Underneath the picturesque Salish Sea there are churning currents, with water swooshing in from the open ocean and surges of nutrient-rich fresh water from creeks and rivers that alter the sea’s chemistry — and can make life tough for species trying to survive in a rapidly changing environment.
And that’s why scientists are increasingly interested in the Salish Sea as they study ocean acidification — often called the evil twin of climate change.
The impacts of ocean acidification range from coral reef bleaching in the Caribbean and South Pacific to the hardships faced by oyster and mussel aquaculture businesses in the Salish Sea because shellfish are unable to form calcium carbonate shells.
The Salish Sea is a network of coastal waterways that includes the Strait of Georgia, the Strait of Juan de Fuca and Puget Sound. Researchers are interested in the differences between the semi-enclosed body of water near Vancouver and Seattle and the more exposed outer coast.
“We are a bit of a canary in a coal mine,” said Jay Manning, chair of the leadership council for the Puget Sound Partnership, a group charged with restoring the health of Puget Sound.
‘Stuck with acidic oceans for thousands of years’
The basic science of ocean acidification is simple — the ocean is absorbing carbon dioxide from the atmosphere, which reacts with sea water and creates a weak carbonic acid.
In the Pacific Ocean, deep acidic water circulates for years and then surfaces in upwellings along the West Coast.
It isn’t a problem that is going to correct itself, even if humanity swears off fossil fuels tomorrow and, as oceans cover 71 per cent of the world’s surface and house 80 per cent of our biodiversity, acidification could disrupt food supplies and destroy coastal communities.
More than 80 per cent of the heat generated by climate change and about 30 per cent of carbon dioxide released by human activities since the start of the Industrial Revolution has been absorbed by the ocean.
“We are going to be stuck with acidic oceans for thousands of years, if not for millenia,” Kim Juniper, a University of Victoria professor who holds the B.C. leadership chair in marine ecosystems and global change told DeSmog Canada.
An eight-year study by 250 scientists found that, even if global warming is held to no more than two degrees, there will be irreparable damage.
That means winners and losers, with shellfish and small creatures such as pteropods — a tiny sea snail that serves as food for salmon and other fish — on the losing end and jellyfish and sea grasses among organisms that could thrive.
“We are a bit of a canary in a coal mine.” https://t.co/BkDeudGP9W— DeSmog Canada (@DeSmogCanada) March 12, 2018
‘Is there time to adapt?’
On the West Coast, ocean acidification sprung to public consciousness more than a decade ago when exceptionally low pH levels — meaning the water was more more acidic than usual — killed 100 per cent of young oysters at two major hatcheries in Washington State.
“That got everyone’s attention on the West Coast. A lot of jobs were at stake and it went from being an interesting thing to talk about in the classroom to something we had to take action on,” Manning said.
Washington Governor Jay Inslee said categorically that “the ocean has had enough” as he announced a Blue Ribbon Panel to study ways to cope with the new reality. Meanwhile, scientists, politicians and non-governmental agencies from California, Oregon, Washington and B.C. started working together to look for information and solutions.
Fisheries and Oceans Canada research scientist Debby Ianson is one of the few researchers looking at ocean acidification in the Salish Sea and has found that areas such as the Strait of Georgia are naturally more acidic than the surrounding ocean and upwelling water from the outer coast increases pH levels in the Salish Sea, making the water less acidic.
“The question is whether the Salish Sea has always been this acidic and what makes it this acidic,” Ianson said.
And, as the water becomes more acidic, is there time for some of the organisms to be able to adapt to the increasingly corrosive water?
Researchers have already found that indigenous oysters do better in low pH waters than the larger Pacific oyster, which has been used by shellfish farmers for decades, said Susan Allen oceanographer and professor at the University of B.C. Department of Earth, Ocean and Atmospheric Science.
“Maybe we can develop strains that do better under these new conditions,” Allen said.
“By understanding the system and the impacts maybe we can mitigate and adapt,” she said.
Much of the research is in its infancy, and Ianson said that even the decline of pteropods in the Pacific Ocean may not be directly attributable to ocean acidification.
“They have been around for thousands or millions of years. They were around even when there was more CO2 in the atmosphere than now,” she said.
A study published last year in Nature found colonies of marine snails thriving in seawater that was 30 times more acidic than normal, a discovery that suggests some animals are able to adapt to ocean acidification.
Climate change raises ongoing questions
But, as the impacts of climate change increase, there is also the question of which creatures will be able to withstand the multiple stressors of increasing temperatures and decreasing oxygen, Ianson said.
One key to understanding what is happening in the water that surrounds us is to gather the essential baseline information. Sensors that measure pH levels are being installed at stations along the Ocean Networks Canada observatory system and on B.C. Ferries.
Jim Christian, research scientist with Fisheries and Oceans Canada and an adjunct faculty member at the University of Victoria, recently led an international workshop on gathering data to measure ocean acidification.
They are not easy measurements to make and autonomous sensors make more sense than having researchers take bottle samples, he said.
“These sensors are new and to some degree they are untested. There’s a lot of potential there… but it’s a long, slow process of getting the sensors in place and then we have to make sure the data are reliable,” he told DeSmog Canada.
The lack of historical data and the variability of acidity in the Salish Sea makes the task challenging, Christian said.
The Salish Sea saturation state in the surface water is low, meaning it is naturally acidic in the winter, with the summertime plankton bloom taking up carbon dioxide making it easier for shellfish to produce shells, Christian said.
“That may mean that the organisms that live there are well adapted to an environment that is naturally acidic or it may mean that it’s relatively close to a threshold that could be really bad for those organisms,” he said.
“What we do know is it’s a trend that is going on all over the world. In a place like this the natural variability is extremely large, but the long term trend goes in one direction,” Christian said.
The one certainty is that the only way to stabilize the oceans is a global effort to stop putting carbon dioxide into the atmosphere, which means a halt to burning fossil fuels, scientists agree.
But there are other actions that will help and work done in Washington State has confirmed that freshwater runoff and sewage are major contributors to acidification in Puget Sound.
“Get a good septic system if you care about the shells on your shore,” Ianson recommended.
On a small scale, experiments such as restoring eelgrass and kelp beds in the Hood Canal are also underway, Manning said.
“The idea is that, as plants grow in the water they absorb CO2 so they can buffer and raise the pH as the plant is actually growing. The question is what happens when the plant dies — does it re-release all that CO2 as it decomposes?” he said.
Image: In 2014 the U.S. National Oceanic and Atmospheric Association (NOAA) found evidence of pteropods, free-swimming snails found in oceans around the world, were unable to develop shells due to increased ocean acidity. Photo: NOAA