I was reminded this week that trout in New Zealand rivers are introduced predators and that this is not good for some native fish.
I was up in the mountains at Craigieburn Forest Park on Thursday (scoping out a new university ecology field trip). One of our team thought she saw a trout in Cave Stream, and I got a quick photo.
We were with retired forester Nick Ledgard, who spent much of his career working here. He had seen native galaxid fish in the stream before and thought it was trout free, since trout would have difficulty getting up past the cave system that Cave Stream is known for.
Looking at my photo later, I unfortunately confirmed that it was a brown trout.
NZers love trout and trout management is an important way to advocate for cleaner rivers. Still, it is also important for native fish conservation (especially non-migratory galaxid fish) that some stretches of our rivers remain trout free.