Temporal trends in the Holocene: exploring implications for conservation paleobiology through quantitative assessment of marine mollusks
Conservation paleobiology is a relatively new field which applies the theories and analytical tools of paleontology to problems concerning the conservation of biodiversity. The use of data from stratigraphy, sediment or ice cores, fossil collections, and/or other specimens that provide temporal, ecological, or environmental information from both the recent Holocene and deep-time fossil records can be used to understand the ecological and evolutionary responses of species to changes in their environment. In one study, we analyzed changes in shell morphology from Pre-Columbus through present time for a heavily exploited, large marine gastropod, Strombus gigas (the queen conch), on San Salvador Island, the Bahamas. Overall, we observed an increase in harvested juveniles and an initial increase in shell size with a decrease in more recent time. Increased proportions of harvested juveniles and increasing size followed by a decrease in size in more recent time is consistent with increased stress on fisheries due to overfishing in the late 20th century. In a second study, we examined trace element concentrations preserved in the shells of two Holocene marine bivalve taxa, Potamocorbula amurensis and Cyrenodonax formosana from the Pearl River delta, China. We explored the use of trace elements as potential proxies for environmental change within the context of the sedimentological and faunal history of a previously described drill core from the Pearl River delta, China. Although the observed trace element signals are variable across bivalve species, they can be a useful tool in paleoenvironmental reconstructions.