Apparently that’s a thing. And, like ocean acidification, it’s not a good thing, at least for salmon:
After obtaining salmon embryos from a hatchery, the researchers transferred them into freshwater flow-through tanks with either ambient, high or variable concentrations of CO2. After 10 weeks, they tested the baby fish to see whether or not their development had been affected by the different conditions.
They found that not only were they smaller and lighter, but the fish’s senses were also impaired. The pink salmon larvae were more bold around new objects and did not seem to be afraid of alarm cues in the water that would normally prompt fish to flee.
Weight loss and impaired navigation
The fish also had an impaired sense of smell that prevented them from recognizing specific amino acids associated with the streams where they were born. This was significant because recognition of those amino acids is believed to play an important role in the fish’s navigational ability, said Ou.
There hasn’t been a lot o research into the effects of acidification on fish or other aquatic lifeforms, or belief that it would be much of a problem, in part because people believed the ocean would be well-enough buffered and in part because previous studies were on adult fish, who aren’t heavily affected by higher acidity in the water. Further, there have been few studies on freshwater species and systems – which are naturally more variable than the ocean – even though 40% of fish species are freshwater.