Marine mammals and fish in Abel Tasman National Park
New Zealand Fur Seal/Kekeno
New Zealand Fur Seal are the most common seals in New Zealand waters.They are very good swimmers and weaned pups will turn up almost anywhere around New Zealand. A Fur Seal pup tagged on the west coast of South Island has even been recorded in Australia. On land they sometimes become disoriented and have been found in unusual places such as back-yards, drains and streets.
Common dolphins found in New Zealand waters belong to the species now known as the short-beaked common dolphin. The colouration of this dolphin is very distinctive with a criss-cross or hour-glass type pattern centred on the flanks. Colours include purplish black, grey, white and yellowish tan. The dorsal fin is high with a concave hind edge. The head is low and smooth-sloping.
The world’s smallest penguin, little penguin (also known as little blue penguin) stand just over 25 cm and weigh around 1 kg. The plumage is slate-blue with a bright white belly. They are found on most of New Zealand’s coastline and in southern Australia.
They spend much of their time at sea hunting small fish, crustaceans and squid. Like all penguins they cannot fly, but their paddle-like flippers are excellent for ‘flying’ through the water.Little penguins forage for food up to 25 km offshore and 70 km from the colony.They can reach speeds of up to 6 kph underwater. Little penguins only come ashore under the cover of darkness and live underground in burrows, natural holes, or under human structures or buildings.
Whitebait – migratory galaxiids
The small fish caught each spring by whitebaiters all around the country are actually the juveniles of five species of fish.They are banded kokopu, giant kokopu, inanga, koaro and shortjawed kokopu.
These five are part of a group of fish called galaxiids (so called because of the patterns of their skin which look like a galaxy of stars) of which there are 20 species, the rest of which don’t migrate.
Those that escape the whitebait net grow into silvery, slender adults (about 9 cm long). They spawn in streamside vegetation, even rank exotic grasses are suitable.
Adult banded kokopu have numerous pale stripes across the body and can grow up to 26 cm long. They are good climbers and make their way upstream until they find small forest streams with plenty of cover and shade.
The giant kokopu is a threatened native fish. It is secretive and loves having plenty of cover to hide under, preferring gently flowing overgrown streams, swampy lagoons and lake edges.
Inanga are found in lowland slow-moving streams. They do not climb waterfalls or swim up steep gradients. Like other members of the whitebait family they have gold flecky skin but no scales.
Koaro are spectacular climbers and use their flattened fins to scramble up waterfalls in order to reach shady bouldery forest streams. Koaro have a distinctive greenish-brown patterning and commonly grow to a length of an adult handspan (16-18cm) although some have been found up to 30 cm long.
The shortjawed kokopu is the kiwi of the water world – secretive, nocturnal and threatened. It climbs upstreams in search of shady places with lots of cover such as logs, large boulders and undercut banks.
New Zealand longfin eel
Longfin eels can be found throughout New Zealand. They live mainly in rivers and inland lakes but can be found in almost all types of waters, usually well inland from the coast.
They are legendary climbers and have made their way well inland in most river systems, even those with natural barriers. Elvers (young eels) swimming up river will climb waterfalls and even dams by leaving the water and wriggling over damp areas. It is not unheard of for an eel to climb a waterfall of up to 20 metres.
When eels begin life, they are a tiny one millimetre in length. During their life, they can grow up to two metres long.
Compared with many other fish, eels are slow growing – a longfin may grow only between 15-25mm a year. They can also live for many years. Large longfins have been estimated to be at least 60 years old.
The biggest eels are usually old females that have been slow to reach sexual maturity and, for reasons that are not yet understood, have not migrated to sea to breed.
The information above is from Department of Conservation. Please check their website for more details.