Ocean Acidification

Ocean Acidification and Hypoxia

Global carbon emissions are driving changes not only to the Earth’s climate, but also to the chemistry of the world’s oceans. The oceans are acidifying as they absorb a significant share of the carbon dioxide released by the burning of fossil fuels and changing land uses. This phenomenon, known as ocean acidification, often co-occurs with hypoxia (low dissolved oxygen) due to warmer water temperatures and accelerated nutrient delivery from land.

Changes in ocean chemistry have enormous implications for the health and productivity of California’s coastal and ocean ecosystems and the communities and industries that depend on them. From corroding shells and skeletons of marine organisms to disrupting normal fish behaviors, ocean acidification has the potential to alter marine food webs and ecosystems and the benefits they deliver to society, including California’s $45 billion ocean-based economy.

The U.S. West Coast is exposed to some of the lowest and most variable pH waters, and it is likely to be among the first places to experience the biological and economic effects of ocean acidification. In California, several top coastal fishery resources and the industries they support are at risk, including West Coast Dungeness crab, market squid, and shellfish aquaculture species (e.g., oysters, mussels). Addressing this threat requires a sustained, multipronged approach to both mitigate acidification at a local and statewide scale and manage the resulting disruptions.

Taking Action

California is a leader in climate and ocean science. We have studied the threat that acidification poses to our coastal communities and environment – but now it’s time to act. California Coastkeeper Alliance is working to guarantee that California takes no-regret actions to prevent local ocean acidification and hypoxia hot spots through policies and regulations that control nutrient pollution from sources like wastewater treatment facilities, stormwater runoff from urban areas, and agriculture runoff from rural areas, which feed algae and bacteria that exacerbate acidic and hypoxic conditions in coastal waters. To download CCKA’s Ocean Climate Resiliency Action Plan, click here.

CCKA has long advocated that the State Water Board apply Clean Water Act protections to address ocean acidification. In 2010, CCKA advocated that the Water Board list coastal waters impacted by hypoxia and ocean acidification as impaired pursuant to Section 303(d) of the Clean Water Act. The West Coast Ocean Acidification and Hypoxia Panel’s 2016 Report recommends that the State Water Board take the first step to do so by developing water quality standards to address ocean acidification. CCKA is working with the State Water Board to identify parameters that can serve as a basis to update the California Ocean Plan with revised water quality standards that will prevent ocean acidification and hypoxia hot spots. CCKA is also working with the State Water Board and Ocean Protection Council to improve water quality for Marine Protected Areas and Areas of Special Biological Significance to act as a network of ‘hope spots’ in the face of climate change threats.

California Waterkeepers and Blue Business Council Members are helping to collect science about how ocean acidification is affecting coastal areas and estuaries. Orange County Coastkeeper is partnering with scientists to assess the potential benefits of their eelgrass restoration in Newport Bay to help mitigate acidic conditions. Blue Business Council Member Hog Island Oyster Company is partnering with UC Davis Bodega Marine Lab and the California Current Acidification Network (C-CAN) to provide data that is used to inform decisions on Coastal policy at the state level through the California Ocean Protection Council.

CCKA is an affiliate member of the International Alliance to Combat Ocean Acidification.

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