Freeing up fish passage

The unique and unusual kanakana, an ancient, boneless eel-like fish, with a sucker mouth, horny teeth and a rasping tongue, is one of many native fish species in need of increased protection measures in southern waterways. About 76% of our freshwater fish are either threatened with, or at risk of, extinction.

In July last year, Environment Southland was awarded $385,000 from the Government’s Jobs for Nature programme to identify, prioritise and remediate fish barriers in Southland’s rivers and streams. Environment Southland will contribute $115,000 from existing biodiversity budgets over five years to the project.

Jane, who has a strong background in ecology and traditional ecological knowledge research, is working with Te Ao Marama Incorporated(TAMI), the environmental arm of Ngāi Tahu ki Murihiku. TAMI is a key partner in the fish passage project.

“Native fish species are connected to us in so many ways. They are part of our identity. It’s actually about who we are.”

Just look at whitebaiting, and its importance to many people in the south, she says.

Through her company, Kitson Consulting, Jane works at the interface of mātauranga Māori and science, assisting organisations to develop and apply enduring environmental solutions.

Mātauranga Māori is an holistic perspective encompassing all aspects of knowledge and seeks to understand the relationships between all component parts and their interconnections to gain an understanding of the whole system.

Jane says it’s important to reiterate that although mātauranga has been around for a very long time, it is also a dynamic and evolving knowledge system based on its own principles and frameworks.

The fish passage project is a really positive step because there are some easy wins that can be achieved with the identification, prioritisation and implementation of fish passage around Southland.

She says people are adapting their thinking around human interactions with our environment, and this increased understanding bodes well for the challenges we face as a community.

Environment Southland biosecurity and biodiversity manager Ali Meade says the project has a target of restoring fish passage by removing 250 barriers in streams and tributaries across the region by mid 2025.

It aims to retrofit fish ladders, baffles, spat rope to culverts, or use rocks and pools to raise water levels, to remove in-stream barriers to restore fish passage and increase the sustainability of indigenous fish populations.

“With more passages, fish will be able to move freely between inland streams and the sea, which will help boost numbers of these amazing native species,” says Ali.

Manmade structures in streams such as culverts can disrupt this passage and create a barrier for fish travelling between inland streams and coastal waterways.

“Between 2015 and 2017 our science team mapped over 80 fish barriers within the Southland roading network, and we know that there are also a number of barriers to fish movement on private land in Southland.”

Fish passage is mandatory under the new freshwater regulations. The council is working closely with Te Ao Marama to align both iwi and council priority areas, and is also working closely with landowners and catchment groups within the programme.

Identifying the right spots for fish passages, and prioritising installation points, including linking passages, were important initial aspects of the work, Ali says.

Native fish species supported through the work include kanakana, ōkopu, īnanga, common bully, redfin bully, bluegill bully, torrentfish, banded Kokopu, kōaro, and longfin eel and shortfin eel.

Ali says solutions will be tailored to each individual barrier taking into account the native species, stream connections, ecosystem health, and impacts of exotic species.

You can read the full Envirosouth magazine as a PDF online here.