FRESHWATER FISH of NZ
Science Learning Hub
Last updated 9 weeks ago
Zealandia reservoir to be drained to remove a tonne of pesky perch –STUFF March 2021
The lower reservoir at Zealandia is being drained this month to remove around a tonne of unwanted fish, which are eating native species and throwing the ecosystem off balance. Perch were introduced to Roto Kawau, the lower part of an existing man-made reservoir, more 140 years ago, by people wanting to create fishing opportunities. They preyed on native fish, and altered the food chain by consuming invertebrates (zooplankton), which normally eat algae (a phytoplankton called cyanobacteria),...
Urban eels sanctuary draws in more tuna to the Manawatū awa
The return of tuna to the Manawatū awa has been a great success, but it’s only the beginning, organisers say. Eel, known as tuna in te reo, have grown significantly in numbers at the Urban Eels Sanctuary on the He Ara Kōtahi pathway. Rangitāne in partnership with the Palmerston North City Council released three tuna into the Turitea Stream in July last year.
New technology helps find koi carp
The HBRC is pleased that a new environmental DNA technology has helped confirm a suspected presence of the invasive koi carp in a farm pond in Hawke’s Bay. A tip off from a farm manager, followed by a eDNA sample has resulted in a process to remove two fish that had been in the pond for some time. Freshwater ecologist Daniel Fake says koi carp have wreaked havoc in the Waikato, Auckland and Northland where they have proliferated, and the council doesn’t want that to happen in Hawke’s Bay.
Hauraki Plains' drains of death
A lethal combination of heat, silted-up floodgates and degraded waterways has led to a deadly outbreak of botulism and a suspected toxic algal bloom Parts of the Hauraki Plains have become killing fields for ducks and eels as summer heat exacerbates existing habitat problems. There’s been a triple whammy of death. Algal blooms have turned water into a “pea soup" and a hot summer has seen unshaded drains reach 29°C. Eels trying to escape the adverse conditions have been trapped ...
Should we stop whitebaiting?
By Stella McQueen* A version of this story first appeared in Forest & Bird magazine in Spring 2016. Help whitebait You can make a submission to Department of Conservation supporting better whitebait rules before 2 March 2020. Whitebait season is again upon us, and many are wondering if it will be a bumper year or a fizzer. The size of the catch depends on a mysterious combination of the weather now, the weather a few months ago, ocean currents, and the lure of supply and demand.
Scientists help lamprey to spread the love
Contraptions that resemble upside-down kitchen sinks have been placed in the Waikawa River in Southland to attract a notoriously elusive native fish species. NIWA scientists have dubbed these structures “lamprey love lofts” and the hope is that lamprey will use them for spawning. The pouched lamprey, also known as kanakana and piharau, is an important taonga species for Māori. Once prolific nationwide, there are still strong populations in the South Island but they are becoming rarer ...
Closure on a fishy cold case
A PhD student has possibly cracked the case on one of New Zealand’s fish mysteries and his work could shed light on risks facing longfin eels. It’s been an enduring whodunnit. Who and what killed New Zealand’s grayling? The freshwater fish, about the size of a small trout was once so abundant its babies were shovelled onto market gardens as fertiliser. It also was said to make a fine meal. The widespread, and reportedly beautiful fish disappeared shortly after European settlement.
'Fish ear bones are like a diary'
'Fish ear bones are like a diary' - RNZ PODCAST NIWA freshwater ecologist Dr Eimear Egan describes herself as an “otolith nerd”, and she has been gleaning insights into past climates from historic collections of eel and flounder ear bones collected from around New Zealand.
The Whitebait Wriggle by Amber McEwan
The Whitebait Wriggle by Amber McEwan, illustrated by Stephanie Bowman Ian, Billy and Ginny, and Keri and Sheri have just set off on the journey of a lifetime. Tiny, little whitebait swimming all the way from the oceans around New Zealand to our rivers and streams.
Three of four NZ fish 'staring extinction in the face' - NZ HEARLD ARTICLE 10 Sept 2018. New Zealand's freshwater fish species are in peril - and especially in our pastoral countryside, researchers say. In a study published today, Victoria University's Dr Mike Joy and colleagues compared land use changes and more than 20,000 freshwater fish records since 1970.
BAIT! - NZ GEO ARTICLE by KERI HULME On the West Coast, catching whitebait isn’t a hobby, or a sport, or even a business: it’s a religion. There’s something about these tiny, translucent slivers of life that transforms fishers into fanatics, and draws them each spring to where the rivers meet the sea.
Blood suckers - NZ GEO ARTICLE Lampreys have done without bones—even jaws—for 360 million years, making do instead with a mouthful of rasps designed for shredding. But those teeth are no match for a new and invisible enemy. Are pesticides killing the lampreys? Scientists are scrambling to find out.
Te noho mōrearea i ngā whakataunga tiaki taiao
Ngā ika taketake wai māori o Aotearoa — TEACHING RESOURCE Neke atu i te 54 ngā momo ika taketake kei ngā manga, ngā roto, ngā awa me ngā repo o Aotearoa – he ika ririki, he kōpūtea, he tuna, he piharau, he mohoao, he papangoko, he paraki me te kanae ētahi o ngā ika. Arā tōna 15 ngā momo ika ririki kātahi anō ka kitea i Te Waipounamu, engari kāore anō kia whakaingoatia.
Kaiwharawhara Stream, ca 1885
Planning for change — TEACHING RESOURCE New Zealand has 425,000 kilometres of rivers and streams to look after. Catchment groups are being formed around the country to look after our waterways from the mountains to the sea. These community and citizen science groups are a positive way for schools and students to get some hands-on learning while giving back to their own communities. In some cases, schools have also driven the formation of such groups.
Freshwater ecosystem — STUDENT ACTIVITY New Zealand’s streams, lakes, rivers and wetlands support around 54 species of native fish including galaxiids, bullies, eels, lamprey, black flounder, torrentfish, smelt and mullet – and these are just the ones we know of that have been identified and classified! This ecosystem also provides a home for many other species, including ducks, insects and kōura. In this activity, students use resource materials to identify the features of a variety...
Longfin eel – on a path to extinction? — ARTICLE In mid-April 2013, the Parliamentary Commissioner for the Environment (PCE) Dr Jan Wright launched a report On a pathway to extinction? An investigation into the status and management of the longfin eel. The report warns New Zealand that we need to stop commercial fishing of our native longfin eels (Anguilla dieffenbachia) or the species will face extinction.