Ba/Ca in cockle shells can be used as a salinity proxy

Our research focused on whether trace elements in Goolwa cockle shells (Donax deltoides) could be used as an environmental proxy. If so, this would provide a potential tool with which to trace past environmental histories for a region lacking high resolution environmental records. We collected cockles and water samples along an environmental gradient near the Murray Mouth and analysed both for a range of trace elements. Ba/Ca provided the best environmental indicator showing a negative relation between shell chemistry and recorded salinity. Ba/Ca in shells appears to be a suitable salinity tool and has the potential to provide an easily accessible and valuable proxy to gain insights into past environmental conditions that extend to before instrumental records existed.

The image to the right shows Danielle doing the cockle dance ably guided by a commercial fisher (Image: Chris Izzo)!

The following is a 3 min video on this research made possible using Elsevier’s audioslides.

For more information see our paper:

Izzo C, D Manetti, ZA Doubleday, BM Gillanders 2016. Calibrating the element composition of Donax deltoides shells as a palaeo-salinity proxy. Palaeogeography, Palaeoclimatology, Palaeoecology (publication date 24 Nov 2016).