Long-term Genetic Monitoring Research Articles

Estimating the Effective Size of European Wolf Populations.

Molecular methods are routinely used to estimate the effective size of populations (N e). However, underlying model assumptions are frequently violated to an unknown extent. Although simulations can detect sources of bias and help to adjust sampling strategies and analyses methods, additional information from empirical data can also be used to calibrate methods and improve molecular N e estimation methods. Here, we take advantage of long-term genetic and ecological monitoring data of the grey wolf (Canis lupus) in Germany, and detailed population genetic studies in Poland, Spain and Portugal to improve N e estimation strategies in this species, and species with similar life history traits. We first calculated N e from average lifetime reproductive success and detailed census data from the German population, which served as a baseline to compare to molecular estimates based on linkage disequilibrium and sibship frequency. This yielded a robust N e/N c estimation that we used to calibrate molecular estimates of German, Polish and Iberian wolf populations. The linkage disequilibrium method was strongly influenced by spatial genetic structure, much more than the sibship frequency method. When N e was estimated in local neighbourhoods, both methods yielded comparable results. Estimates of the metapopulation effective size seemed to correspond generally well with the sum of the estimates of local neighbourhoods. Overall, we found that the number of packs is a good proxy of the effective population size. Using this as a rule of thumb, we evaluated for all European wolf populations the N e 500 indicator and concluded that half of the European wolf populations do not yet fulfil this criterion.

Molecular analysis of scats revealed diet and prey choice of grey wolves and Eurasian lynx in the contact zone between the Dinaric Mountains and the Alps

A comprehensive understanding of the dietary habits of carnivores is essential to get ecological insights into their role in the ecosystem, potential competition with other carnivorous species, and their effect on prey populations. Genetic analysis of non-invasive samples, such as scats, can supplement behavioural or microscopic diet investigations. The objective of this study was to employ DNA metabarcoding to accurately determine the prey species in grey wolf (Canis lupus) and Eurasian lynx (Lynx lynx) scat samples collected in the Julian Alps and the Dinaric Mountains, Slovenia. The primary prey of wolves were red deer (Cervus elaphus) (detected in 96% scat samples), European roe deer (Capreolus capreolus) (68%), and wild boar (Sus scrofa) (45%). A smaller portion of their diet consisted of mesocarnivores, small mammals, and domestic animals. In contrast, the lynx diet mostly consisted of European roe deer (82%) and red deer (64%). However, small mammals and domestic animals were also present in lynx diet, albeit to a lesser extent. Our findings indicate that the dietary habits of wolves and lynx are influenced by geographical location. Snapshot dietary analyses using metabarcoding are valuable for comprehending the behaviour and ecology of predators, and for devising conservation measures aimed at sustainable management of both their natural habitats and prey populations. However, to gain a more detailed understanding of wolf and lynx dietary habits and ecological impact, it would be essential to conduct long-term genetic monitoring of their diet.

Changes in the spatio-temporal genetic structure of Baltic sea trout (Salmo trutta L.) over two decades: direct and indirect effects of stocking

Several countries have implemented stocking programmes to enhance abundance and fish production by releases of hatchery-reared fish. However, due to fluctuations in population size, stocking history, and potential indirect effects of straying of hatchery-reared fish, it is often difficult to predict how these factors will affect genetic diversity and differentiation patterns among wild populations. This study characterized the population genetic structure and temporal variability of four Estonian sea trout populations by evaluating the degrees of direct and indirect genetic impacts of stocking over two decades using 14 microsatellite loci. Our results demonstrate considerable temporal change combined with weak genetic structuring among studied sea trout populations. We found a reduction of the overall level of genetic differentiation combined with the tendency for increased genetic diversity, and an effective number of breeders (Nb) over the study period. Furthermore, we found that immigration rates (m) from hatchery stocks were highest in the population subjected to direct stocking and in non-stocked populations that were located geographically closer to the stocked rivers. This work suggests that hatchery releases have influenced the genetic diversity and structuring of studied sea trout populations. However, the impact of hatchery releases on the adaptive variation and fitness-related traits in wild trout populations remains to be revealed by more informative genetic markers. This study illustrates the dynamic nature of the population genetic structure of sea trout and the value of long-term genetic monitoring for management and conservation.

Towards a standardised set of data analyses for long-term genetic monitoring of grouse using non-invasive sampling: a case study on western capercaillie

Genetic monitoring has become a popular instrument in the conservation of endangered species, allowing to estimate size and genetic structure of wild populations. Long-term monitoring projects are essential to recognize demographic changes and impact of human activities. Since 2011, an extensive monitoring project on the population size and trends, as well as spatial distribution and survival rates, of two grouse species including the western capercaillie, Tetrao urogallus, has been conducted in Tyrol, in the eastern part of the European Alps, where T. urogallus males are huntable under specific regulations. In this case study, we aimed to compile a set of analyses to be employed in evaluating data from dropping and feather samples for conservation studies. Using eleven microsatellite and two sex markers, we genotyped 251 faeces and feathers of T. urogallus collected in East Tyrol in spring 2019. We analysed population structure and mobility patterns, including sex differences in genetic diversity and mobility. The relationship between habitat parameters and genetic diversity was investigated using multiple linear regressions. We showed that the investigated T. urogallus population is well mixed and likely well connected to neighbouring populations. We also found sex-specific mobility patterns that support female-biased dispersal. As the last step, we demonstrated the general feasibility of a modelling approach using habitat parameters. With this pilot study, further analysis of data is possible for the whole monitoring project, giving a better insight in the grouse populations in Tyrol.

Translocation precipitates natural hybridisation and pervasive introgression between marine gastropods with divergent developmental modes

Assisted colonisation, the introduction of species beyond their historical range, is increasingly necessary for conserving species. However, empirical evidence of the long-term genetic outcomes of assisted colonisation is grossly lacking. A risk associated with moving species beyond their native range is the possibility of interspecific hybridisation with a closely related species, potentially resulting in outbreeding depression or the genetic swamping of a parental species. Here, we use a combination of genome-wide Single Nucleotide Polymorphism (SNP) markers and mitochondrial DNA sequencing to determine the long-term genetic consequences of introducing the intertidal periwinkle Bembicium vittatum (a direct developer) beyond its native range and into the native range of its congener Bembicium auratum (a species with planktotrophic larval dispersal). We found novel evidence of natural, multigenerational hybridisation between marine invertebrates with different modes of development. Intriguingly, introgression was highly asymmetrical initially, but became more evenly bidirectional as the population became more admixed. There was a significant decline in the frequency of alleles from the introduced B. vittatum over time, providing evidence of genetic swamping. The present study also provides potential evidence of outbreeding depression, in the form of cytonuclear incompatibilities, leading to the observed pattern of asymmetrical introgression. This study reveals the potential for unexpected mixing between species when reproductive barriers are not well understood, resulting in failure of pure B. vittatum to persist at the translocation site, a major concern associated with assisted colonisation. Without long-term genetic monitoring interspecific hybridisation between B. vittatum and B. auratum would have gone undetected, highlighting the importance of long-term monitoring to detect unintentional negative consequences of conservation translocations. Successful assisted colonisation requires an understanding of the potential for interspecific hybridisation between the threatened species and closely related native species, to reduce the risk of adverse outcomes.

Long-term genetic monitoring of a reintroduced Eurasian lynx population does not indicate an ongoing loss of genetic diversity

Where reintroduced wildlife populations are considered as vulnerable this is generally due to limited founder size and isolation. While many of these populations show low levels of genetic diversity, little is known about the temporal patterns of genetic diversity loss and the role of initial founder effects vs. ongoing genetic drift. Here we analysed genotype data from 582 Eurasian lynx samples from the reintroduced Bohemian-Bavarian-Austrian population (BBA) over a time span of 35 years, representing approximately 13 generations. Two-wave reintroduction of lynx from at least two distinct West-Carpathian areas resulted in relatively high start-up of genetic diversity. After the initial decline when the population lost about a quarter of its genetic diversity compared to the Carpathian source population, the genetic diversity and effective population size remained almost unchanged over the next 20 years. Despite confirmed isolation of BBA and thus absence of gene flow, we detected relatively low inbreeding during the two recent decades within the slightly increasing population size, which may have prevented ongoing loss of genetic diversity. Given the current status of BBA, we do not support genetic reinforcement to maintain its long-term viability; but urge the importance of facilitating gene flow with neighbouring lynx populations through an improvement of landscape connectivity and by strengthening law enforcement as well as the prevention of illegal killings. A sound genetic monitoring alongside regular camera trap-based monitoring of population size, health status and reproduction is pivotal to decide on future conservation interventions. The genotype data are available within the supplementary material of this article.

Genetic Diversity of Wisent Bison bonasus Based on STR Loci Analyzed in a Large Set of Samples

Wisent Bison bonasus is an example of a species saved from extinction and reintroduced into nature after a few decades of captive breeding. There were only twelve founders of the Lowland–Caucasian line (LC) and even fewer (seven out of twelve) of Lowland (LB) animals. The genetic diversity in studies based on pedigree or markers is very low. In this paper, we present a summary of the long-term genetic monitoring conducted for the worldwide population of European bison. We summarized the long-term genetic monitoring studies conducted on the worldwide population of wisents to date. We genotyped 2227 wisents from two genetic lines (LC and LB) and different populations at ten microsatellite loci. We found low polymorphism, with only 2.7 alleles per locus, and much lower values of observed heterozygosity (0.380 and 0.348 in the LC and LB lines, respectively) than expected heterozygosity. The difference between the lines is only noticeable in allele proportions, so the number of markers is not enough to distinguish the two genetic lines. We also present the genetic distance among four free-roaming populations that are geographically close to each other. We found that the genetic distance of one of them is larger than that of the others, which could be the effect of genetic drift.

Genetic diversity and population structure of Himalayan tahr (Hemitragus jemlahicus) from Western Himalaya

Abstract Himalayan tahr is a group-living animal of high-altitude Himalaya, distributed all across the subalpine range that also formed an important prey base for large carnivores in Himalaya. The species is threatened due to habitat fragmentation, illegal poaching, and anthropogenic activities. We undertook population genetic assessment of Himalayan tahr from Western Himalaya and observed comparable genetic diversity at both mitochondrial and nuclear microsatellite loci. Bayesian skyline plots showed stable demography in the past several thousand years. We identified 27 unique individuals with a select panel of seven loci and the Bayesian structure analysis inferred two genetic clusters. The present study is the first report on the population genetic make-up of Himalayan tahr and can be used for long-term genetic monitoring of the species.

Genetic Diversity of Jinshaia sinensis (Cypriniformes, Balitoridae) Distributed Upstream of the Yangtze River

The upper reaches of the Yangtze River (upper YR) are a biological zone with extremely rich fish diversity, especially endemic fish. However, long-term human interference, such as environmental pollution and cascade hydropower construction, has significantly changed the habitat of many fish and is threatening the number and genetic diversity of fish populations. Jinshaia sinensis is a typical small and endemic but rare fish that is found in the upper YR, and its genetic diversity and structure still need further study. To understand the current levels of genetic diversity in J. sinensis, we analyzed the genetic diversity, population history, genetic structure, etc., of three J. sinensis populations based on two mitochondrial genes (the cytochrome-c oxidase subunit I, COI, and cytochrome-b gene, Cytb) and two nuclear genes (recombination-activating protein 1, RAG1, and rhodopsin, RH). The genetic diversity analysis indicated that J. sinensis had high genetic diversity, with high haplotype diversity (h) and nucleotide diversity (Pi). Population pairwise FST analysis revealed a significant genetic divergence between the Lijiang and Luzhou populations for all genes and between the Panzhihua and Luzhou populations, except for the COI gene; however, analyses of molecular variance (AMOVA) showed no significant geographic genetic structure among populations, and gene flow analysis also indicated a certain degree of gene exchange among populations. Haplotype network structure analyses revealed low levels of shared haplotypes among populations. Neutrality test and mismatch distribution results indicated that only the Lijiang population had experienced obvious population expansion. Overall, these results indicate that J. sinensis is still a single evolutionarily significant unit, but when considering the threat of habitat disturbance to the population, it is still necessary to carry out long-term genetic monitoring on J. sinensis and on other endemic fishes with similar ecological habits in order to maintain the genetic diversity of fishes in the upper YR.

Transitioning from microsatellites to SNP-based microhaplotypes in genetic monitoring programmes: Lessons from paired data spanning 20 years.

Many long-term genetic monitoring programmes began before next-generation sequencing became widely available. Older programmes can now transition to new marker systems usually consisting of 1000s of SNP loci, but there are still important questions about comparability, precision, and accuracy of key metrics estimated using SNPs. Ideally, transitioned programmes should capitalize on new information without sacrificing continuity of inference across the time series. We combined existing microsatellite-based genetic monitoring information with SNP-based microhaplotypes obtained from archived samples of Rio Grande silvery minnow (Hybognathus amarus) across a 20-year time series to evaluate point estimates and trajectories of key genetic metrics. Demographic and genetic monitoring bracketed multiple collapses of the wild population and included cases where captive-born repatriates comprised the majority of spawners in the wild. Even with smaller sample sizes, microhaplotypes yielded comparable and in some cases more precise estimates of variance genetic effective population size, multilocus heterozygosity and inbreeding compared to microsatellites because many more microhaplotype loci were available. Microhaplotypes also recorded shifts in allele frequencies associated with population bottlenecks. Trends in microhaplotype-based inbreeding metrics were associated with the fraction of hatchery-reared repatriates to the wild and should be incorporated into future genomic monitoring. Although differences in accuracy and precision of some metrics were observed between marker types, biological inferences and management recommendations were consistent.

Country-wide genetic monitoring over 21 years reveals lag in genetic recovery despite spatial connectivity in an expanding carnivore (Eurasian otter, Lutra lutra) population.

Numerous terrestrial mammal species have experienced extensive population declines during past centuries, due largely to anthropogenic pressures. For some species, including the Eurasian otter (Lutra lutra), environmental and legal protection has more recently led to population growth and recolonization of parts of their historic ranges. While heralded as conservation success, only few such recoveries have been examined from a genetic perspective, i.e. whether genetic variability and connectivity have been restored. We here use large-scale and long-term genetic monitoring data from UK otters, whose population underwent a well-documented population decline between the 1950s and 1970s, to explore the dynamics of a population re-expansion over a 21-year period. We genotyped otters from across Wales and England at five time points between 1994 and 2014 using 15 microsatellite loci. We used this combination of long-term temporal and large-scale spatial sampling to evaluate 3 hypotheses relating to genetic recovery that (i) gene flow between subpopulations would increase over time, (ii) genetic diversity of previously isolated populations would increase and that (iii) genetic structuring would weaken over time. Although we found an increase in inter-regional gene flow and admixture levels among subpopulations, there was no significant temporal change in either heterozygosity or allelic richness. Genetic structuring among the main subpopulations hence remained strong and showed a clear historical continuity. These findings highlight an underappreciated aspect of population recovery of endangered species: that genetic recovery may often lag behind the processes of spatial and demographic recovery. In other words, the restoration of the physical connectivity of populations does not necessarily lead to genetic connectivity. Our findings emphasize the need for genetic data as an integral part of conservation monitoring, to enable the potential vulnerability of populations to be evaluated.

Genetic Diversity and Population Structure of the Antarctic Toothfish, Dissostichus mawsoni, Using Mitochondrial and Microsatellite DNA Markers

The Antarctic toothfish, Dissostichus mawsoni, serves as a valuable fishery resource around the Antarctic Continent since 1997, managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Although delineating genetic or stock structure of populations is crucial for improving fishery management of this species, its number of genetic populations and genetic diversity levels remain ambiguous. In the present study, we assessed the population genetic and phylogeographic structure of the Antarctic toothfish across 20 geographic localities spanning from Subareas 88 (88.1, 88.2, and 88.3) to Subareas 58 (58.4 and 58.5) by using mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) and 16S rRNA (16S) sequences and seven nuclear microsatellite loci. MtDNA revealed a low level of polymorphism (h = 0.571, π = 0.0006) with 40 haplotypes in 392 individuals, connected only by 1–5 mutational steps, which is indicative of shallow evolutionary history. Microsatellites showed a range of allelic richness (AR) from 6.328 (88.3 RB3) to 7.274 (88.3 RB6) within populations. Overall genetic diversity was generally higher in Subareas 58 than in Subareas 88, suggesting that effective population size (NE) is larger in Subareas 58. The results of population analyses using microsatellites suggest that the sampled populations are likely to comprise a well-admixed single gene pool (i.e., one genetic stock), perhaps due to high contemporary gene flow occurring during the prolonged larval phase of this fish. However, given weak, but significant microsatellite differentiation found in six population-pairs, the possibility of existence of multiple genetic populations could not be completely excluded. The mtDNA AMOVA suggests a genetic break between the Subareas 88 and 58 groups (FCT = 0.011, P = 0.004). Moreover, mtDNA genetic distances (FST) between populations were proportionally greater as geographic distances increase. The patterns of isolation by distance (IBD) shown only in mtDNA, but not in microsatellites might suggest that population differentiation or divergence processes underwent faster in mtDNA than microsatellites, due to its NE being only one-quarter of nuclear DNA. Temporal stability in the genetic structure of D. mawsoni is also indicated by the results of no genetic differentiation between juveniles and adults. The findings of this study will help to design effective stock management strategies for this valuable fishery resource. We suggest that a long-term genetic monitoring is needed to understand the population structure and dynamics of toothfish in response to ongoing climate changes.

Genetic diversity, population structure, and effective population size in two yellow bat species in south Texas.

There are increasing concerns regarding bat mortality at wind energy facilities, especially as installed capacity continues to grow. In North America, wind energy development has recently expanded into the Lower Rio Grande Valley in south Texas where bat species had not previously been exposed to wind turbines. Our study sought to characterize genetic diversity, population structure, and effective population size in Dasypterus ega and D. intermedius, two tree-roosting yellow bats native to this region and for which little is known about their population biology and seasonal movements. There was no evidence of population substructure in either species. Genetic diversity at mitochondrial and microsatellite loci was lower in these yellow bat taxa than in previously studied migratory tree bat species in North America, which may be due to the non-migratory nature of these species at our study site, the fact that our study site is located at a geographic range end for both taxa, and possibly weak ascertainment bias at microsatellite loci. Historical effective population size (NEF) was large for both species, while current estimates of Ne had upper 95% confidence limits that encompassed infinity. We found evidence of strong mitochondrial differentiation between the two putative subspecies of D. intermedius (D. i. floridanus and D. i. intermedius) which are sympatric in this region of Texas, yet little differentiation using microsatellite loci. We suggest this pattern is due to secondary contact and hybridization and possibly incomplete lineage sorting at microsatellite loci. We also found evidence of some hybridization between D. ega and D. intermedius in this region of Texas. We recommend that our data serve as a starting point for the long-term genetic monitoring of these species in order to better understand the impacts of wind-related mortality on these populations over time.

The importance of long-term genetic monitoring of reintroduced populations: inbreeding in the natterjack toad (Epidalea calamita)

Genetic monitoring is an important, but frequently lacking, component of management actions to support long-term persistence in reintroduced populations. Populations that remain small, due to demographic processes and genetic diversity, are more likely to experience a second extinction event. The natterjack toad (Epidelea calamita) is legally protected in Britain and was the subject of a reintroduction programme in the 1990s. However, subsequent genetic assessment has been mostly lacking. The aim of this study was to assess the genetic diversity of two reintroduced populations of natterjack toads in order to inform conservation management. Adults were sampled and nine microsatellites amplified to assess neutral genetic variation within each site and for comparison with the source population. Inbreeding was observed at the reintroduction sites, as evidenced by high FIS values (0.43 and 0.72), low observed compared to expected heterozygosities, and significant deviation from Hardy-Weinberg equilibrium. Observed heterozygosity is currently lower in the reintroduction sites than it was in the source population at the time of the reintroductions (Red Rocks: 0.15±0.20; Talacre: 0.12±0.20; Ainsdale (source): 0.29). Evidence for a bottleneck was not found, although this is likely a result of sampling overlapping generations. No withinsite population structuring was observed. Such low genetic diversity has not previously been recorded in any natterjack population. Genetic rescue, combined with pool creation, is the most viable option for safeguarding the species at these sites into the future. Our work highlights the importance of ongoing genetic monitoring, in collaboration with conservation organisations, to support conservation management.

Spatio-temporal genetic tagging of a cosmopolitan planktivorous shark provides insight to gene flow, temporal variation and site-specific re-encounters

Migratory movements in response to seasonal resources often influence population structure and dynamics. Yet in mobile marine predators, population genetic consequences of such repetitious behaviour remain inaccessible without comprehensive sampling strategies. Temporal genetic sampling of seasonally recurring aggregations of planktivorous basking sharks, Cetorhinus maximus, in the Northeast Atlantic (NEA) affords an opportunity to resolve individual re-encounters at key sites with population connectivity and patterns of relatedness. Genetic tagging (19 microsatellites) revealed 18% of re-sampled individuals in the NEA demonstrated inter/multi-annual site-specific re-encounters. High genetic connectivity and migration between aggregation sites indicate the Irish Sea as an important movement corridor, with a contemporary effective population estimate (Ne) of 382 (CI = 241–830). We contrast the prevailing view of high gene flow across oceanic regions with evidence of population structure within the NEA, with early-season sharks off southwest Ireland possibly representing genetically distinct migrants. Finally, we found basking sharks surfacing together in the NEA are on average more related than expected by chance, suggesting a genetic consequence of, or a potential mechanism maintaining, site-specific re-encounters. Long-term temporal genetic monitoring is paramount in determining future viability of cosmopolitan marine species, identifying genetic units for conservation management, and for understanding aggregation structure and dynamics.

Genetic signatures through space, time and multiple disturbances in a ubiquitous brooding coral

The predominance of self-recruitment in many reef-building corals has fundamental and complex consequences for their genetic diversity, population persistence and responses to climate change. Knowledge of genetic structure over local scales needs to be placed within a broad spatial context, and also integrated with genetic monitoring through time to disentangle these consequences. Here, we examined patterns of genetic diversity over multiple spatio-temporal scales across tropical Australia in the ubiquitous brooding coral, Seriatopora hystrix. We also analysed complimentary environmental and demographic data to elucidate the seascape drivers of these patterns. Large genetic differences were detected between the east vs. west coasts of Australia. In northwest Australia, geographic differentiation dominated genetic structure over multiple scales. However, three sympatric lineages were detected at the largest offshore reef system (Scott Reef). Similar to the differences observed among putative species in eastern Australia, these lineages were associated with different levels of wave exposure. Local genetic structure within the Scott Reef system was relatively stable over 10years, but temporal differences were observed that reflected small but important genetic changes over a few generations during recovery after severe bleaching. These results highlight the importance of self-recruitment together with occasional longer distance connectivity for the persistence of a metapopulation across spatially and temporally variable environments. Our multidimensional research provides a foundation for further long-term genetic monitoring to inform conservation strategies and highlights that sampling scales, ecological effects and cryptic diversity are important considerations to develop realistic understanding of the evolutionary resilience of corals.

MODERN MOLECULAR-GENETIC APPROACH TO INCREASE EFFICIENCY OF SELECTION PROCESS IN ANIMAL BREEDING OF UKRAINE

MODERN MOLECULAR-GENETIC APPROACH TO INCREASE EFFICIENCY OF SELECTION PROCESS IN ANIMAL BREEDING OF UKRAINE

Genetic diversity of reintroduced American martens in Michigan’s Lower Peninsula

Reintroductions are an important conservation and management technique used to restore extirpated populations. Negative genetic consequences (e.g., diversity loss, bottlenecks, inbreeding) are often an unintentional result of reintroductions, due to a small number of founders or suboptimal habitat at release sites. American martens (Martes americana) were extirpated from Michigan's Lower Peninsula in 1911 due to habitat loss and unregulated trapping. Martens were reintroduced into 2 areas of the Lower Peninsula in 1985–1986. The Lower Peninsula reintroduction was characterized by a relatively small number of founders (85 individuals) released into 2 geographically disparate, fragmented sites. We genotyped martens sampled at the 2 release sites approximately 20–25 years since reintroduction, using 11 microsatellite loci. We detected low average allelic richness (3.92 alleles per locus), moderate levels of inbreeding (mean FIS = 0.106), and multiple loci with significant heterozygote deficiencies. Effective population size estimates were small, ranging between 6 and 27 individuals depending on the estimator and the sample group. We also detected significant population structuring between the release sites (FST = 0.093 using the most recent sample). With small population size and limited to no gene flow, we predict the 2 Lower Peninsula marten populations will continue to diverge and potentially further lose genetic diversity. This study highlights the importance of long-term genetic monitoring of reintroduced populations.

Long-term genetic monitoring of a riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae]: Direct anthropogenic impact versus climate change effects.

Modern conservationists call for long term genetic monitoring datasets to evaluate and understand the impact of human activities on natural ecosystems and species on a global but also local scale. However, long-term monitoring datasets are still rare but in high demand to correctly identify, evaluate and respond to environmental changes. In the presented study, a population of the riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae), was monitored over a time period from 1989 to 2013. Study site was an artificial irrigation ditch in one of the last European stone steppes and “nature heritage”, the Crau in Southern France. This artificial riverine habitat has an unusual high diversity of odonate species, prominent indicators for evaluating freshwater habitats. A clearing of the canal and destruction of the bank vegetation in 1996 was assumed to have great negative impact on the odonate larval and adult populations. Two mitochondrial markers (CO1 & ND1) and a panel of nuclear microsatellite loci were used to assess the genetic diversity. Over time they revealed a dramatic decline in diversity parameters between the years 2004 and 2007, however not between 1996 and 1997. From 2007 onwards the population shows a stabilizing trend but has not reached the amount of genetic variation found at the beginning of this survey. This decline cannot be referred to the clearing of the canal or any other direct anthropogenic impact. Instead, it is most likely that the populations’ decay was due to by extreme weather conditions during the specific years. A severe drought was recorded for the summer months of these years, leading to reduced water levels in the canal causing also other water parameters to change, and therefore impacting temperature sensitive riverine habitat specialists like the O. coerulescens in a significant way. The data provide important insights into population genetic dynamics and metrics not always congruent with traditional monitoring data (e.g. abundance); a fact that should be regarded with caution when management plans for developed landscapes are designed.

Erratum to: Development of polymorphic microsatellite markers for the microendemic pupfishes Cyprinodon julimes and C. pachycephalus

We developed microsatellite loci for the Julimes pupfish, Cyprinodon julimes. Twenty-five loci were screened across 19 individuals from Julimes Spring, Chihuahua, Mexico. The number of alleles per locus ranged from 2 to 14, observed heterozygosity ranged from 0.105 to 0.947, and the probability of identity values ranged from 0.022 to 0.588. We then tested for cross-amplification in the bighead pupfish, C. pachycephalus; twenty-three individuals from San Diego de Alcala, Chihuahua, Mexico, were screened across the 20 loci that amplified cleanly. These new loci will be used for long-term genetic monitoring of these critically endangered species.