with a better understanding of the marine life in this area.