Throughout recent decades, the Suquamish Shellfish Program has contributed to research within Puget Sound, including Dungeness crab life stages and reproduction studies, Olympia oyster restoration efforts, and drogue tidal current studies. During recent years the threat of Ocean Acidification has become a major concern in the world’s oceans, and it is now the number one focus of research within the Suquamish Shellfish Program.
Ocean Acidification (OA) is defined as a rapid increase in seawater acidity (a drop in pH level) as a result of significant increases in carbon dioxide in the earth’s atmosphere, which is subsequently absorbed by the oceans. This increase in carbon dioxide has come as a result of burning fossil fuels like oil and gas for many decades, and this trend continues today. In fact, the acidity of saltwater is changing faster now than at any other time in the history of life on earth. Sixty-five million years ago when dinosaurs became extinct, there was a huge shift in ocean acidity, but the rate of change today is even higher.
What are the effects of OA on the marine ecosystem?
Water has to have the right chemistry to support life, including the right salinity, the right amount of dissolved oxygen, and the right pH (acidic/basic balance). Land animals maintain their water chemistry balance within their bodies, and they can regulate it by what they eat and drink. Fish and other aquatic organisms however, live surrounded by water, so they are very sensitive to changes in water chemistry. For example, OA may have significant effects on local Dungeness crab populations, clam and oyster populations, and zooplankton which are a critical foundation within the marine foodweb. One of the major concerns about OA is that it can cause the calcium shells and exoskeletons of shellfish to dissolve or inhibit shell formation, especially in juvenile shellfish. This dissolving of calcium shell has been seen in juvenile pacific oysters and has already greatly affected populations in certain regions within Washington. Overall, the known effects of OA are limited, and there is much to be learned in the coming years.
Addressing the OA Challenge
The Shellfish Program is approaching the OA challenge with a three part strategy: 1) Research to understand when and how particular species will be impacted; 2) Monitor to understand the extent of acidified waters and seasonal fluctuations; and 3) Outreach and Education to inform the community about what they can do to minimize OA impacts on aquatic species and themselves. To implement this strategy the Shellfish Program has acquired funding from US Fish and Wildlife Service, the Environmental Protection Agency (EPA), the Bureau of Indian Affairs (BIA), as well as assistance and collaboration from many other partners.