Tjoepstil, there is absolutely nothing that is "virtue signalling" about discussing cause and effect. It doesn't require sophisticated understanding to appreciate the principle that humans and our food sources have evolved to exist within a specific spectrum of climatic conditions and that accumulations of industrial output that add new chemicals into these systems make these systems different from what we have evolved to need. Is it virtue signalling to say that it's good for humans to spend some time in the sun, to breathe oxygen, or to not eat plastic that is contained in current fish populations?