A study of marine life in the temperate coastal waters of the northeast Pacific Ocean shows a reversal of competitive dominance among species of algae, suggesting that increased ocean acidification caused by global climate change is altering biodiversity.
The study, published online January 15, 2014, in the journal Ecology Letters, examined competitive dynamics among crustose coralline algae, a group of species living in the waters around Tatoosh Island, Washington. These species of algae grow skeletons made of calcium carbonate, much like other shelled organisms such as mussels and oysters.
As the ocean absorbs more carbon dioxide from the atmosphere, the water becomes more acidic. Crustose coralline algae and shellfish have difficulty producing their skeletons and shells in such an environment, and can provide an early indicator of how increasing ocean acidification affects marine life.
"Coralline algae is one of the poster organisms for studying ocean acidification," said lead study author Sophie McCoy, a PhD candidate in the Department of Ecology and Evolution at the University of Chicago. "On one hand, they can grow faster because of increased carbon dioxide in the water, but on the other hand, ocean acidification makes it harder for them to deposit the skeleton. It's an important tradeoff."
Scientists have been studying Tatoosh Island, located off the northwestern tip of Washington state, for decades, compiling a rich historical record of ecological data. In this study, McCoy and Cathy Pfister, professor of ecology and evolution at the University of Chicago, repeated experiments conducted in the 1980s by University of Washington biologist Robert Paine. McCoy transplanted four species of crustose coralline algae to test sites to study how today's ocean has changed how they compete with each other.
In the previous experiments, one species, Pseudolithophyllum muricatum, was clearly dominant, "winnin
|Contact: Matt Wood|
University of Chicago Medical Center