"Ocean Acidification"

This project aims to understand how surfclams are affected by the changing chemistry of their habitat.

Molly Roberts takes us behind the scenes of research on carbonate chemistry effects on the growth of this iconic species off Cape Cod.

Science to understand how ocean acidification affects West Coast marine ecosystems.

Oceanic measurements collected during a scientific cruise on NOAA ship Ronald H. Brown last week confirmed that a large area of poorly oxygenated water (known as hypoxia) is growing off the coast of Washington and Oregon. 

How will sea scallops and the fishing communities that rely on them fare as the ocean changes?

NOAA Fisheries' lab in Milford CT is known for its long-standing international research relationships, and is currently hosting post-doctoral researchers from Brazil to China, not to mention France, which is where Emilien Pousse hails from.

Scientists at the NOAA Fisheries Milford Lab are shining some light on ocean acidification by examining how a more acidic ocean affects something we care about: the oysters, surfclams, and scallops that we eat.

Approximately 30-50% of global anthropogenic CO2 emissions are absorbed by the world’s oceans (Feely et al. 2004, Sabine et al. 2004). Increased CO2 uptake by the oceans is expected to reduce surface ocean pH by 0.3 – 0.5 units over the next century, which would be the largest change in pH to occur in the last 20-200 million years (Feely et al. 2004). Ocean acidification reduces the calcium carbonate (CaCO3) saturation point. Dramatic reductions in calcium carbonate saturation have been observed in the North Pacific since the industrial revolution (Feely et al. 2004).

The North Pacific Ocean is a sentinel region for signs of ocean acidification. Approximately 30-50% of global anthropogenic carbon dioxide (CO2) emissions are absorbed by the world’s oceans. Dissolving CO2 increases the hydrogen ion (H+) concentration in the ocean, and thus reduces ocean pH. Corrosive waters reach shallower depths more so there than in other ocean basins, especially in Alaska, and so biological impacts will likely occur earlier than in many other places. Ocean acidification reduces the calcium carbonate (CaCO3) saturation point, which stresses calcifying organisms by making calcification more difficult. The Alaska Fisheries Science Center research plan will focus on commercially important fish and shellfish species, their prey (calcareous plankton) and shelter (corals). Ocean acidification will likely impact the ability of marine calcifiers, such as corals and shellfish, to make shells and skeletons from CaCO3. Ocean acidification may also affect fish, marine mammal and seabird species through reduced abundance of calcareous plankton at the base of the food web. Species-specific studies of shellfish, calcareous plankton, corals and fish will be conducted to understand physiological effects (growth and survival). The CaCO3 content of calcareous organisms is not well known and a survey of shellfish, calcareous plankton and corals will be conducted to assess species vulnerabilities to ocean acidification. The results of the species-specific studies will be incorporated into population and ecosystem models to forecast population and ecosystem impacts. Bioeconomic models of Alaskan crab fisheries will be used to forecast fishery performance for a range of climate and ocean acidification scenarios.

Coastal regions around Alaska are experiencing the most rapid and extensive onset of ocean acidification (OA) compared to anywhere else in the United States. By integrating observational data with species response studies, OA forecast models, and human impact assessments, it has been determined that Alaskan coastal communities and the vast fisheries that support them, have varying degrees of vulnerability to OA, ranging from moderate to severe. Areas that are most vulnerable are located in regions where fisheries are vital for the state and national economy, providing over $3 billion annually to the U.S. gross domestic product (GDP). Even a relatively small decline in one or more of the fisheries in the Gulf of Alaska or Bering Sea could have cascading economic impacts that could dwarf the combined impacts of other regions around the Nation.