Biodiversity

Biodiversity continued to decline, with fire, drought and heat all impacting on ecosystems.

Another 15 species were added to the Threatened Species List and 3 removed. This represents a 0.6% increase from the previous year and a 36% increase from 2000.

A total of 1902 species are now listed. Plants make up 72% of threatened species, and have declined on average by 70% since 2000.

Number of species on Threatened Species List (Commonmwealth Dept. of Agriculture, Water and the Environment, DAWE)
Number of species on Threatened Species List (Commonmwealth Dept. of Agriculture, Water and the Environment, DAWE)

The 2019/20 Black Summer bushfire season had a major impact on threatened ecosystems and species in southeast Australia. The immediate impact of the fires and the food shortage afterwards were compounded by predators, especially feral cats.

The fires burnt through more than 5% of the habitat of 249 threatened species, and more than 80% for 30 species.

Three species were down-listed, 15 added and four up-listed. Among the downlisted species were two tropical tree frog species that appear to have rebounded from the global chytrid fungus disease.

Number of threatened species impacted and percentage of range burnt (DAWE)
Number of threatened species impacted and percentage of range burnt (DAWE)

No species were declared extinct, however the impacts of the bushfires is expected to result in new extinctions being declared in 2021.

Two species thought extinct were rediscovered and taxonomic changes added two new mammal species. Another 30 new marine species were described following exploration in deep sea canyons off West Australia.

Arid zone bird species such as the budgerigar were found migrating across NSW and South Australia following good rains in those areas.

The full impacts of the fires on biodiversity will not be known for some time. The COVID-19 pandemic has further hampered monitoring efforts. In some cases, there are encouraging signs. Citizen scientists found all 33 summer-breeding frogs in the fire-affected areas, including several threatened species. The endangered Mt Kaputar pink slug also survived as a species.

Waterbird numbers in inland southeastern Australia showed a decrease from the previous year and remained lower than the long-term average for the eighth year in a row. This is consistent with continued low levels of wetland inundation.

Regrowth from fire-tolerant eucalyptus trunks after the Black Summer fires (Image: Nathan Rott/NPR)
Common mist frog (Litoria rheocola), one of the species recovering from chytrid fungus disease.
The endangered Mt Kaputar pink slug survived the fires (Michael Murphy / NPWS )