A panel of ocean scientists from Washington, Oregon and California said Monday that local action on the West Coast — one of the regions of the world hardest hit by ocean acidification — could soften the blow of this rapidly worsening global problem.
While acidification's main cause is carbon dioxide emitted globally, the West Coast Ocean Acidification and Hypoxia Science Panel said it's urgent to fight the phenomenon close to home as well as globally.
Changing ocean chemistry has already taken a toll on the Northwest shellfish industry. As oceans absorb more of the carbon dioxide that humans keep adding to the atmosphere, it will only get harder for shellfish and plankton to grow shells as seawater turns more acidic.
Ocean acidification and the related problem of hypoxia, or low oxygen levels under water, "will have severe environmental, ecological and economic consequences for the West Coast," the panel's report states.
Especially in semi-enclosed seas like Puget Sound, local processes as well as global atmospheric pollution shape ocean chemistry.
The panel, made up of 20 ocean-science experts, called for reducing pollutants that drain into water bodies like Puget Sound from surrounding cities and farms.
Pollutants like the nitrogen and phosphorous in fertilizer runoff help turn the sound more acidic than it used to be. As algae blooms fueled by nutrient runoff die and decompose, they consume oxygen, generate carbon dioxide and contribute both to hypoxia (low oxygen levels) and increased acidity.
"Within Puget Sound, we have the opportunity to improve water quality, and that will help reduce some of the most negative impacts of ocean acidification," Terrie Klinger, report coauthor and University of Washington ecologist, said.
Reducing stormwater runoff is no easy feat: it often involves politically difficult moves like changing land-use patterns or regulating how shorelines are developed. Cities and counties throughout Washington are currently updating their shoreline regulations, a roughly once-a-decade process.
Klinger, the director of UW's School of Marine and Environmental Affairs, could not say how much the panel's recommendations would cost.
"Some of them will cost more than others," she said. "But in the end, they're likely to be far less costly than ignoring the problem."
The scientists also recommended restoring underwater vegetation that removes carbon dioxide from seawater.
"Kelps because they grow very quickly and eelgrass because it has other great properties associated with it," Klinger said.
Eelgrass can absorb nutrients like nitrogen and phosphorous, help slow erosion and provide cover for small fish and shellfish. Eelgrass meadows cover about 60,000 acres in Puget Sound, a slight increase from previous years, according to the Washington Department of Natural Resources.
The panel said reducing the world's carbon dioxide emissions is still the most important step to take to protect the chemistry and life of the oceans.
In response to the panel's report, Washington Gov. Jay Inslee issued a statement saying he's ready to take action with the other West Coast states to tackle ocean acidification.