Mountains to Sea Conservation Trust (MTSCT) is scaling up their collaborative ‘Whitebait Connection’ work in Northland locating, protecting, and enhancing īnanga spawning habitat. The Northland Īnanga Spawning Habitat Restoration Project (NĪSHRP) is receiving $1.2m over 3 years from the Ministry for the Environment’s Freshwater Improvement Fund, the Department of Conservation (DOC), Fonterra, and Foundation North. The project is also being supported by Ngāti Manu – Kāretu Marae, Whirinaki Trust, Patuharakeke Te Iwi Trust, NZ Landcare Trust, Northland Regional Council (NRC), NorthTec, Reconnecting Northland, Hokianga Harbour Care, Kaitiaki Whangaroa, landowners, schools, kura, and several other community catchment groups.
Adult īnanga are the smallest of all the whitebait species, usually reaching 110 mm. Unlike the other members of the whitebait family, īnanga cannot climb. Instead, they overcome small barriers by burst-swimming. This lack of climbing ability means these fish are a lowland coastal species. The whitebait fishery in New Zealand rivers is based on the juvenile, upstream migrant phase of five species of galaxiid fish. The main species is īnanga and its proportion in whitebaiters’ catches is typically 70 to 100% of the total catch. Unfortunately, the conservation status of īnanga is ‘At Risk - Declining’ due to habitat disturbance and modification. Drainage of swamps and wetlands has reduced vast areas of adult habitat with approximately 97% of Northland’s original wetlands lost to development.
Similarly, the available spawning habitat for this species has also decreased significantly across the country. Loss of lowland spawning areas is of concern, particularly as successful spawning is such an important life-stage component for the continued survival of this species. Protection of spawning sites is therefore essential to ensure the continued survival of īnanga who spawn in the streamside grasses submerged by high tides during the new and full moon phases where the saltwater meets freshwater, the area is known as the ‘saltwater wedge’. Īnanga eggs remain in the riparian vegetation for approximately one month after laying until inundated by the following high tide. Changes in land use in these spatially limited places on the river make them particularly vulnerable to failed spawning. And, as īnanga are an annular species, where most die after one year, any year where spawning is unsuccessful will have knock on effects in successive years. The value of these critical habitats is now being recognised, leading to protection and restoration initiatives.
In 2013, Whitebait Connection (WBC) started to focus on the importance of īnanga spawning sites in Northland. At that time, the Department of Conservation (DOC) had only confirmed one īnanga spawning site across the whole of Te Tai Tokerau/Northland. In 2014, WBC partnered with NRC, Ngā Whenua Rahui, and Whangārei based hapū Patuharakeke to host a wānanga at Takahiwai, Whangārei. The wānanga was aimed at learning about īnanga spawning survey methodology from expert Dr. Michael Hickford from the University of Canterbury. Since then, WBC has identified īnanga spawning sites across dozens of waterways in Northland, and has created the ‘National Īnanga Spawning Programme’ which shares the knowledge gained, across an even wider audience. This programme has now involved thousands of people around NZ and helped to identify and protect nearly 100 new spawning sites the length and breadth of the country. This includes a 5-year Auckland regional īnanga spawning habitat restoration project funded by Auckland Council.
Now in its second year, Project Manager Nicholas Naysmith says,
“Project outcomes so far include; the training of 55 field staff from MTSCT, mana whenua, DOC, NRC, and community groups in the finding, protection, and restoration of īnanga spawning zones, the engagement of over 254 community members in restoration efforts, delivery of 4 school programmes in our priority catchments, searching for eggs across 22 hectares of spawning habitat with the quantification of nearly five million īnanga eggs, the mapping of 67 potential spawning zones on 8 rivers, installation of fencing along 1300 m to exclude stock from spawning zones, pest plant removal across 10,000 m2 of land, pest animal control across 2.5 ha of spawning zones on the Ruakākā river, and the planting of nearly 9000 natives along spawning zones and riparian margins”
Planting riparian margins greatly benefits the overall health of rivers, not just the īnanga spawning sites. Native trees, shrubs, and grasses stabilise banks, reduce runoff and capture sediments, capture and utilise fertilisers before they reach the river, provide shade that lowers water temperature, add diversity to the area, and attract birds and insects. The team have also removed acres of pest weeds, and trapped hundreds of pest mammals, including rats and mice. Both these species are known to predate on īnanga eggs, so removing them from the environment will aid in spawning success.
MTSCT’s Poutokomanawa/Co-Director – Freshwater Lead, Kim Jones says
“Our knowledge base in Northland is still not where it needs to be to ensure this species has the habitat it needs to sustain a viable population. The data that WBC has collected is currently the only data the region has on the location of these critical life-stage specific habitats. If we do not accelerate the identification and restoration of these important areas alongside the community and partners, we risk losing a taonga species from Northland. We also know that restoration for īnanga is good for water quality, biodiversity, and building resilience within our waterways and communities, so it’s a win for the big picture too”
Much of the success of the project comes from the collaborative efforts of landowners and hapū groups that WBC works alongside. Ben Herbert (Fonterra Sustainable Dairy Advisor), and Nic Naysmith (NĪSHRP Manager) recently interviewed dairy farmer Jarrod Halse about his involvement in the project over the last few years. It became abundantly clear that Jarrod has enjoyed being part of the project.
“I have found it insightful learning about the river, learning how we can do better. It’s been great bringing the school kids on-farm and giving them an appreciation for the river. It puts the river front of mind…and you get focussed on looking after our environment. Once you start and then you actually learn, you get quite passionate about it. I talk to others about it as well, and they're listening and learning too. A lot of people are asking me how to get involved, and what they can do (on their farms). Don't be shy, it's a good experience and you can learn a lot, and you know why not? If you can devote a bit of time to it you're gonna get a lot out of it.”
And asked if the project has benefited his farm directly, Jarrod had this to say;
“The planting has been great. We will be getting some shade for the animals in the future, and controlling runoff when fertilising. Moving the fences back didn't change the paddock size much at all, and it was land that was obviously too steep to plant (in grass), so it made sense to come back a bit more from the edge of the bank. Any erosion from the river, you haven't got to re-fence or anything, just plant the trees, you shouldn't have to touch it again, that's the plan”
Nic asked Jarrod what he had learned about īnanga so far during the project. Jarrod had this to say
“I didn't realise where they spawn was just a tiny area where you've got your freshwater and saltwater meeting, that these places are very special, and that they are quite endangered. We take it for granted that you see them (swimming) around, and people can just collect them. There are no limits for the amount of whitebait you can harvest”.
The funding boost will enable capacity and capability development for local communities. This will help to fill current knowledge gaps and increase effective management of freshwater and riparian habitats for the protection of īnanga. Data captured in this research project will be used to prioritise habitat restoration that builds resiliency for the effects brought on by climate change, and to motivate and implement actions that will improve water quality in the long run.
If you wish to become involved in the project in any way, or would like advice about how to find and restore an īnanga spawning zone on your property please get in touch.
Nic Naysmith
Manager of the Northland Īnanga Spawning Habitat Restoration Project nicholas@mountainstosea.org.nz
Written by Nicholas Naysmith - edited by Lorna Doogan.
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