Estuary Stingray - Human Interactions

Human Interactions

Historical and anecdotal evidence strongly suggest that the once-abundant estuary stingray has declined substantially across its range. Although it is not commercially utilized, it faces a number of other threats. This species is captured incidentally by commercial bottom trawl and gillnet fisheries; bycatch mortality is exacerbated by the practice of "spiking", in which the ray's cranium is pierced with a metal bar or sharpened stick so as to move it. It is also readily caught, and often killed, by recreational anglers. Surveys in Moreton Bay have found fishing-related effects, such as embedded hooks and mutilated tails, in over 10% of the population. Habitat degradation is another major threat to the estuary stingray, especially given its habitat specificity. Its range encompasses some of the most urbanized areas in Australia, where there is extensive land reclamation, water pollution, and construction of flood mitigation barriers on rivers. Finally, this ray's reputation for damaging shellfish has led to persecution by commercial shellfish farmers.

The estuary stingray's diminished population and susceptibility to multiple threats have led the International Union for Conservation of Nature (IUCN) to assess it as Vulnerable. Demographic modelling has shown that it is likely to become Endangered without intervention. Several Marine Protected Areas (MPAs) are located within its range, but at present they lack adequate protection from fishing. As this ray remains locally abundant in Hervey Bay and parts of Moreton Bay, these areas may become important centers for preserving the species. The Queensland government has listed the estuary stingray on the Back on Track species prioritisation framework, to facilitate the development of conservation measures.