Fish & Game, a New Zealand organization, has carried out an electric fishing research program that has revealed the effects of barriers on fish passage on native species and trout in Taranaki. Additionally, it has monitored a recovering population of kōaro and eel in Nelson/Marlborough. The Fish & Game teams in regions such as North Canterbury, West Coast, Central South Island, Taranaki, Wellington, and Otago are using a low-voltage, high-current charge-emitting pole to sweep rivers and streams. This method temporarily stuns fish that are then scooped up in a net, weighed, measured, identified, and returned to the water.
The program helps Fish & Game monitor the populations of trout and salmon and record native freshwater fish such as bullies, eels, kokopu, lamprey, koura, torrent fish, various galaxiids, and kōaro. Additionally, it helps them note the condition of waterways, barriers to fish movement, and macroinvertebrates. The data is entered into NIWA’s New Zealand Freshwater Fish Database and is used by other freshwater scientists to inform both regional and national policies.
Electric fishing surveys in Taranaki are monitoring the effects of barriers on fish passage for native species and trout and have identified a decline in water and habitat quality down the length of ringplain catchments. In Nelson and Marlborough, Fish & Game staff, along with DOC staff, are monitoring a recovering kōaro and eel population following the devastation caused by Cyclone Gita in 2018. They have also found that increased floods generated by climate change pose just as much, if not more, risk to native fish populations as they do to trout.
According to Corina Jordan, the chief executive of Fish & Game, "Electric fishing is helping to protect New Zealand’s freshwater fish and rivers. It may sound unusual, but it’s an effective way to keep watch on the state of our fish species, including indigenous populations, and the places they live. These surveys support other research that show native fish populations, as with juvenile trout, are at risk from the increased frequency and size of flooding." The Fish & Game staff also connect with local communities, landowners, and partners through the program.
In Hawke’s Bay, Fish & Game staff are planning to resume electric fishing in small streams in partnership with other local agencies and iwi, which was halted due to Cyclone Gabrielle. Under the Resource Management Act, the management of physical resources must protect the habitat of trout and salmon. Fish & Game mostly uses electric fishing to confirm the presence of juvenile trout, a sign of successful spawning. By observing the presence of trout, Fish & Game can advocate for that habitat, which benefits all aquatic life, including native and valued introduced species. The organization also uses electric fishing to educate school and catchment groups about stream habitat and health. Additionally, they share data with agencies such as the Department of Conservation for resource consents and partner with universities on electric fishing monitoring projects. Jordan stated, "As river guardians, Fish & Game has been gathering and sharing data for over 30 years and will continue monitoring in the future for the benefit of all freshwater fish species."
Images courtesy of Fish & Game NZ