Ocean Acidification

Ocean Acidification and Hypoxia

Climate change is changing the chemistry of the world’s oceans. The ocean is becoming more acidic, and hypoxic (meaning low oxygen) conditions are more frequent as the seas absorb carbon dioxide (CO2) and surface waters warm. Scientists have observed marine organisms that were having difficulty forming their shells due to ocean acidification impacts since at least 2004. More recent science indicates that growth, survival and behavioral effects linked to ocean acidification extend throughout food webs.

The West Coast of North America is facing some of the earliest, most severe changes in ocean carbon chemistry. Scientists have observed declines in the survival of shellfish larvae in hatcheries, and major hypoxia-induced crab mortality events. Warmer and acidifying waters threaten the health of California’s marine ecosystems, and the seafood industry and many other businesses and communities that depend on a healthy ocean. In 2015, an unprecedented toxic algal bloom off the West Coast hurt sea lions and produced the deadly neurotoxin domoic acid in crab and other sea life.

Taking Action

As we grapple with changes to our ocean of an unprecedented magnitude and scale, California Coastkeeper Alliance is urging action by communities and regulators to mitigate impacts and to make our marine ecosystems more resilient to change. CCKA is advocating for policies and regulations to reduce nutrient and organic matter pollution, which feed algae and bacteria that exacerbates acidic and hypoxic conditions in coastal waters. In particular, wastewater treatment plant upgrades and agricultural pollution source controls can mitigate local ocean acidification hot spots.

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 will work with the State Water Board to identify parameters that can serve as a basis to update the California Ocean Plan with revised water quality criteria. 

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 also working with the State Water Board and Ocean Protection Council to make the ocean more resilient to acidification and hypoxia through robust implementation and support for the network of Marine Protected Areas.

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

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