New study refocusses fish conservation efforts – Introduced fish biggest threat to native species

Posted at 29 Nov 2024 at 20:12h in News, Fish, Fish conservation, Research, Threatened Species Conservation by
0 Likes

Fifty-two top native fish experts from across the country including Sylvia Zukowski (NGT), Nick Whiterod, Michael Hammer and Maiko Lutz (ex-NGT), have banded together to complete the nation’s first comprehensive national freshwater fish assessment. They used the International Union for Conservation of Nature (IUCN) criteria to assess 241 species of native freshwater fish. They found that 88 species (37% of those assessed) were threatened, and identified 35 species that should be added to the threatened species list under the national Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), which currently contains 63 freshwater fish species. They also identified one species likely to be extinct, three species that should be down-listed as their population had recovered somewhat, and pleasingly one species (The iconic Murray Cod), has recovered enough to be considered for de-listing.

Figure from the Biodiversity Council. Fact Sheet below: “A map of extinction risks across Australia with examples of fish at risk and their IUCN Red List category. Red areas have high risk of their native species becoming extinct. White areas have a low risk. Pink is moderate. Fish images clockwise from top left: Michael Hammer, ANGFA Qld, Brett Vercoe, Steven Kuiter, Inland Fisheries Service, Gerald R Allen, Michael Hammer. Overall figure: M. Lintermans, N. Whiterod and J. Dielenberg.”

The study, titled “Troubled waters in the land down under: Pervasive threats and high extinction risks demand urgent conservation actions to protect Australia’s native freshwater fishes” was published in the leading international Journal of Biological Conservation. Click here to see the article abstract.

The top three drivers of native freshwater fish decline were identified as:

  • invasive fish – which threaten 92% of freshwater fish species of conservation concern and include introduced species such as trout (Brown and Rainbow – which are still deliberately released into the wild in high numbers each year for recreational fishing), Redfin Perch and Gambusia (mosquitofish)
  • natural system modifications – e.g. habitat loss and modification like removing fallen timber from rivers, damming rivers, water extraction and changes to flow.
  • climate change and extreme weather – e.g. extreme droughts and floods, and bushfires.
    Figure (right) from The Biodiversity Council Fact Sheet (Preventing extinctions of Australian freshwater fishes: A national assessment. Research findings, Nov 2024)

The nationally significant publication had coverage on various news outlets including an article on ABC news (“Freshwater fish survey calls for 35 new threatened listings“) and in The Conversation (“Troubled waters: How to stop Australia’s freshwater fish species from going extinct“).

Finally, below is a fact sheet summarising the study, put together by the Biodiversity Council (Preventing extinctions of Australian freshwater fishes: A national assessment. Research findings, Nov 2024)

FACTSHEET_Freshwater_fish_risk_assessment_Nov2024_a3718cb98b

Tessa Roberts