e3Scientific undertake freshwater ecological surveys in the Waikato

Client: Waikato Regional Council 

In 2024 Waikato Regional Council (WRC) commissioned e3Scientific to complete two separate freshwater ecological field surveys to support habitat restoration initiatives and to assess fish-friendly pumpstation effectiveness.  

e3Scientific provided a detailed assessment of benthic habitats and species present within stream reaches through a combination of electric fishing, overnight netting and macroinvertebrate sampling. Field measurements included fish/eel lengths as well as water quality measurements, and habitat characterisation at sampling locations.  

Collated reporting information outlining research findings was provided to WRC within days. e3s identified substantial shortfin eel (Anguilla australis) presence at the pumpstation location, with over 171 individuals measured, ranging from 230 mm to 900 mm. Various exotic species identified include goldfish (Carassius auratus), mosquito fish (Gambusia spp.) and catfish (Ameiurus nebulosus), with koi carp also observed. At the restoration sites, the At-Risk Declining longfin eel (Anguilla dieffenbachii) was found to be in high abundance, along with scattered observations of the shortfin eel; however no other fish species were observed.  

The information provided to WRC allows for informed decision making and a better understanding of these freshwater ecosystems, both at present and in the future.  

Scott Fellers

Senior Environmental Scientist (Christchurch Office)

Waka-Nathan Miller

Scientific Diver, Equipment/Field Technician - Marine and Freshwater Ecology (Invercargill Office)

Mark Hamer

Senior Freshwater Ecologist

Natasha West

Environmental Scientist (Arrowtown Office)

Trudy Anderson

Senior Environmental Scientist (Arrowtown Office)

Brandon Doheny

Freshwater & Marine Ecologist

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