Conservation of elasmobranch species (sharks and rays) is an increasing priority globally, including for the Australian Government, as evidence of overexploitation of some species becomes increasingly apparent (e.g., Stevens et al. 2000, Graham et al. 2001, Clarke et al. 2006, Dulvy et al. 2008, Dulvy et al. 2014). Increased use of and reliance upon marine populations and products as a food source has seen elasmobranchs captured as target, byproduct and bycatch in fisheries around the globe (Dulvy et al. 2014). Based on scientific status assessments through the International Union for Conservation of Nature (IUCN) Red List process, current global estimates indicate one quarter of elasmobranch populations are threatened with extinction with five of the seven most threatened families comprising ray species (Dulvy et al. 2014). Recognition of the declining status of shark and ray populations is leading to increased protections for their populations in national and international waters. Australia has approximately 323 shark and rays species, with about half of these species being endemic. In Australia 13 elasmobranch species are currently listed in a threat category under the Environment Protection and Biodiversity Conservation (EPBC) Act (Table 1).
IUCN assessments are completed by scientists considered to be experts in the field and peer-reviewed for accuracy prior to acceptance on the Red List. These listings are a scientific assessment and as such do not have any regulative or statutory authority. They are, however, often used to guide management and conservation policy in many parts of the world and form a basis for international protections where required. Assessment of 175 Australasian species in 2003 revealed that 34 species were threatened (Critically Endangered, Endangered and Vulnerable), while 52 were Near Threatened, 71 of Least Concern and 59 species were considered Data Deficient (Cavanagh et al. 2003). In 2015 members of the IUCN Shark Specialist Group, Oceania Region convened a workshop to re-assess elasmobranch species within the region and include species not assessed previously. These assessments have been completed and reviewed for publication on the IUCN Red List in 2016. It is anticipated that the assessments conducted for Australian species will form the basis of ongoing and future consideration of increased national protection for species of concern.
Management and conservation of elasmobranch species is complicated by several factors. First, these species can be the target of directed fishing effort. Exploitation of these populations produces different levels of decline, some of which may be directed to reach maximum sustainable yield from fisheries. This situation differs dramatically from non-exploited and/or terrestrial species. Second, studying species in marine environments is complex due to the difficulty in locating and observing individuals. This often limits the amount of data available on which to make management and conservation decisions. Finally, many of these species undertake cross-jurisdictional movements and/or are considered migratory. This extended movement can lead to protection via international agreements such as the Convention on the Conservation of Migratory Species (CMS). Stronger international regulation can also be applied via the Convention on International Trade in Endangered Species (CITES). These international conventions have direct implications for management and policy within member states, including Australia.