Add Screwed-Up Fish Skeletons to the List of Possible Climate Change Horrors - Gizmodo
Gizmodo.com - Wed 9 Jan 21:13 GMT

Add Screwed-Up Fish Skeletons to the List of Possible Climate Change Horrors - Gizmodo

Thanks to carbon dioxide emissions, Earth’s seas are getting both warmer and more acidic. Until now, the consequences of ocean acidification were thought to be mostly limited to marine animals that make hard, calcium carbonate shells, but new research suggest…

  A swimming little skate.Photo: Valentina Di Santo Di Santo took newly-laid skate egg cases and placed them in a tank setup under one of four different treatments that either had a modern or hotter, “future” temperature (as forecast for the year 2100) as well as a current or more acidic pH. She let the embryos develop over the next several months, and as soon as the baby skates hatched, Di Santo scanned their skeletons using a special x-ray technique.

  Di Santo speculated the fish may be beefing up their skeletons as a consequence of other physiological processes related to dealing with the acidic conditions.

  Di Santo thinks this may be because baby skates grow faster width-wise in warmer water, and the mineralization process might not be able to keep up with skeleton growth.

  Underside of a little skatePhoto: Valentina Di Santo A skeleton that’s denser in some places and less dense in others will likely have profound impacts on how affected fish can get around.

  All of this is compounded by the expectation that bottom-dwelling fish like skates will seek cooler, deeper waters as oceans heat up, pushing them right into depths that generally have higher carbon dioxide concentrations, and thus lower pH. Di Santo said a key next step will be quantifying just how much more difficult swimming is for fish when faced with warming and acidification.