New Zealand’s freshwater fish are part of our natural heritage but because so many species are mostly seen only at night, they are not well known. Some species are a traditional food source and an important part of our recreational and commercial fisheries.
Our rivers, lakes and wetlands are home to 20 species of native fish, which makes the freshwater fishery of the region one of the most diverse in New Zealand. At one survey site on the lower reaches of the Onekaka River in Golden Bay, 13 species of fish were found. This is very high for a single site in New Zealand. Most often it is the small to medium-sized creeks that hold the greatest abundance and diversity of fish.
Of the 20 species of native freshwater in the rivers, lakes and wetlands of Tasman District, fifteen need to migrate between freshwater and the sea during their life. Structures such as overhanging culverts, tidal flap gates and dams can block fish access. From assessment completed to date, about 450km of stream was totally inaccessible to fish in 2005. By June 2012 this had reduced to 330km. A further 1000km may be inaccessible to migratory fish at certain flows. It has been estimated that Land drainage, flood protection schemes, and introduced pest fish can also affect our native fish.
Unfortunately over half (11) of our native fish species are classified as "in decline". Even the long fin eel, which is still the most widespread and abundant freshwater fish in New Zealand, is reported as declining, with the most concerning sign being falling recruitment rates of juvenile eels. Some species, like the kōkopu (e.g. giant, short-jaw and banded), kōaro and red-fin bully are very sensitive to stream habitat disturbance such as streamside forest clearance, stream straightening/realignment and stock trampling. Fish surveys in Tasman repeatedly show much higher numbers of these sensitive species in undisturbed streams. Giant kōkopu are now very rare with only 42 sites in official records. These fish generally require wetland-fed streams in lowland areas but about 90% of all lowland wetlands in the district have been drained.
Common Name |
Māori Name |
| Shortfin eel | Hao or Tuna |
| Longfin eel | Kuwharuwharu or Tuna |
| Lamprey | Pirahau or Kanakana |
| Torrentfish | Papamoko |
| Giant Kōkopu | Kōkopu |
| Kōaro | |
| Dwarf galaxias | |
| Banded Kōkopu | Para |
| Īnanga | |
| Short-jaw Kōkopu | |
| Northern flathead galaxias | |
| Brown mudfish | |
| Giant bully | |
| Upland bully | |
| Common bully | Pako |
| Bluegill bully | |
| Redfin bully | |
| Common smelt | Ngaoire |
| Yellow - eyed mullet | Aua |
| Black Flounder | Patiki |
Tasman district is known nationally and internationally for its diverse wild brown trout (Salmo trutta) fishery and excellent angling opportunities. The Motueka River catchment has historically received the most use, at more than 13,000 estimated angler visits per year.
A small rainbow trout fishery exists in the Cobb reservoir and upper Cobb River. Chinook Salmon have been introduced over many years into the Buller, Motueka and Golden Bay catchments but most efforts have failed. However they are found in the lower Tākaka and Te Waikoropupū rivers.
Fish and Game NZ manages and monitors these fisheries. It provides fishing licences and checks anglers comply with the regulations.
Visit the Fish and Game New Zealand website
The Sports Fish and Game Bird Plan for Tasman-Nelson-Marlborough sets out the objectives and methods for managing these fisheries. Council has a key role in managing the habitat of trout and salmon.
Find out when and where to fish for whitebait in New Zealand. The Department of Conservation website has comprehensive information.
Īnanga are the most common native fish species known as whitebait. There are five species of whitebait (or galaxiid fish), the others being banded kōkopu, giant kōkopu, kōaro and shortjaw kōkopu. All of these species are migratory and need to be able to swim upstream to spawn (breed).
In 2012-13, Tasman District Council in association with Department of Conservation and community volunteers, surveyed inanga spawning sites around the region.
Of the 50 sites surveyed, a total of 37 spawning sites were discovered. These sites were predominately found to be on the northern bank of the waterways, however, constant temperature, humidity levels, shading and type of vegetation cover were the most influential factors.
Details about the findings of these surveys are available as a draft report from Tasman District Council.
Contact Tasman District Council's Resource Scientist for a copy of this draft report.
The annual upstream migration of whitebait creates an important recreational and commercial fishery in the district. The juveniles of five species of Galaxias and juvenile smelt make up the whitebait catch, but in most rivers and streams Īnanga is the most abundant species.
Throughout much of New Zealand the īnanga habitat, egg-laying sites as well as juvenile and adult habitat, has been affected by urban and rural development which has contributed to a gradual decline in the size of the whitebait runs.
After migration into fresh water, īnanga grow to maturity in low gradient and low altitude waterways. Providing upstream access is an important means of increasing habitat for adult īnanga as they have little climbing ability.
Īnanga lay their eggs (spawn) amongst at the edge of the stream in long grassy vegetation near estuarine areas, usually near the upper limit of the saltwater wedge associated with high tides. The same spawning sites are used year after year, so it is important that these areas are protected or improved if degraded.
Tasman District Council has carried out fish surveys annually since 2006.
The aim of the surveys is to determine the effect on fish populations with varying habitat condition. This is achieved by comparing the diversity and abundance of freshwater fish in streams of a natural state with those that have been modified in various ways.
The surveys also assess the success or otherwise of stream restoration projects, as well as gather information that can be used to better predict fish distribution in the future.
Tasman District Council monitors freshwater fish in cooperation with Fish and Game NZ and the Department of Conservation. All three organisations share responsibility for monitoring fish populations under a range of legislation and it works out efficiently to work together.
Freshwater fish in wadeable streams are sampled by backpack electric fishing, spotlighting and, in some circumstances, traps or nets. Fish are identified, sized and released. The methods used very rarely harm the fish. Over 30 sites are sampled each year, but only six are sampled on an on-going basis.
Along with the fish surveys an assessment of habitat is also recorded. Several parameters are measured:
Trout populations in the larger rivers are sampled using drift-diving methods. These are carried out annually at a range of sites and organised and managed by Fish and Game NZ.
If you have any further questions, please contact Tasman District Council's Resource Scientist
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