Page 3 – Fish and marine mammals
Over 150 species of fish are known from New Zealand’s fiords. The fish life there is distinctive. One species, the brotula Fiordichthys slartibartfasti, lives only in Fiordland. Except in Doubtful Sound and Milford Sound, where amateur fishing is commonplace, blue cod (Parapercis colias) are so tame that they will swim up to divers. Girdled wrasses (Notolabrus cinctus) may nip the exposed parts of divers – typically their lips. Butterfly perch (Caesioperca lepidoptera), first collected on James Cook’s second voyage to Dusky Sound in 1773, tend to follow divers for a while before losing interest. Such behaviour may lead to a mistaken impression that there is an abundance of fish.
A novel name
The scientific name given to a new species is often taken from the person who discovered it. However, in the case of the brotula fish, Fiordichthys slartibartfasti, scientists had a bit of a laugh. The name doubly celebrates the fiords where these fish live. Fiordicthys means fish of the fiords, and Slartibartfast was a character who designed fiords in Douglas Adams’s 1979 comic novel The hitchhiker’s guide to the galaxy.
Jock Stewart fish (Helicolenus percoides) and scorpion fish (Scorpaena papillosa) tend to sit on the bottom of the fiords or, in the case of scorpion fish, occasionally in trees of black coral. Scorpion fish are well camouflaged, but Jock Stewart fish are easy to see because of their large reflective eyes.
Common triplefin or cockabullies (Forsterygion lapillum) abound, and in the middle and inner fiords they may be found in densities of hundreds per square metre.
The only deep-water fish known to live in the fiords is the elegant wavyline perch (Lepidoperca tasmanica). They normally live around rocky reefs at 150–400 metres, but in the southern fiords they can be found at depths of 6–31 metres.
New Zealand fur seals (Arctocephalus forsteri) are common in the fiords. They breed on offshore islands near fiord entrances, and when juveniles disperse from their colonies it is often to the inner fiords.
Unusually, there is a resident pod of about 60 bottlenose dolphins (Tursiops truncata) in Doubtful Sound. They have been intensively studied, and their seasonal pattern of movement between the Doubtful, Thompson and Bradshaw sounds is well known. Other marine mammals such as elephant seals, leopard seals, orcas and the occasional larger whale are also irregular visitors to the fiords.