NOAA's Ocean Acidification Program supports research that focuses on economically and ecologically important marine species. Research of survival, growth, and physiology of marine organisms can be used to explore how aquaculture, wild fisheries, and food webs may change as ocean chemistry changes.
A number of NOAA National Marine Fisheries Service Science Centers have state-of-the-art experimental facilities to study the response of marine organisms to the chemistry conditions expected with ocean acidification.
The Northeast Fisheries Science Center has facilities at its Sandy Hook, NJ and Milford, CT laboratories; the Alaska Fisheries Science Centers at its Newport, OR and Kodiak, AK laboratories; and the Northwest Fisheries Science Center at its Mukilteo and Manchester, WA laboratories. All facilities can tightly control carbon dioxide and temperature. The Northwest Fisheries Science Center can also control oxygen, and can create variable treatment conditions for carbon dioxide, temperature, and oxygen. These facilities include equipment for seawater carbon chemistry analysis, and all use standard operating procedures for analyzing carbonate chemistry to identify the treatment conditions used in experiments.
Both deep sea and shallow reef-building corals have calcium carbonate skeletons. As our oceans become more acidic, carbonate ions, which are an important part of calcium carbonate structures, such as these coral skeletons, become relatively less abundant. Decreases in seawater carbonate ion concentration can make building and maintaining calcium carbonate structures difficult for calcifying marine organisms such as coral.
Increased levels of carbon dioxide in our ocean can have a wide variety of impacts on fish, including altering behavior, otolith (a fish's ear bone) formation, and young fish's growth. Find out more about what scientists are learning about ocean acidification impacts on fish like rockfish, scup, summer flounder, and walleye pollock.
Shellfish, such as oyster, clams, crabs and scallop, provide food for marine life and for people, too. Shellfish make their shells or carapaces from calcium carbonate, which contains carbonate ion as a building block. The decreases in seawater carbonate ion concentration expected with ocean acidification can make building and maintaining calcium carbonate structures difficult for calcifying marine organisms like shellfish. This may impact their survival, growth, and physiology, and, thus, the food webs and economies that depend on them.
Plankton are tiny plants and animals that many marine organisms, ranging from salmon to whales, rely on for nutrition. Some plankton have calcium carbonate structures, which are built from carbonate ions. Carbonate ions become relatively less abundant as the oceans become more acidic. Decreases in seawater carbonate ions can make building and maintaining shells and other calcium carbonate structures difficult for calcifying marine organisms such as plankton. Changes to the survival, growth, and physiology of plankton can have impacts throughout the food web.
In 2010 and 2011, Alaska Fisheries Science Center (AFSC) scientists at the Kodiak Laboratory in Alaska tested the effects of lower pH due to increased carbon dioxide (CO2) on the survival, condition, and growth of red king crab (Paralithodes camtschaticus). Commercially important shellfish are a priority for AFSC research related to ocean acidification because of their economic value and because calcifying species are likely to suffer direct effects due to increased acidity (and a decrease in calcium carbonate saturation state) of our oceans.
The multi-year project objectives are to test the effects of CO2 enrichment (which leads to decreasing pH and lower saturation state) across a range of commercially important crab species and life stages (embryo, larvae, juveniles, and adults). The response variables currently measured include mortality, condition, growth, and calcification of the shell.
We will examine the effects of OA conditions (elevated pCO2) on the adaptive response of a potentially vulnerable native marine mollusc species with ecological, economic and social importance in the Pacific Northwest: geoduck clams (Panopea generosa). Geoduck clam larvae will be exposed to normal and elevated pCO2 and surviving larvae will be assessed using genomic sequencing to determine changes in allele frequencies at single nucleotide polymorphisms throughout the genome, and changes in the frequency of methylation states (epialleles) throughout the epigenome. Existing ecosystem models of OA consider a species' response to increased pCO2 as a fixed attribute; however, interpretations of the effects of OA at the population level may shift substantially if species adapt to the new environment. Furthermore, we will gain a better understanding of how specific genetic and epigenetic variations influence phenotype and the ability of an organism to respond, giving us new insights into fundamental aspects of species adaptation to environmental change.
Assessing a species’ risk to ocean acidification (OA) will depend on their duration of exposure to low pH/low saturation state conditions and their sensitivity to low pH conditions. Lab species exposure experiments attempt to measure species sensitivity to low pH. This modeling project estimates species exposure. In FY13, we started using an existing circulation/water quality of model of the Salish Sea and Washington/B.C. Coasts developed by the Pacific Northwest National Laboratory to understand carbonate chemistry exposure of zooplankton species. We are using empirical relationships between carbonate chemistry, oxygen, temperature and salinity to add carbonate chemistry to the circulation model. We then use an individually-based model to simulate the movement of various zooplankton species in this environment. In FY15-FY17, we will continue development and publication of results from this model, including exploration of current and future CO2 scenarios. Results from the model will inform the Dungeness crab exposure experiments planned for FY16, as well as general zooplankton vulnerability to OA.
Ecosystem models are used to estimate the potential direct and indirect effects of ocean acidification (OA) on marine resources. The population abundance and distribution of species that are sensitive to seawater carbonate chemistry can experience the direct effects of OA. Even species not sensitive to carbonate chemistry can have indirectly changes in abundance and distribution as a result of changes in their prey, predators, competitors or critical habitat forming organisms that are sensitive. Ecosystem models use information on food webs and other relationships to estimate these ripple effects of OA on important ecosystem services like fisheries.
Species exposure experiments that measure the response of organisms reared in seawater with manipulated carbonate chemistry are an important way to learn about the potential effects of ocean acidification (OA). Experimental systems that closely mimic the natural environment (e.g. with multiple stressors) can lead to studies with greater ecological relevance. Using a combination of NWFSC and OAP funds, the NWFSC built a facility for conducting species exposure experiments at the Montlake Lab, and has started a new facility at the Mukilteo Field station. The facilities include both rearing aquaria and a lab for carbon chemistry analysis (DIC, alkalinity, spectrophotometric pH). The NWFSC experimental systems are considered “shared-use” facilities, in that the systems are available for NWFSC research teams and outside collaborators as capacity allows. In the past, we have worked on collaborative projects with PMEL, University of Washington, Oregon State University, Suquamish Tribe, Evergreen State University, Cal Poly and Western Washington University. These collaborators often provide external funding for experiments, greatly increasing the research that can be conducted.