Australian blacktip shark

] . The flesh has a relatively high mercury concentration

Threats

Of the 1025 chondrichthyan species found worldwide, approximately 300 are found in Australia and over 50% of these Australian species are endemic. Commercial, indigenous, recreational and game fishers target them, and sharks are a by-catch or by-product in at least 70 types of commercial fishing operations.cite journal |author=Ovenden J. R.; Street R.; Broderick D.|year=2006|title=New microsatellite loci for Carcharhinid sharks(Carcharhinus tilstoni and C. sorrah) and their cross-amplification in other shark species|journal=Molecular Ecology Notes |volume=6|issue=2|pages=415-418|] C. tilstoni is one of seven commercial species that make up this fishery. Stock assessment for the shark resources in Queensland has not been undertaken and the sustainability of the shark resource at the current harvest and effort levels both there and in the Northern Territory (which are the only areas where "C. tilstoni" is found) are yet unknown. Shark fisheries are particularly sensitive to overfishing. Slow growth rates, low rates of reproduction and a close relationship between stock size and recruitment in shark population typically contribute to a rapid decline in numbers soon after exploitation begins. For a fishery to be viable over the long term, it must be managed effectively , and therefore it is of crucial importance for further research to be conducted, so that stock assessment can be properly made.

References