Small Australian sharks have been exposed as bigger homebodies than previously thought, in a study that took an existing chemical tracking technique and made it work for Great Barrier Reef sharks.
“Small-bodied sharks that are both predator and prey, such as the Australian sharpnose, may be particularly important links between food webs,” says lead researcher Dr Sam Munroe, who studied the sharks while at James Cook University in Townsville.
“Information on their movements can improve our understanding of how the ecosystems function, while also helping us predict species most at risk from the impacts of a changing environment.”
It was the first time the chemical tracking technique—known as stable isotope analysis—had been used to estimate shark movement over regional, coastal scales, and the results showed that they remained within the same 100km area for up to one year. The technique is often used to track land mammals, birds, and insects, and in marine animals (including sharks) over very large (e.g. whole oceans) or very small scales.
Different levels of elements such as carbon and nitrogen are naturally...
