#1 Our freshwater fish LEARN ABOUT OUR UNIQUE NATIVE FISH, WHERE THEY LIVE AND Giant kokopu. Photo: Stephen Moore, WHAT YOU CAN DO TO HELP PROTECT THEM AND THEIR HABITAT. Landcare Research Something in the water… Meet the locals! Picture a freshwater fish - is the first one that comes to Many of our native fish are seldom seen because they are mind an eel or trout? New Zealand’s streams, lakes, secretive, small, camouflaged, live in remote areas, or are rivers and wetlands support around 50 species of native nocturnal, hiding under rocks and overhanging vegetation fish – galaxiids, bullies, eels, lamprey, black flounder, during the day. Our native fish are also rare – half are torrentfish, smelt and mullet to name a few. Add to this threatened with extinction, with one already extinct – the around 22 species of exotic fish. With this many species, grayling, last seen in the 1920’s. our freshwaters should be packed with all sorts of fish, right? Read on to find out what the story is. If they don’t end up in a frying pan, some of these tiny fish can migrate over 100 km from the sea upstream. Photo: Peter Hamill, Marlborough District Council The Galaxiids: Aquatic all-stars Galaxiids are New Zealand’s largest group of freshwater There’s more to whitebait than fritters! fish with 29 species including inanga, kokopu, koaro Whitebait are actually 5 species of galaxiid. As and mudfish. The name galaxiid refers to the clusters “diadromous” fish, they spend part of their life in the of golden or silvery star-like patterns on their scale-less ocean and part in freshwater. Adults gather from autumn bodies - perfect camouflage in the dappled light of to winter to breed. Some species like banded kokopu the small forest streams they tend to favour. They are lay their eggs in amongst leaf litter in forested streams also found in swamps, drains and larger waterways. during high flows. Other species migrate downstream Many galaxiids, particularly koaro, are great climbers, to lay their eggs and one species, the inanga gathers in able to scale waterfalls helped by ridges on their fins. estuaries to spawn on king tides. Their eggs stick to damp Invertebrates, both aquatic species like midge, mayfly grasses, rushes, sedges and flax on the river banks, and and mosquito larvae, and those that fall into the water, hatch around two weeks later on the next set of high are an important part of their diet. tides. Floods and ebbing tides induce the larvae to hatch Mudfish: summer sleepers before being carried by the current out to sea where they Mudfish have a bizarre ability to live out of water in tree spend four to six months feeding on microscopic plankton. root hollows and damp leaf litter for weeks at a time They return to freshwater between early spring and early during dry periods. They are able to do this by wriggling summer, swimming upstream together as whitebait. their cigar-shaped bodies into tiny crevices, where they semi-hibernate (aestivate) by ‘breathing’ through their The traditional kiwi pastime of whitebaiting is under moist skin. This means that they can survive in seasonally threat! The long-term survival of our native fish is uncertain dry waterways, drains, pools and swamps. All 5 species because their habitat is still being destroyed by wetland of mudfish are considered highly threatened due to drainage, pollution, vegetation clearance, stock habitat loss. damage, over-fishing and continued commercialisation. Barriers in waterways such as culverts hinder their Despite their name, mudfish actually require clean water, migration, and introduced fish such as trout prey on them. and are a good indicator of a healthy environment. Photo: Stephen Moore, Landcare Research Eels: Slippery Introducing the exotics characters In the late 19th century early settlers introduced trout and salmon for sport Three eel species are present in New and food. So treasured are these Zealand; shortfin, longfinand the two game fish that their habitats Australian longfin, or spotted eel, Bullies: tough stuff! get special protection under the thought to have arrived of its own There are 7 species of native bully. Resource Management Act. Char, accord as recently as 25 years ago. Unlike the galaxiids they have coped tench, rudd and perch are also well with humans, remaining fairly fished for. Rudd, though a sportsfish The longfin inhabits all types of water widespread and abundant, with only in the Auckland/Waikato region, is from tiny streams to the largest rivers, one species regarded as threatened. regarded as a pest elsewhere. A Fish coastal and inland lakes, brackish They are “generalists”, occupying all and Game licence is required to fish (semi-salty) estuaries and lagoons. types of aquatic habitat and feeding for these species. Shortfins however prefer warmer on a wide range of food. brackish waters, coastal lakes and lowland lakes. Pets or pests? Many aquaria and pond fish have Redfin bully. Photo: Peter Hamill, Considered a threatened species, been released into waterways, Marlborough District Council longfin catch limits have recently becoming major pests. They’ve been reduced and a maximum size rapidly colonised areas, in some limit applied to protect the large places building up huge populations. mature females. Exotic fish threaten the survival of You can help our native native fish: Like some galaxiids, eels also make the arduous journey downstream fish survive and thrive! • koi carp uproot native aquatic plants, stir up sediment and out to sea to complete their • Plant riverbanks with natives life-cycle. • catfish stir up sediment, eat • Install “fish-friendly” culverts native plants, snails and fish • Fence stock out of waterways NATIONAL TREASURES • gambusia, (“mosquitofish”), EELS (TUNA) ARE SUCH AN • Never tip pollutants down drains tench, rudd, perch and goldfish eat native insects, plants and fish, IMPORTANT RESOURCE FOR MAORI • Leave stable wood debris in denying our native fish their food THAT IN THE PAST BATTLES WERE streams for habitat FOUGHT OVER THEM. TUNA WERE supply CAUGHT USING WOVEN POTS • Take only enough eels and (HINAKI), STREAM FENCES (PA TUNA), whitebait you need for a feed Stop the spread SPEARS (MATARAU), NETS (KORAPA), • Never release or transfer live exotic • Never, ever release unwanted BAITED LINES (TOI), DITCHES (KOUMU) fish into native fish habitat OR BARE HANDS. aquarium plants or fish to waterways, or tip down the drain MAORI IDENTIFY MANY MORE • Wash your boat, trailer and fishing VARIETIES THAN THE THREE SPECIES gear carefully after each trip RECOGNISED BY SCIENTISTS, to make sure they are free of WITH OVER 100 LOCAL NAMES weeds, fish and fish eggs before FOR EELS. launching The longfin can grow to 2 m long • It is illegal to release any fish into and live for over 100 years! The a natural watercourse without a record is a 24 kg whopper caught at permit, or to breed or sell pest fish Lake Waihola near Dunedin. Photo: Stephen Moore, Landcare Research If you weighed all of the fish in the Waikato Basin, a staggering 80% would be koi carp. Photo: Nelson Mail Want to know more? Fishy factsheets in this series: #1 Our freshwater fish www.TeAra.govt.nz/en/life-in-fresh-water/4 #2 Stream works for fish www.nzfreshwater.org/ #3 Fixing your stream edges www.mudfish.org.nz/ #4 Native fish in the city www.niwa.co.nz/our-science/freshwater/ #5 Native fish on the farm tools-old/fishatlas/fishfinder #6 Caring for our catchments www.doc.govt.nz/conservation/native- All factsheets can be downloaded from: animals/fish/facts/ www.landcare.org.nz Published by NZ Landcare Trust 2010. Longfin eel Dwarf galaxias Shortjawed kokopu Longfin eel Dwarf galaxias NATIVE Upland stream FISH IN THE LANDSCAPE Hydro lake In a healthy landscape, our Common bully native freshwater fish can be found in all sorts of places… Forested wetland, areas of native forest Redfin bully and small pools Banded kokopu Torrentfish Mid-reach stream – fast flowing but below waterfall/dam Lake with a Mudfish river inflow and drain outlet Drain Banded kokopu Shortfin eel Giant kokopu Common bully Common bully Lowland stream – wide, sluggish Giant bully Giant kokopu Brown mudfish Shortfin eel Grey mullet Digital catchment background image: Phil Jones, Dialogue Design. Photos: Longfin eel, Dwarf galaxias, Koaro, Grey mullet, Smelt, Shortfin eel, Giant bully, Shortjawed kokopu, Redfin bully, Black flounder, Torrent fish. Courtesy of Peter Hamill, Marlborough District Council. Koaro Common bully Redfin bully Banded kokopu Torrent fish Shortjawed kokopu Streams in forest, Longfin eel solid canopy, small rubbly streams Koaro Longfin eel Streams in forest, solid canopy, small rubbly streams Giant kokopu Lowland swamp Mudfish Grey mullet Common bully Giant bully Estuary Inanga Lamprey Smelt Black flounder Giant bully Sea Smelt Inanga Black flounder Lamprey Giant bully Banded kokopu, Common bully, Giant kokopu, Brown mudfish, Inanga, Lamprey. Courtesy of Stephen Moore, Landcare Research. .