Marine creatures dissolving in acidic ocean waters: study

TORONTO – Corrosive ocean waters are causing the shells of some marine creatures to dissolve, says a new study.

Researchers studied a population of marine snails known as pteropods in the Southern Ocean whose shells are dissolving due to ocean acidification, a result of burning fossil fuels.

Scientists from British Antarctic Survey (BAS), the University of East Anglia, the US Woods Hole Oceanographic Institution and the National Oceanic and Atmospheric Administration (NOAA) studied the marine snails in 2008, and published the results this week in the journal Nature Geoscience.

They found that the shells of these creatures were “severely dissolved.”

The researchers said pteropods are a valuable food source and a “good indicator of ecosystem health.”

Up until this point, there had been research conducted into the effect corrosive waters could have on marine creatures, however there had been little evidence this was occurring in a natural environment.

The study supports predictions that ocean acidification is having a significant impact on marine life.

Ocean acidification is caused from an increase of carbon dioxide in the atmosphere. As more CO₂ is pumped into the air, more is absorbed into the world’s oceans, decreasing ocean pH and lowering carbonate ion concentrations.

Ocean acidification is widely regarded to be a serious threat to marine ecosystems. Many species of ocean creatures require certain levels of carbonate ion concentration in order to form hard shells and skeletons.

Lead author Dr Nina Bednaršek from the NOAA explained, “The corrosive properties of the water caused shells of live animals to be severely dissolved and this demonstrates how vulnerable pteropods are. Ocean acidification, resulting from the addition of human-induced carbon dioxide, contributed to this dissolution. ”

While the snails won’t necessarily die due to their shells dissolving, it will make them more vulnerable to predators and infection, said study co-author Dr. Geraint Tarling from BAS.

Pteropods are a source of food for birds and fish in the area, meaning changes to their population could also impact other parts of the food web, Tarling said.

In 2008, U.S. scientist Gretchen Hofmann called pteropods “one of our lead organisms for understanding and predicting the effects of climate change.”