Farmed fish doing alright at CO2 levels twenty, fifty, seventy times higher than today
The World Wildlife Fund tells us that global CO2 is bad for global fish stocks, but ponder that professional fish farms can reach levels of CO2 twenty or even seventy five times higher, and the fish appear to be doing OK. Current guidelines for fish farms even suggest that “safe limits of CO2 range from >5000 to >30 000 µatm*” which are “12.5 to 75 times higher than current atmospheric levels”.
So in another few thousand years we might really get into trouble with fish farms and climate change then? (Or maybe we won’t. James Hansen estimates if we burn every last barrel of fossil fuel on Earth we’ll get to 1,400ppm. The experience of fish farms all over the world is that fish can apparently adapt to levels ten times higher even than this worst case scenario.)
We have a situation where there are scores of reports fish suffering from ocean acidification and high CO2 levels, but they don’t mesh with the reality that fish farms have been dealing with for decades. A new paper tries to figure out why this is so.