Fiordland’s ten marine reserves range in size from 93 to 3,672  hectares, and in total include over 10,000 hectares of inner fiord marine habitat. The reserves border the Fiordland National Park and are a fantastic example of natural environments protected from the peaks of mountains to great depths of the fiords.

The marine reserves include a huge variety of habitats and species like sponges, lampshells, and a wide range of fish. They also contain some of the world's biggest populations of black coral trees that can be over 300 years old and are home to brittlestars that can only live entwined in the branches of these underwater trees.