Taking stock of Australia’s most threatened fishes
In a new study, a team of freshwater fish experts identify the 22 species at greatest risk of extinction. We spoke with lead author Mark Lintermans about his findings.
A pair of Daintree rainbowfish, Cairnsichthys bitaeniatus, one of Australia’s most endangered freshwater fishes. © Michael Hammer
Australia is home to more than 300 native freshwater fishes, from the mighty Murray cod to the miniscule red-finned blue-eye. Sadly, almost one-fifth of these species are threatened with extinction due to human activities. In a new study, a team of freshwater fish experts identified the 22 freshwater fish species at greatest risk of extinction.
Surprisingly, most of these imperilled species are not yet listed as threatened under the Australian Government’s Environment Protection and Biodiversity Conservation (EPBC) Act 1999, and, as a result, are unlikely to receive conservation funding. Experts fear that many will go extinct within 20 years without urgent intervention.
We spoke with lead author Mark Lintermans about his findings.
What was the impetus for this workshop and review paper?
ML: The impetus for this work arose from a workshop series I ran through the ASFB Threatened Fishes Committee between 2014 and 2018, to review which freshwater fish species needed prioritising for formal assessment for listing on the ASFB threatened fishes list. I had been agitating nationally that fish were generally overlooked in national threatened species programs: the Federal Government’s EPBC Act only lists 38 freshwater species, whereas the ASFB list had more than 60, and the National Threatened Species Strategy identifies priority mammals, birds and plants, but no fish. The publication of a paper identifying the most threatened birds and mammals spurred me to contact the Threatened Species Hub (who did the mammal and bird paper) to see whether we could do something similar for freshwater fishes.
Mark Lintermans, pictured at the 2016 ASFB conference in Hobart, Tasmania. Andrew Katsis (CC BY-SA 4.0)
When was the workshop?
ML: The workshop was in Melbourne in March 2018. (But I then got totally derailed by organising the IUCN Red List assessment of all Australian freshwater fishes, which consumed the second half of 2018 and all of 2019, and which was published in December 2019).
Were you surprised by anything you found in this review?
ML: The surprising thing was how the experts considered freshwater fish to be so much more threatened than the birds or mammals. Only nine of 20 birds and 1 of 20 mammals likely to go extinct in the next 20 years were considered to have >50% chance of extinction in the next 20 years, whereas 19 of 22 fish had >50% likelihood of extinction. This is an astounding result and highlights the urgent need for recovery actions and increased public awareness of the plight of freshwater fish.
Holotype specimen of the critically endangered Swan galaxias, Galaxias fontanus, first described in 1978. Tasmanian Museum and Art Gallery/Fishes of Australia (CC BY-NC-SA)
Many of these species are rarely seen and/or have highly restricted ranges. Why is it important to conserve them?
ML: Probably the majority of small-bodied fish are rarely seen and that is one of the great challenges in freshwater fish conservation, particularly for rare or threatened species. Being underwater and out of sight means they are also out of mind for the public (i.e. not thought about much). It is the charismatic large fish (Murray cod, barramundi, lungfish) that capture public attention, and even that attention is at a much lower level than for the furred or feathered beasties such as cassowaries, koalas, Leadbeater’s possums and platypuses.
The threatened fishes’ highly restricted ranges are largely an artefact of the threats they face, with ranges greatly reduced as a result of those threats. For example, stocky galaxias (Galaxias tantangara) has conservatively lost 98% of its range as a result of impacts from trout. I want my grandchildren and their grandchildren to be able to see this species in the wild, and I believe if we have the capacity to conserve and restore these species then why wouldn’t we? I certainly don’t want fish to go extinct on my watch.
The critically endangered East Gippsland galaxias, Galaxias aequipinnis, was not formally described until 2014. Raadik (2014) (CC BY)
Is there anything that non-researchers can do to support Australia's freshwater fishes?
ML: The most important thing that non-researchers can do is raise the awareness of the plight of freshwater fish and the need to conserve our aquatic habitats. And don’t just focus on the large charismatic species that are recreationally important (Macquarie perch, Murray cod, silver perch), which are usually the public focus of fish conservation or angst. The little fellas are really in deep trouble: they are “underwater, out of sight, out of mind” and will rarely be encountered by the public. When I talk to people about threatened fauna, I say “If you’ve got fur or feathers, you’re fine. If you’ve got fins, you’re f***** [forgotten]”.
As far as freshwater fish are concerned, we are currently losing the battle against extinction. But there is room for hope if we take immediate action. Species such as the Pedder galaxias (Galaxias pedderensis) and barred galaxias (Galaxias fuscus) would already be extinct if not for the dedicated efforts of scientists, river managers and fish enthusiasts. One critically endangered species, the Running River rainbowfish (Melanotaenia sp.), only survives thanks to an eleventh-hour captive breeding and reintroduction program that began in 2016, funded by donations from aquarium hobbyists.
Despite these modest successes, the status quo will not be enough to preserve our freshwater biodiversity. "The probability of further extinctions of Australian freshwater fishes in the next two decades is extraordinarily and unacceptably high,” write Lintermans and his co-authors. “Only urgent action, enhanced policy, and increased community awareness will prevent this from happening."
Australia’s 22 most threatened freshwater fishes, as determined by a panel of experts. “AOO” refers to the species’ current area of occupancy. Lintermans et al. (2020)
This new study, published in the journal Pacific Conservation Biology, drew heavily on the ongoing work of the ASFB’s Threatened Fishes Committee, which maintains a regularly updated list of Australia’s threatened fishes. The committee has been active since the 1980s, and is currently convened by Michael Hammer, a taxonomist at the Museum and Art Gallery of the Northern Territory.
Written by Andrew Katsis, ASFB Communications Manager