Australian Sea Lions

Threatened Status:

  • Listed as Endangered (EPBC Act – Australian )
  • Endangered (IUCN – global rating)


South Australia and Western Australia coastlines

Australian sea lions are a type of pinniped (seals, sea lions and walruses) that are only found on our shores.

These beautiful animals live in colonies made up of small populations along the coastline of South Australia (SA) and Western Australia (WA). Historically hunted for their fur, Australian sea lion numbers have fallen by over 60% in four decades and are at such low levels that in 2021 the species was re-assessed and listed from ‘vulnerable’ to ‘endangered’ under Australian law.

Quick Facts about Australian Sea Lions

  • Sea lions typically live for 12 years
  • Breeding cycles happen only once every 18 months and female will only breed at the site where they were born
  • Breeding colonies are located only on remote areas of the coastline or islands and only 66 breeding colonies are known
  • Estimated known population of sea lions is around 6500
  • Population numbers are not growing and Australia sea lions are not expanding their range of colonies
  • At 60% of breeding colonies, fewer than 25 sea lion pups are born annually and this number continues to decline
  • Each sea lion colony is genetically distinct from neighbouring colonies and other populations
  • The death of even a single female can have a negative impact on a colony’s survival, especially if the colony has a very low population

Threats to Australian Sea Lions

Currently, the biggest threat to Australia sea lion colonies are gillnets, which are invisible, thin mesh nets suspended in the water. Gillnets are used by commercial fisheries to capture sharks, predominantly for the ‘flake’ and chip market in Australia. However, Australian sea lions also get snagged in the mesh of gillnets and drown. The only solution to accidental gillnet deaths and other fishery-related deaths of sea lions is to close the areas where sea lions forage for food out at sea, and prevent fishing with gillnets in those areas.

South Australian Case Study

The distribution of Australia sea lion colonies in SA overlaps with a fishery managed by the Federal Government agency, the Australian Fisheries Management Authority (AFMA). Due to the close proximity between the fishery and sea lion colonies, fishing was killing a high number of sea lions.

In 2010, scientists published a report that found up to 374 Australia sea lions were killed in the fishery every 18 months. This report also indicated that this rate of fishery-induced deaths was too high for the sea lion populations to withstand – bringing Australian sea lions closer to extinction. In addition, commercial fishers were not reporting how many sea lions were being killed to AFMA, so the true cost of fishing to the species was hidden.

AMCS worked with the government, scientists and the fishing industry to come up with a solution to ensure sea lion colonies were protected, only brought about by the support of the Australian public.

The areas of sea directly around sea lion breeding colonies are closed to gillnet fishing, and now, every fishing boat that fishes anywhere near sea lion colonies has to have cameras on board to monitor what is being caught. This means that if a sea lion gets killed, it now gets reported to AFMA. And when a sea lion does get killed, further areas are closed to all gillnet fishing to ensure sea lion colonies do not decline even further.

This means that through the activity of AMCS, our wonderful supporters and other environmental organisations, potentially hundreds of vulnerable Australian sea lions have been protected from drowning in this fishery.

Western Australian Case Study

Similarly to SA, a shark fishery in WA overlaps with Australian sea lion colonies around the WA coastlines. The fishery uses gillnets to target sandbar, whiskery and dusky sharks. But unlike SA, there is even less known about the sea lion populations in WA. The colonies are smaller, and are therefore at even more risk from fishing deaths. It is estimated that three of the colonies have less than 10 females.

Fishing boats in the SA fishery are subject to 100% observer coverage – so sea lion deaths are reported. By contrast, observer coverage in the WA fishery is currently non-existent. Although fishers have reported low levels of interaction with Australian sea lions, it is hard to have confidence these are a true indication of the real numbers of deaths. Not only is the WA Australian sea lion population likely to be more at risk than in SA, the regulation and monitoring of interactions is far worse.

Thousands of AMCS supporters wrote to the WA Fisheries Minister asking him to ensure Australian sea lions were protected from fishing in WA. In 2018, the WA Government established sea lion protection zones around breeding colonies, areas where no fishing with gillnets is permitted. This should help protect this vulnerable species from drowning in gillnets in future.


  1. Goldsworthy, B Page, PD Shaughnessy, A Linnane (2010) – Mitigating Seal Interactions in the SRLF and the Gillnet Sector SESSF in South Australia
  2. Goldsworthy, S.D. (2020). Australian sea lion listing assessment. Report to the Department for Environment and Water, Department of Agriculture, Water and the Environment. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2020/000131-1. SARDI Research Report Series No. 1056.,_Department_of_Agriculture,_Water_and_the_Environment.pdf
  3. Senate Hansard, Environment Protection and Biodiversity Conservation Amendment (Standards and Assurance) Bill 2021, 4 May 2021, via