Reversing the decline of threatened koala (Phascolarctos cinereus) populations in New South Wales: Using genomics to enhance conservation outcomes

• Published in: Ecology and evolution Vol. 14; no. 8; pp. e11700 - n/a
• Main Authors: Lott, Matthew J., Frankham, Greta J., Eldridge, Mark D. B., Alquezar‐Planas, David E., Donnelly, Lily, Zenger, Kyall R., Leigh, Kellie A., Kjeldsen, Shannon R., Field, Matt A., Lemon, John, Lunney, Daniel, Crowther, Mathew S., Krockenberger, Mark B., Fisher, Mark, Neaves, Linda E.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.08.2024; John Wiley and Sons Inc; Wiley
• Subjects: Anthropogenic factors; Biodiversity; Biodiversity loss; Climate change; Conservation Genetics; conservation genomics; Critical components; Environmental protection; Gene flow; Genetic diversity; Genomes; Genomics; Habitats; Nucleotides; Phascolarctos cinereus; phylogeography; Population; Population decline; Population genetics; Populations; Single-nucleotide polymorphism; Threat evaluation; Threatened species; threatened species management; Threats; Translocation; Wildlife conservation; wildlife monitoring; Australia; New South Wales Australia; wildlife monitoring; Phascolarctos cinereus; threatened species management; conservation genomics; phylogeography
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.11700

Genetic management is a critical component of threatened species conservation. Understanding spatial patterns of genetic diversity is essential for evaluating the resilience of fragmented populations to accelerating anthropogenic threats. Nowhere is this more relevant than on the Australian continent, which is experiencing an ongoing loss of biodiversity that exceeds any other developed nation. Using a proprietary genome complexity reduction‐based method (DArTSeq), we generated a data set of 3239 high quality Single Nucleotide Polymorphisms (SNPs) to investigate spatial patterns and indices of genetic diversity in the koala (Phascolarctos cinereus), a highly specialised folivorous marsupial that is experiencing rapid and widespread population declines across much of its former range. Our findings demonstrate that current management divisions across the state of New South Wales (NSW) do not fully represent the distribution of genetic diversity among extant koala populations, and that care must be taken to ensure that translocation paradigms based on these frameworks do not inadvertently restrict gene flow between populations and regions that were historically interconnected. We also recommend that koala populations should be prioritised for conservation action based on the scale and severity of the threatening processes that they are currently faced with, rather than placing too much emphasis on their perceived value (e.g., as reservoirs of potentially adaptive alleles), as our data indicate that existing genetic variation in koalas is primarily partitioned among individual animals. As such, the extirpation of koalas from any part of their range represents a potentially critical reduction of genetic diversity for this iconic Australian species. An enzyme‐based genome complexity reduction method was used to create a data set of high‐quality single nucleotide polymorphisms (SNPs) to investigate spatial patterns and indices of genetic diversity in koalas across established management divisions in the state of New South Wales (NSW). Our results indicate that contemporary management divisions do not fully reflect the distribution of genetic diversity among threatened koala populations, and that care must therefore be taken to ensure that pre‐existing conservation frameworks do not artificially restrict gene flow between previously interconnected regions.