Global carbon dioxide emissions are causing massive changes to ocean chemistry along the U.S. West Coast, prompting scientists to call for rapid, decisive actions and coordinated efforts from the governments of Oregon, California, the state of Washington and British Columbia in Canada to mitigate the effects.

A 20-member panel of leading ocean scientists made this conclusion and presented their report on April 4, highlighting the troubling increase in ocean acidification and hypoxia, which is marked by extremely low levels of oxygen.

Oregon State University (OSU) marine ecologist Francis Chan, co-chair of the West Coast Ocean Acidification and Hypoxia Science Panel, believes that ocean acidification is an international problem that can be solved locally.

“There has been an attitude that there is not much we can do about this locally, but that just isn’t true. A lot of the solutions will come locally and through coordinated regional efforts,” he says.

The report identified global carbon emissions as the leading cause of ocean acidification, leading the panel to encourage West Coast leaders to develop a regional carbon management strategy to reduce the CO2 levels absorbed by the ocean.

But what is happening here exactly?

As humans pump more CO2 into the atmosphere, ocean waters absorb the gas, resulting in their acidification. Hypoxia, on the other hand, results from burning fossil fuels, along with agricultural runoff and waste water treatment effluent.

The West Coast is particularly vulnerable to rising seawater acidity levels because of the operation of ocean currents. Coastal upswelling brings nutrient-filled, low-oxygen, high-CO2 water from deep in the water column to the surface near coasts. The nutrients fortify the water column, triggering phytoplankton blooms that die and sink to the bottom to produce more CO2 and lower oxygen levels further.

Some of the initial impacts were already felt 15 years ago in Oregon when it experienced season hypoxia, leading to a number of marine animal die-offs. The oyster industry, too, was fraught by high death rates among juvenile oysters due to increasingly acidified water.

There is plenty at stake for these West Coast communities, where fisheries serve as primary economic drivers and quality of seafood is on the line. In Washington state, for instance, shelled organisms are already having a hard time forming their protective outer shells, with the local shellfish sector confronted with high mortality rates in the early-life stage of some shellfish species.

The report was commissioned by decision-makers from various states, who convened a panel of scientists and then created a report that warns and maps solutions at the same time.

Its recommendations include the development of new criteria for near-shore water quality, the improvement of CO2 removal methods by using kelp beds and other plants as well as adaptability enhancement through promoting marine reserves and other resource management methods.

Among the proposed solutions is putting up “listening posts” around the West Coast – such as the Whiskey Creek Shellfish Hatchery in Oregon that solved juvenile oyster die-offs – that demand a multi-stakeholder response.

“It is a unifying issue that will require participation from state and federal agencies, as well as universities, ports, local governments and NGOs,” says OSU professor and panel member Jack Barth.

With the acidity of West Coast waters expected to continue to accelerate with rising CO2 levels, scientists and state officials are leaving no stone unturned. Members of the Washington Marine Resources Advisory Council plan to approach the state legislature next year for increased research, monitoring and outreach funding.

The state’s ocean acidification center, too, has forged partnerships to conduct experimental studies on Dungeness crab, salmon and sablefish.

There is no one silver bullet for solving the problem, as different coastlines and habitats respond differently to treatments. Chan, though, remains highly optimistic, fueled by “the receptivity of the decision-makers at the state level.”

Photo: Oregon State University | Flickr

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