Dungeness crab, Cancer magister, is a crustacean with great economic and ecological importance within the California Current System (CCS). The Dungeness crab fishery is one of the most economically important fisheries on the US West Coast, totaling over $200M in 2017 (Pacific States Marine Fisheries Commission, 2019).
Dungeness crab is also an excellent indicator of environmental change in oceans affected by climate change. Dungeness crabs are marine calcifying organisms, that is their shell consists of calcium carbonate which is obtained from ocean water. Ocean acidification makes obtaining carbonate ions difficult, therefore making building and maintaining calcium carbonate shells more difficult. It is for this reason that the Dungeness crab is an important indicator of changing environmental factors in the oceans.
Dungeness crabs have a life cycle that consists of five stages: egg, zoea larvae, megalopae larvae, juvenile, and adult. The Dungeness crab life cycle begins when female crabs release fertilized eggs into the water. After hatching, Dungeness crab enter the zoea larvae stage where the microscopic larvae live suspended in the ocean currents. The next stage is megalopae larvae, where the planktonic larval crabs begin to resemble adult crabs more and increase in size. Ocean currents carry megalopae larvae towards shore, where they begin their next life stage as juveniles. The juvenile stage lasts two years and can be found in shallow estuarine areas. The adult stage is harvested four years after hatching and can be found throughout the sandy and muddy areas in the shallowest parts of lower estuaries to depths of 2,000 feet.
Our project will focus on the larval stages of Dungeness crab as they can be used to study the effects of changing ocean conditions on planktonic organisms. Dungeness crab larvae are most abundant in the plankton of the California Current System during winter and spring. The larvae vertically migrate through the water column and occupy the surface layer during the night and early morning. They return to deeper waters during the day to avoid predation. Dungeness crab larvae are an interesting subject to study and hopefully will provide some understanding about how ocean conditions affect planktonic organisms in the California Current System.
Sources
Pacific States Marine Fisheries Commission. (2019). Species Report: Commercial Land Catch: Metric-Tons (mt), Revenue, and Price-per-pound (Price/Lbs). Portland, OR: Pacific States Marine Fisheries Commission.
Hobbs, R. C., & Botsford, L. W. (1992). Diel vertical migration and timing of metamorphosis of larvae of the Dungeness crab Cancer magister. Marine Biology, 112(3), 417–428. https://doi.org/10.1007/BF00356287
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