Immediate Genetic Augmentation and Enhanced Habitat Connectivity Are Required to Secure the Future of an Iconic Endangered Freshwater Fish Population DOI Creative Commons
Alexandra Pavlova,

Luke Pearce,

Felicity Sturgiss

et al.

Evolutionary Applications, Journal Year: 2024, Volume and Issue: 17(10)

Published: Oct. 1, 2024

ABSTRACT Genetic diversity is rapidly lost from small, isolated populations by genetic drift. Measuring the level of drift using effective population size ( N e ) highly useful for management. Single‐cohort estimators approximate number breeders in one season b ): a value < 100 signals likely inbreeding depression. Per‐generation 1000 estimated multiple cohort reduced adaptive potential. Natural rarely meet assumptions ‐estimation, so interpreting estimates challenging. Macquarie perch an endangered Australian freshwater fish threatened severely range, habitat loss, and fragmentation. To counteract low , augmented gene flow being implemented several populations. In Murrumbidgee River, unknown effects water management on among‐site connectivity impede design interventions. Using DArT SNPs 328 individuals sampled across sites years with different conditions, we assessed structure, site isolation, heterozygosity, inbreeding, . We tested depression, dispersal, evaluated whether translocated Cataract Reservoir to River bred, interbred local fish. found strong indicating complete or partial isolation river fragments. This structure violates estimation, resulting strongly downwardly biased unless per‐site, highlighting necessity account while estimating Inbreeding depression was not detected, but at each site, are likely. These results flagged address within‐river through mixing translocations among other Three detected genetically diverse offspring parent indicated that progress. Including admixed yielded lower higher suggesting heterozygosity preferable indicator augmentation.

Language: Английский

Planning and implementing genetic rescue of an endangered freshwater fish population in a regulated river, where low flow reduces breeding opportunities and may trigger inbreeding depression DOI Creative Commons
Alexandra Pavlova, Nadja M. Schneller, Mark Lintermans

et al.

Evolutionary Applications, Journal Year: 2024, Volume and Issue: 17(4)

Published: April 1, 2024

Abstract Augmenting depleted genetic diversity can improve the fitness and evolutionary potential of wildlife populations, but developing effective management approaches requires genetically monitored test cases. One such case is small, isolated inbred Cotter River population an endangered Australian freshwater fish, Macquarie perch Macquaria australasica , which over 3 years (2017–2019) received 71 translocated migrants from a closely related, more diverse population. We used monitoring to whether immigrants bred, interbred with local fish augmented diversity. also investigated levels river flow affected recruitment, inbreeding depression juvenile dispersal. Fish length was estimate age, birth year cohort growth 524 individuals born between 2016 2020 under variable conditions. DArT genome‐wide genotypes were assess individual ancestry, heterozygosity, short‐term size identify parent‐offspring full‐sibling families. Of 442 after translocations commenced, only two (0.45%) mixed ancestry; these half‐sibs one parent in common. Numbers breeders for five cohorts low, especially low‐flow years. Additionally, lowest evidently suffered growth. The highest associated largest number breeders, offspring greatest dispersal distances. Genetic decreased upstream direction, flagging restricted access most breeding sites, exacerbated by low flow. Our results suggest that effectiveness could be increased focussing on sites moving per year; using riverine sources should considered. indicate sufficient facilitate movement through system would increase promote individuals' growth, reduce rescue.

Language: Английский

Citations

4
Sexual selection matters in genetic rescue, but productivity benefits fade over time: a multi-generation experiment to inform conservation DOI Creative Commons
G. S. West, Michael D. Pointer, Will Nash

et al.

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 292(2039)

Published: Jan. 1, 2025

Globally, many species are threatened by population decline because of anthropogenic changes leading to fragmentation, genetic isolation and inbreeding depression. Genetic rescue, the controlled introduction variation, is a method used relieve such effects in small populations. However, without understanding how characteristics rescuers impact rescue attempts interventions run risk being sub-optimal, or even counterproductive. We use red flour beetle ( Tribolium castaneum ) test rescuer sex, sexual selection background, on productivity. record productivity 24 36 replicated populations for ten generations following intervention. find little no sex efficacy but show that background elevated makes individuals more effective rescuers. In both experiments, diminish 6–10 after rescue. Our results confirm can be influenced level rescuing an important factor. any increase fitness associated with may last limited number generations, suggesting implications conservation policy practice.

Language: Английский

Citations

0
Otolith and Genomic Data Reveal Temporal Insights Into Stocking Across a Large River Basin in a Mobile, Long‐Lived Australian Freshwater Fish Species DOI Creative Commons
Katherine A. Harrisson, Luciano B. Beheregaray, Christopher M. Bice

et al.

Molecular Ecology, Journal Year: 2025, Volume and Issue: unknown

Published: March 5, 2025

Freshwater ecosystems and their biota are under increasing pressure from anthropogenic stressors. In response to declining fish stocks, hatchery stocking programmes widely implemented as core components of restoration management strategies, with positive outcomes for some wild populations. Despite this, remains contentious due potential genetic ecological risks Monitoring evaluation critical ensuring the long-term sustainability populations, but identification stocked individuals post-release a key challenge, particularly mobile species. this study, we combined otolith (natal origin age) genomic data identify evaluate implications culturally socioeconomically important freshwater fish, golden perch Macquaria ambigua (family: Percichthyidae), across Australia's Murray-Darling Basin (MDB). We also generated chromosome-level genome assembly. Many close kin were detected MDB, in prevalence over recent decades mostly origin. Rivers many associated low effective population sizes (Ne < 100). Genetic signatures varied according local context, being most pronounced not restricted rivers considered functionally isolated purposes. Where into that part connected metapopulation, there is scope modify current practices avoid over-representation related individuals. Increased focus on diversity likely promote persistence wild.

Language: Английский

Citations

0
Genomes of critically endangered saola are shaped by population structure and purging DOI Creative Commons
Genís Garcia‐Erill, Shanlin Liu, Minh Đức Lê

et al.

Cell, Journal Year: 2025, Volume and Issue: unknown

Published: May 1, 2025

The saola is one of the most elusive large mammals, standing at brink extinction. We constructed a reference genome and resequenced 26 individuals, confirming as basal member Bovini. Despite its small geographic range, we found that partitioned into two populations with high genetic differentiation (FST = 0.49). estimate these diverged started declining 5,000-20,000 years ago, possibly due to climate changes exacerbated by increasing human activities. has long tracts without genomic diversity; however, are not shared populations. Saolas carry load, yet their gradual decline resulted in purging deleterious variation. Finally, find combining populations, e.g., an eventual captive breeding program, would mitigate load increase odds species survival.

Language: Английский

Citations

0
Immediate Genetic Augmentation and Enhanced Habitat Connectivity Are Required to Secure the Future of an Iconic Endangered Freshwater Fish Population DOI Creative Commons
Alexandra Pavlova,

Luke Pearce,

Felicity Sturgiss

et al.

Evolutionary Applications, Journal Year: 2024, Volume and Issue: 17(10)

Published: Oct. 1, 2024

ABSTRACT Genetic diversity is rapidly lost from small, isolated populations by genetic drift. Measuring the level of drift using effective population size ( N e ) highly useful for management. Single‐cohort estimators approximate number breeders in one season b ): a value < 100 signals likely inbreeding depression. Per‐generation 1000 estimated multiple cohort reduced adaptive potential. Natural rarely meet assumptions ‐estimation, so interpreting estimates challenging. Macquarie perch an endangered Australian freshwater fish threatened severely range, habitat loss, and fragmentation. To counteract low , augmented gene flow being implemented several populations. In Murrumbidgee River, unknown effects water management on among‐site connectivity impede design interventions. Using DArT SNPs 328 individuals sampled across sites years with different conditions, we assessed structure, site isolation, heterozygosity, inbreeding, . We tested depression, dispersal, evaluated whether translocated Cataract Reservoir to River bred, interbred local fish. found strong indicating complete or partial isolation river fragments. This structure violates estimation, resulting strongly downwardly biased unless per‐site, highlighting necessity account while estimating Inbreeding depression was not detected, but at each site, are likely. These results flagged address within‐river through mixing translocations among other Three detected genetically diverse offspring parent indicated that progress. Including admixed yielded lower higher suggesting heterozygosity preferable indicator augmentation.

Language: Английский

Citations

0