Rising Carbon dioxide Levels Preventing Sea Snails from Jumping

Sea snails often jump to avoid predators. A latest study from Australia has found that rising levels of carbon dioxide in the oceans could disrupt snails' decision-making skills and in turn affect their jumping abilities.

The study was conducted by researchers at the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) and James Cook University. The team found that the conch snail either takes longer to jump or even stops jumping altogether, when exposed to higher levels of carbon dioxide.

Disrupted Messages

Ocean acidification is an unfortunate consequence of the industrial revolution. Excess burning of fossil fuels has resulted in the release of billions of tons of carbon dioxide in the environment. This has led to a drop in the sea-surface pH. The increase of carbonic acid in the oceans inhibits growth and development of marine life.

In the present study, researchers found that higher levels of acidity disrupted a key neurotransmitter receptor in the snails' nervous system, affecting their ability to make a quick decision. In the unforgiving depths of the ocean, a late decision means instant death.

Researchers found that the snails' failure to jump made them a 'quick meal' for the marbled cone shell. The cone shell is a slow-moving marine creature that captures its prey by shooting poisonous darts.

Changes in eating habits of marine organisms could affect the entire food web.

"Altered behaviors between predators and prey have the potential to disrupt ocean food webs," Sue-Ann Watson from the ARC Centre of Excellence for Coral Reef Studies, according to a press release.

And it is not just the snails that are being affected by the changes in the neurotransmitter receptor. Previous research has shown that several creatures including fish rely on this mechanism to escape.

"This neurotransmitter receptor is common in many animals and evolved quite early in the animal kingdom. So what this study suggests is that human carbon dioxide emissions directly alter the behavior of many marine animals, including much of the seafood that is part of the human diet," said Professor Göran Nilsson, from the University of Oslo, co-author of the study.

Related study had found that ocean acidification and climate change are ruining the digestion of marine organisms such as sea urchins.

Double whammy

A lot of research on oceanic acidification has mainly focused on calcification of shells in both snails and related organisms. The latest study shows that in the future snails will not only have to deal with weaker shells, but also impaired decision-making abilities.

The study is published in the journal Biological Sciences.