Hammerhead Sharks

Threatened Status:

  • Great Hammerhead Endangered (IUCN); not listed (EPBC Act 1999)
  • Scalloped Hammerhead – Endangered (IUCN); Conservation Dependent (EPBC Act 1999)
  • Smooth Hammerhead – Vulnerable (IUCN); not listed (EPBC Act 1999)

Location:

  • Great Hammerhead: NSW, QLD, NT, WA
  • Scalloped Hammerhead: NSW, QLD, NT, WA
  • Smooth Hammerhead: NSW, VIC, TAS, SA, WA

 

Hammerhead sharks are an iconic species inhabiting Australia’s waters. But they are under threat, and in some cases even endangered. To save our hammerheads, we must implement stronger levels of protection for them and reduce fishing pressure.

 

About Hammerhead Sharks

  • The unique ‘hammer’ shaped head helps the shark zone in on prey by detecting the direction of a scent, and enabling it to see prey both above and below at the same time.
  • Like humans, hammerhead sharks are long-lived, reach maturity after several years, and have few babies. These characteristics make them particularly vulnerable to overfishing.
  • Australian hammerhead shark populations are in decline. Scalloped hammerheads are estimated to have lost up to ~80% of their original population in QLD waters (2).
  • Hammerhead sharks are particularly vulnerable to being caught in gillnets (fishing nets) because of the unique shape of their head.

 

Are Hammerhead Sharks Endangered?

Scalloped hammerhead sharks are listed under the EPBC Act, the piece of Australian law that governs how we protect endangered wildlife from threats. Although their low numbers means they qualify for an ‘Endangered’ listing, they are listed under the ‘Conservation Dependent’ category, which means commercial fishing for this endangered species can continue.

‘Conservation Dependent’ is an odd category created specifically for fish. This seemingly protects the interests of commercial fishing at the expense of our environment and wildlife – by allowing continued fishing of threatened species if a plan to manage the capture of the species is in place. Under this category, 78 tonnes of hammerhead sharks can be caught in the Great Barrier Reef, the largest catch of the species anywhere around Australia.

Great and smooth hammerheads have no protection under the EPBC Act and are not listed to date.

By contrast, the IUCN, an international body that assesses the conservation status of wildlife, assessed great and scalloped hammerheads as endangered and smooth hammerheads as vulnerable (3, 4). Great and scalloped hammerheads are already listed as threatened species in NSW and it is illegal to fish for them in NSW state waters (5).

There is concern that the numbers of hammerhead sharks killed in fishing is under-reported in fishing records, so we do not know how severe the issue really is – it could be worse than we imagine. Many fishery reports have historically only reported the number of ‘hammerheads’ caught, rather than giving the numbers of each species caught. This means there is limited information on the actual number of each of these threatened species caught in Australian waters.

 

Threats to Hammerhead Sharks

Commercial Fishing

Commercial fishing is the biggest threat to hammerheads, with 370t of hammerhead sharks legally allowed to be caught every year in Australian waters (1).

How are people getting away with fishing hammerhead sharks?

The trade in these species is regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) convention. Australia is a signatory to the convention.

Any trade of CITES listed species must conform to a Non-Detriment Finding (NDF) which contains management guidelines to ensure the species survival is not threatened by trade. An NDF is a decision and report made by the Federal Government using information provided by an independent and objective scientific assessment of CITES listed species.

AMCS questions the findings in the NDF report that the current levels of hammerhead harvest are sustainable and instead recommends a more precautionary approach that restricts catch and prohibits export in light of:

  • The lack of scientific data on population numbers, population range and impacts from outside Australian waters.
  • Uncertainty around the numbers of hammerheads currently killed in Australian fisheries due to lack of reporting to species level, lack of bycatch reporting and possible illegal and unreported fishing.
  • The globally endangered or vulnerable conservation status of the species.
  • The life history characteristic of hammerheads (long lived, late maturing with few offspring) making them slow to recover from excessive fishing pressure.

 

Shark Culling

Hammerhead sharks are also threatened by culling through lethal shark control programs. In six years (2012-2018), 592 hammerheads sharks have been culled at an average of 99 per year (6).

Hammerhead sharks have never been involved in a fatal incident. Since 1937 in NSW and 1962 in QLD, lethal shark control programs have been carried out each year using either nets or drumlines. These methods are outdated and ineffective – in 2006 a fatal shark bite occurred on a drumlined beach in Amity Point, QLD (7).

 

References:
  1. Dept. of Environment and Energy (2014) “Non-Detriment Finding for the export of shark species listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and harvested from Australian waters”, Australian Government, Canberra.
  2. Simpfendorfer, C (2014) “Information for the development of Non Detriment Findings for CITES listed sharks”, James Cook University, QLD.
  3. http://www.iucnredlist.org/details/39385/0
  4. http://www.iucnredlist.org/details/39386/0
  5. https://www.dpi.nsw.gov.au/fishing/species-protection/hammerhead-sharks-faq
  6. Compiled data from QLD and NSW shark control programs. For NSW, see https://www.dpi.nsw.gov.au/fishing/sharks/management/shark-meshing-bather-protection-program For QLD, see https://data.qld.gov.au/dataset/shark-control-program-shark-catch-statistics
  7. Taronga Zoo’s Shark Attack File https://taronga.org.au/conservation-and-science/australian-shark-attack-file