4 replies to this topic

[LepomisAuritus]

In the Atlantic slope drainages in the northeast, there are very few native large predatory fish (chain pickerel, redbreast sunfish, pumpkinseed, brook trout, and white/yellow perch) and all bass and most trout are introduced. Especially in rivers where I typically snorkel and fish, the sort of niche currently filled by smallmouth bass (introduced in the late 1800s) doesn't have a native equivalent. Is there any body of evidence on native fish (cyprinids, lepomids mainly) that dates back that early? I would think that species such as redbreast sunfish would not be able to fill the niche of piscivorous, fast water fish, so an increase in predation of native cyprinids in that habitat must have occurred. Are there any more modern examples (Midwest or west maybe?) of what sort of impact introduction of large predatory fish has? I know of introduced trout in New Zealand impacting native galaxias, but I'm not familiar with anything similar in North America. 

Edited by LepomisAuritus, 16 January 2019 - 08:51 PM.

[JasonL]

I think there were plenty of predatory species prior to bass and trout introductions, they were just different. Pickerel, larger Lepomis species, fallfish and creek chubs all helped fill the niche among others. Creek chubs and fallfish specifically can get fairly large and put a nice dent in various micro species populations. I'm sure there are others too I'm not thinking of right now.

[LepomisAuritus]

Forgot about fallfish. I occasionally catch huge ones, perhaps there were more specimens of this size pre-bass introduction. 

[olaf]

What about striped bass, Atlantic salmon, or American eels?

What was the natural range of burbot?

[LepomisAuritus]

A lot of the rivers would have american eel, and I assume the more coastal ones would have had salmon. Even then, studies show eels eat more insects than fish.  Maybe burbot in the north, but not as far south as the rivers I usually frequent. I saw Ben Cantrell had some fishing reports of native minnows in the West that co-exist with introduced bass, I wonder if he would know about the bass's impact out there.