Threats to Galaxiids
A list of threats:
2. Destruction of spawning sites
4. Water take
5. Modification of streams
(e.g. removal of aquatic macrophytes)
6. Dams (more critical for migratory galaxiids)
7. Gold mining
One of the main troubles for Otago galaxiids is trout. They are almost never found together in streams because for more than a century, trout has out-competed native fish in competitions for food or habitat (or simply by eating them).
Galaxiids are thriving in small streams where trout have not spread or cannot survive. Unfortunately, many of those streams often have poor water quality or low water levels… probably galaxiids don’t like them much either.
Another difficulty for lowland galaxiids is water uptake for irrigation. Oddly enough, it is simultaneously a problem and salvation for the native fish of the area. Higher water flow would provide better living conditions and more food; on the other hand, low flow separates sections of the stream, making passage of trout to some areas impossible.
Native fish habitat is shrinking
a) as wetlands are drained
b) streamside vegetation is removed
c) predation & competition from introduced trout continues