Protecting the white gold: Surveys find whitebait spawning in Whakaraupō streams
Environment Canterbury media release: 15th September 2025
Whitebait may be a seasonal delicacy for many — with the season now underway — but behind the scenes, efforts are being made to help ensure these taonga (treasured) species are healthy for generations to come.
A recent collaborative survey in Whakaraupō/ Lyttelton Harbour has uncovered promising signs of īnanga (īnaka) spawning in local streams — an encouraging step towards protecting the most common and smallest of Aotearoa’s five whitebait species.
The discovery of their tiny eggs, just 1mm in diameter, required sharp eyes and careful searching, highlighting the delicate nature of their lifecycle.
Martin Rutledge, our central team biodiversity advisor, Nadia Green, Ngāti Wheke (Rāpaki) Kaimahi a Taiao, and Brittany Earl from Department of Conservation (DOC), worked together to coordinate the survey.
Īnaka numbers were assessed in the Allandale, Waiake, Te Wharau/ Charteris Bay, and Pūrau streams in Whakaraupō.
Small streams, big impact
Martin said the team’s survey found 24 egg patches in Allandale and Waiake streams with a total number of about 700 eggs, which were mostly located in the bases of tall grasses like tall fescue.
“While these aren’t big numbers of eggs, it's good to know that the habitats are still productive and we can see opportunities to enhance them, for example by recontouring steep banks to a more gentle profile, excluding stock, riparian planting and control of weeds,” Martin said.
“These streams are small in terms of the spawning habitat they can support, but every successfully-hatched whitebait egg contributes to sustaining the population.”
Why this work is important
Īnaka have a species threat ranking of ‘at risk - declining’, so conserving the species and protecting their spawning habitat is very important. They spawn in streamside vegetation during autumn spring tide cycles. These spawning areas are critical to the survival of the species.
Learn more about īnaka.
While their size is not as big as the other species, īnaka numbers are much higher and make up about 85 per cent of total whitebait catch.
Adult īnaka reach about 100mm long, while adults of the other whitebait species are much bigger such as:
Adult giant kōkopu often reach 400mm or more and are colourfully patterned.
Nadia said, “it was great to find my first īnaka eggs and see schools of hundreds of mature fish in Te Wharau and Pūrau streams, but frustratingly we only found one small patch of eggs in Te Wharau and none in Pūrau stream.”
Īnaka egg surveys return in autumn 2026
The team will be back again to look for īnaka eggs in autumn 2026.
Besides working on īnaka, Brittany also studies a range of other fish species.
“I’m looking forward to surveying for spawning again next autumn and carrying on with survey work in Whakaraupō and elsewhere on Banks Peninsula, and especially for another of my target species: kanakana/ lamprey. This is a threatened, very rarely seen eel-like fish whose adults suck onto and feed on marine fish and then return to streams to spawn. It would be awesome to find kanakana in Whakaraupō,” she said.
Learn more about kanakana/ lamprey.
Kaiārahi Taiao Paul Dahl said Te Hapū o Ngāti Wheke has mana whenua (authority over the land) and mana moana (authority over the water) at Whakaraupō.
“It's very positive to be doing mahi with Environment Canterbury and DOC to extend our knowledge of freshwater species, with our common goal to protect and improve their habitats,” Paul said.
Find out more about Te Hapū o Ngāti Wheke.
Make sure you're ready for the season!
The whitebait fishing season runs from 1st September to 30th October nationwide, except for the Chatham Islands, where the season runs from 1st December to the last day of February.
Find out more about regulations around whitebait fishing in Canterbury.
DOC is responsible for managing whitebait fisheries and we manage the licensing of what are commonly known as "stands". A stand is any structure authorised to fish for whitebait under the Resource Management Act (RMA) 1991.