Why are īnanga important?
Updated: Aug 15, 2022
There are many critters in the ecosystem of South Titirangi that need protection and support to thrive. A big part of the pest eradication project is to create an environment that sees the return of creatures, or an increase in population.
One of these is the īnanga, a native freshwater fish commonly known as ‘whitebait’ and is the smallest of the five whitebait species. Creating, supporting, and protecting environments where these juvenile fish can thrive is a nationwide project with the Whitebait Connection. We are lucky enough to have a local stream that already has two of the whitebait species (banded kokopu and īnanga), and is of interest with the Whitebait Connection to be monitored checking the health of the stream and available habitat for the fish. Inanga have been spotted living in Paturoa Stream (Titirangi Beach) and STNN are supporting The Whitebait Connection in protecting their potential spawning area.
Īnanga spawn on the spring tide, laying eggs in the submerged vegetation at this tide’s peak. These eggs then develop above the water line before hatching and being swept out to the ocean. Whilst they are above the water line they are especially vulnerable to a number of threats.
Why is īnanga important? īnanga is important as protecting their lifecycle protects the lifecycle of the other whitebait species, many of which are declining or threatened. This is not about creating a whitebait fishery on the Manukau; it is about trying to protect and enhance these species, which are juveniles for many fish species.
What are STNN doing? We know that īnanga are highly vulnerable to predation while they are in their egg/larval form on the riverbanks. So we are planting up these areas to provide some vegetation to create suitable spawning spaces, which will also shade the eggs while they are developing. We are also providing pest reduction around these breeding areas to reduce the number of mice, rats, and possums which could prey on them. Planting around the river edge makes it less likely that people will walk on the edge and trample the eggs.