How Fossil Fuels Can Kill Nemo

Orange Clownfish

If global warming has taught us anything, it’s that our actions however small can have a huge, unexpected impact, locally and globally. The fossil fuels we burn, the energy we waste can set off a chain of destructive reactions that affect even the smallest creatures in a dramatic way. Orange Clownfish, made popular by the Disney movie ‘Finding Nemo’, are coral reef fish that live among anemones with whom they have a symbiotic relationship. These fish live in relatively warm waters and like a lot of other marine species, are severely affected by ocean acidification. The ocean acts like a sink for carbon dioxide as it absorbs a large percentage of it from the atmosphere. A significant increase in the amount of this gas in the atmosphere leads to a corresponding increase in the amount absorbed by the ocean. This in turn is responsible for lowering the pH of water. This acidification is dangerous to clownfish and several other marine species as it alters their ability to perceive sound and smell.  This degrading effect on their auditory and olfactory senses implies that their attempts to respond to and evade predators would be unsuccessful. These fish lose their ability to identify kin and predators by way of smell. Hearing is also important in escaping predators, especially for juvenile clownfish. In an experiment conducted by Dr.Steve Simpson at the University of Bristol, Clownfish were placed in water which contained enough carbon dioxide to mimic today’s conditions. These fish were able to respond to predators successfully. But when placed in water containing carbon dioxide corresponding to the amount expected in 2050, the fish did not respond to the predators and could not evade them. So an increase in this greenhouse gas in the atmosphere comes with a decline in the number of clownfish. Although this species is not listed as threatened due to the large number of eggs they lay, finding Nemo may become much more difficult in the future.