Threats to Fur-seals & Sea Lions in South Australia

The main predators of pinnipeds (mammals with flippers) are sharks. In South Australia there are always Great White Sharks in the waters around fur-seal or sea-lion colonies.

The greatest threat to the survival of fur-seals and sea-lions is people. The days of the sealers are gone forever, but humans pose threats in many other ways:

• Accidental by-catch by some fisheries and aquaculture operations
• Marine habitat destruction (e.g. trawling coastal development)
• Litter
• Gill nets and "ghost fishing" by lost and discarded gear
• Human intervention such as feeding
• Illegal shooting
• Some Fishing practices
• Entanglement in marine debris

You can also view the DEWHA threat abatement plan (PDF 168Kb) for the impacts of marine debris on threatened species (listed under EPBC). The plan and the background document (PDF 377Kb) are available for public comment. SADEH and SARDI reviewed an earlier draft and recommended that the impact of marine debris on Australian sea lions be addressed in this Plan. The plan does not formally address the issues that affect sea lions, except that:

• Although not specifically identified by the TSSC in the listing of harmful marine debris as a key threatening process, a number of other species are impacted by harmful marine debris (Table 2.2). For example, populations of Australian sea lions have been impacted by harmful debris (Robinson and Dennis, 1988; Shaughnessy, 1999; Gibbs, 2000; Shaughnessy et al., 2003; Page et al., 2004) but were not specifically identified by the TSSC. As these species are not included in the key threatening process listing, they are not specifically addressed by the threat abatement plan
• Sea lions are one of the few Australian threatened species that have been shown to be negatively affected by marine debris, to the point that it may be slowing their population recovery. SARDI and SADEH will again provide input on this Plan.
  

For more information about threats to fur-seals and sea-lions:

Teacher resource: Diving Through Debris

Report: Understanding the impediments to the growth of Australian sea lion populations