By Alyssa Jarrett
City on a Hill Press Reporter
Global warming. Everyone has heard of it, most understand it, many fight against it, but few know about its microscopic effects on the ocean. The concern about climate change focuses mostly on visible threats, like glaciers melting, rivers drying, and natural disasters intensifying. But many scientists at UC Santa Cruz are beginning to research ocean acidification, the gradual decrease in the pH of Earth’s oceans.
When fossil fuels are burned, carbon dioxide (CO2) accumulates in the atmosphere. The oceans dissolve much of this CO2 and become more acidic, disrupting the fragile environment for every marine organism.
Donald Potts, a UCSC professor of ecology and evolutionary biology, explained, “The pH of the ocean is pretty constant, around 8.2, because it is buffered by bicarbonate. Most of the CO2 in the water gets turned into bicarbonate, but over the last 10 to 20 years, less is being converted and that buffering system is no longer at equilibrium.”
One of the primary focuses of ocean acidification is a process known as decalcification, which causes the calcium carbonate shells of many marine organisms to dissolve, exposing them to predators. Corals, especially, are extensively studied because decalcification bleaches them of their vibrant colors and does not allow them to rebuild and grow.
“People are concerned about coral reefs because of tourism and the fact that they’re high in biodiversity,” Potts said. “Coral reefs have become the symbols of ocean acidification, because most organisms that are affected by it people know nothing about.”
However, ocean acidification is not just about decalcification, because virtually every marine organism will be affected even if they don’t have calcareous shells. Chris Dudenhoeffer, a third-year marine biology major, said that the gravity of global warming is universal to all species.
“Many organisms such as plankton and algae are temperature-sensitive,” he said. “Minor increases in temperature will effectively collapse the ocean food chain from the bottom up.”
Working with Potts on this issue is Adina Paytan, a UCSC associate research scientist, geochemist and paleoceanographer. In a collaborative project with UC Davis and UC Berkeley, UCSC scientists like Paytan are conducting experiments using water with different levels of CO2.
“Most of the work that has been done is on open water with organisms like plankton and coral,” Paytan said. “We’re working with intertidal organisms that dominate the California coast.”
Potts and Paytan hypothesize that because Monterey Bay’s colder waters and upwelling already create a relatively low pH, these organisms may be able to adapt and survive in more acidic water. Ocean acidification can often be a pessimistic issue, but Paytan asserted, “The world is not going to collapse and disappear. It will not be a doomsday, but it will be a different world.”
As for solutions to ocean acidification, Potts believe that nothing can be done in the short term.
“It is not possible to return CO2 to pre-industrial levels,” he said. “All we can do is be more proactive and practice immense restraint.”
Potts said the real solution to climate change is to move away from carbon-based fuels.
Informing people about ocean acidification is a big part of an even bigger battle against global warming, and Potts and Paytan are more than willing to share their expertise on this complicated subject.
“Climate change is a very hot topic, and we’re going to learn a lot in the next few years,” Paytan said. “It’s exciting and fun, and I encourage anyone interested in science to get involved.”