Definitely a coarse fish fan (suckers as gamefish anyone?), and am presently smoking a batch of trout and white suckers. In the interests of a little research, found this link:
http://www.nrcresearchpress.com/doi/pdf/10.1139/f91-102
Which basically states that the presence of suckers can destroy or seriously alter the ability of waters to hold trout. So that argument appears settled on at least one front: suckers can destroy
trout water.
However, the reason may be surprising, because it's not through eating trout eggs.
It's because trout are almost primarily bottom feeders unless suckers are present -- suckers, having better-shaped mouths, force the trout to feed mid-water, which is an inferior source of energy (faster and less plentiful prey).
So essentially, trout are bottom feeders that get fat off of benthic organisms, unless suckers beat them to it and eat the trout out of house and home.
The main thing I thought remarkable was the proven reality that trout are equally bottom feeders alongside suckers. This shouldn't come as a surprise, given the rank taste they carry from ponds and lakes when high sun causes organic decomposition throughout the water column. You can taste the bottom in them, then.
The question then rises: is it biologically responsible to alter fish habitat away from suckers, who are naturally suited and naturally in most bodies of water in the province, and towards farmed trout, which aren't?