Species that are listed as threatened, and migratory species listed under international agreements are protected as matter of national environmental significance under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).
The Australian Government seeks to develop targeted collaborative programs to coordinate species recovery and environmental protection efforts across Commonwealth, State and Territory agencies with responsibilities for the marine environment. It also seeks relevant, accessible and evidence-based information to support decision-making associated with development proposals. The task of protecting listed species, however, is challenged by the number of species involved, and the number for which insufficient data are available to develop or measure progress against species recovery plans.
Marine species are listed under the EPBC Act in all categories from critically endangered to conservation dependent, and across most taxa including bony fish, cartilaginous fish, seasnakes, turtles, mammals, birds, and invertebrates. It is difficult to estimate the abundance of most of these species because they are typically both rare and widely distributed; for some species, such as the Largetooth Sawfish or Speartooth Shark, adults are rarely or never observed.
New methods are needed to assist with species recovery plans, to support managers in decisions relating to new development and non-detriment findings for the export of CITES-listed species, and to support international obligations. Marine Biodiversity Hub scientists, building on recent developments to estimate the abundance of over-exploited commercial fish populations, developed new genetic approaches combined with acoustic telemetry to estimate abundance and determine movement patterns and habitat use. These were applied to threatened river sharks in the Northern Territory, even when no adults could be directly sampled. The goal was to develop an effective and affordable technique that could be used for other rare and threatened mobile species.
Following the recent shark attacks in Western Australia attributed to White Sharks, the Australian Government requested Hub scientists to apply these new methods to estimating the abundance of the White Shark (eastern and western populations) as well as the Grey Nurse Shark (eastern population).