Rare mudfish a welcome find in Koputaroa wetlands

A rare mudfish, known locally as hauhau, was a welcome find for KiwiRail’s Regional Rail Team working to clear culverts in Koputaroa, near Palmerston North last month.   

It was discovered as part of early preparations for planned upgrades to the Manawatu line.   

A ‘fish rescue and relocation operation’ was carried out under the watchful eye of Wildlands Ecologists Tessa Roberts and Lilly Tidwell. 

Ms Roberts says the Brown Mudfish, or Neochanna apoda is only found in high-quality wetlands so KiwiRail’s team was on the lookout for the rare species. 

“Koputaroa Scientific Reserve is considered a stronghold for the Brown Mudfish. That’s why we took good care to isolate the impacted area and remove as many fish as possible from around the culverts prior to works starting.  

Brown Mudfish grow to around 10cm long and have an eel-like appearance, with thick, slippery skin rather than scales. They have a conservation status of At Risk–Declining under the NZ Threat Classification System. This is mainly because they live in wetlands, many of which have been drained and converted to other land uses. 

Along with the mudfish, there was a healthy presence of tuna (eel), kōkopu (adult whitebait) and toitoi (common bully), with a total of 36 fish relocated from the three culverts. 

KiwiRail has begun work in Koputaroa and Tokomaru as part of getting the Manawatū Line ready for faster and more frequent services later this decade.  

“We are grateful to the landowners who were happy for us to access culverts via private land. Thanks also to the Wildlands ecologists, and local contractors Digger Services, JBs, and Tatana Contracting who helped us bring the culverts back to their former glory,” says KiwiRail Project Manager Ollie Smith.    

“Looking after the wetlands while working in the area is important to us because we know how important it is to the ecology and community.” 

From 2029/30 people commuting between Palmerston North and Wellington will be travelling on Greater Wellington’s new Tūhono battery electric trains, and services will increase to four return trips per weekday plus two on the weekend.