Tyre Gulley is a small, unassuming, tributary of the Cardrona River, located near the summit of the Crown Range Road. This stream and its catchment is home to one of Aotearoa’s most endangered freshwater fishes, the Clutha flathead.
Clutha flatheads, classified as ‘Nationally Critical’, are one of our galxaiids. Members of an ancient, scaleless fish family called Galaxiidae – for the galaxy-like gold flecks and patterns on their backs.
Living their entire life in the stream or river where they hatched, millennia of isolation mean that they have evolved into many different species (as many as 25), some found in one or two rivers. All have a threatened or at risk conservation status.
One of the biggest threats to flatheads and other galaxiids are trout. They compete for the same food and even eat the galaxiids themselves. The Taking Care of Tyre Gulley project has successfully removed trout from Tyre Gully upstream of a temporary fish barrier, which has been improved and made permanent.
For months, no adult trout have been found and juvenile galaxias have reoccupied the habitat formerly occupied by trout. eDNA testing has confirmed that trout are no longer present in Tyre Gully.
The team is now working on opportunities to progressively extend the populations of Clutha flathead galaxias further down the Cardrona Valley, on both public and private land. They are also undertaking research to monitor the population, and planning planting to revitalise the riparian strip.