Following up on an earlier post about how hard body parts can be used to reconstruct environmental signatures, Dr Zoe Doubleday and her team have identified the relative contribution of water (that the fish are swimming in) and diet to otolith (fish ear bones) chemistry in freshwater fish. Now I know that this isn’t strictly a study about oceans, but the techniques and findings of this paper are extremely useful if you want to do this in the ocean as well! See her report below.
Otolith chemistry is used extensively around the world to address key questions relating to fish ecology and fisheries management, particularly in marine systems. Nevertheless, there is limited research on the relative contribution of water and food to elements within otoliths.
Using a controlled lab experiment, researchers at the University of Adelaide sought to address this gap by explicitly testing the relative contribution of water and food in three iconic Australian freshwater fish species — silver perch, golden perch and Murray cod. Water was found to be the key, but not sole, contributor to otolith chemistry in all fish species. This research will improve interpretation of otolith chemistry data in freshwater fish and will help to build a more accurate picture of their movements and the environments they inhabit.
Read journal article here: http://bit.ly/12pHsLr