The underwater environment in the fiords is one of the most intriguing and unique in the world.
This is not only because of the beautiful natural environment and the marine reserves that exist here, but also because of an interesting effect of the high rainfall in the area.
As rainfall drains through the lush forests it becomes stained with tannins until it is the colour of strong tea. This dark freshwater does not mix with the seawater of the fiords but rather it sits on top, limiting the amount of light that reaches into the depths. As a result light sensitive species that normally live at great depths are found much closer to the surface in Fiordland waters. This gives divers the opportunity to see rare species such as the red and black corals at relatively shallow depths.
Milford Sound has a very special underwater environment
Many other animals and organisms call Milford Sound home. Divers have the opportunity to see many other species like crayfish, spiny dogsharks, sea dragons, nudibranch, tube worms, sponges and walls of yellow zooanthides. The New Zealand fur seal inhabits Milford Sound and are often playful and curious to see where the divers bubbles come from.