Big fish are found deep not because of age, climate, or prey, but because of us
I read a story once where ongoing changes in the timing of salmon runs were (of course) being blamed on climate change by scientists. But then someone who is actually in the fishing industry pointed out that for ages now we've been artificially selecting out those salmon which run during the "standard window", leaving in their wake mostly survivors who show up a little bit sooner or a little bit later, outside of that window. This person was of course then treated with absolute disdain by the online community which was discussing the issue; he might have even been banned outright for saying that.