Exploring Periostracum as a Potential Environmental Proxy in Arctica islandica
Shells of the common marine bivalve, Arctica islandica, are being considered as a potential proxy for changes in food web and ecosystem dynamics in the Gulf of Maine, USA. A. islandica is considered a valuable proxy because of its extreme long life span (more than three centuries), and because it ha...
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Iowa State University Digital Repository
2015
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| Online Access: | https://lib.dr.iastate.edu/undergradresearch_symposium/2015/presentations/18 https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1106&context=undergradresearch_symposium |
| Summary: | Shells of the common marine bivalve, Arctica islandica, are being considered as a potential proxy for changes in food web and ecosystem dynamics in the Gulf of Maine, USA. A. islandica is considered a valuable proxy because of its extreme long life span (more than three centuries), and because it has prominent annual banding in the shell material. To explore this further we are exploring the stable isotopic values of carbon and nitrogen from shell periostracum along the axis of maximum growth and along the isochron (perpendicular to the maximum growth axis). The long term goal is to establish isotopic time series with dead-collected shells that have been radiocarbon dated and live-collected shells. Three hypotheses will be tested to examine the potential of A. islandica periostracum material to serve as an environmental proxy. (1) The periostracum will reflect the ambient conditions during the lifetime of A. islandica shells. (2) Because each isochron represents an identical time in the shell’s life, the values along the isochron should be similar. (3) A. islandica shells can be used to infer food web and ecosystem dynamics. |
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