By Jennifer Langston, November 2011 — posted on Sightline
Sue Cudd couldn’t keep a baby oyster alive.
Four summers ago, she’d start with hundreds of millions of oyster larvae at the Whiskey Creek Shellfish Hatchery on Oregon’s Netarts Bay. Sometimes, they’d swim for a couple of weeks. Then they’d stop growing before a crucial shell structure developed, or maybe the foot or eyespot. They’d feed poorly. Eventually the larvae would all die.
“They just sort of fade away,” said Cudd, who owns the hatchery with her husband. “In all the years I’ve been here, I’ve never seen this kind of consistent problem.” 
For months, the hatchery produced virtually no oysters. Because the commercially popular Pacific oyster spawns unreliably in Northwest waters, hatcheries grow larvae for everyone from multi-million-dollar seafood producers to beachfront shellfish gardeners. When those hatchery incubators have problems, the effects ripple across the $73 million West Coast oyster industry, which pumps more money into the regional economy than farmed clams, mussels, geoduck, and other forms of shellfish combined.  It would be like every tomato farmer in the state plowing the ground in spring and getting ready to plant, only to find they can’t get their hands on any tomato seeds.
It’s also a preview of what may be in store for the Northwest as fossil fuel pollution from cars, power plants, and other human sources changes the chemistry of our marine waters, making them more acidic and inhospitable to sea life. A mix of currents and chemistry has put the region’s waters on the leading edge of what scientists call “ocean acidification,”  a phenomenon that could introduce profound changes to the marine food web  and the industries and economies built upon it.
To change a trajectory that could disrupt essential ocean ecosystems, we must act quickly and decisively. Proven policy solutions can reduce carbon dioxide emissions and other drivers of ocean acidification, but political will is needed. Responsible stewardship of our oceans—which provide us with far more than just food or income—depends upon it.
Every day, the oceans do us a huge favor. Across the planet, they absorb nearly one million metric tons of carbon dioxide each hour,  removing about a third of the carbon dioxide  released into the atmosphere by human activities such as burning fossil fuels— coal, oil, and natural gas—and clearing forests that would otherwise speed up global warming. This seems, at first, to be a massively beneficial service.
But as oceans absorb carbon dioxide, they also become more acidic.  And they become potentially lethal to a wide swath of sea creatures, from clams to corals to plankton that play a role in the diets of many things you might see at a local aquarium.  Many of those species wind up on fishing boats and then dinner plates around the world.
The animals that struggle or dissolve in more corrosive seawater range from oysters,  a bedrock species in the Northwest’s lucrative commercial shellfish industry, to British Columbia’s endangered northern abalone,  to the tiny cornerstones in the marine food chain like krill and pteropods,  sea snails propelled by wing-like feet that make up more than half of the diet of some young Alaska pink salmon. So what might increasingly acidic oceans look like?
“We won’t see a total collapse of food chains, but we will see substitutions,” said University of Washington associate professor Terrie Klinger during a Congressional hearing on the possible effects of ocean acidification. “We may end up with food chains or food webs that are highly undesirable and not productive for the means we use them today.” 
Those predictions rattle Charissa Sigo, 18, who comes from a long line of fishermen and women in the Suquamish Tribe. Last year, the Washington tribe commercially harvested more than 415,000 pounds of geoduck clams, using those profits to fund social service programs and disbursements to elders. Individuals caught more than 750,000 pounds of crab, clams, shrimp, and salmon.  It fed their families, bought new appliances, sent kids to college, and upheld their traditions.
“My people come from water so we basically live off the water. We go canoeing and a lot of our food comes from the water, the salmon and the crab and the shellfish. If sea life is suffering, our people are too, or will be,” said Sigo. “My fear is that…our culture will die off, and we’re going to have to adapt and change to something else.”
There is still much we don’t know about how changes from ocean acidification will ripple through local waters and the region’s economy. We’re essentially conducting the world’s largest chemistry experiment, and results are just starting to come in. Yet we do know the basics, and they’re important for the Northwest:
* Surprisingly corrosive water  has already been found off our shores.
* Acidified water showed up decades before scientists expected  to see it.
* The best way to prevent more serious acidification is to reduce carbon dioxide emissions. 
What do we know about ocean acidification?
Read the rest of the story on Sightline Report • Ocean Acidification • November 2011