Management Of Wild Populations Research Articles

Instantaneous vs. non-instantaneous diver-operated stereo-video (DOV) surveys of highly mobile sharks in the Galápagos Marine Reserve

Effective management of wild populations of animals relies on having accurate methods for estimating their densities from field surveys. Surveying sharks and other highly mobile marine predators is particularly difficult, requiring specialised methods that can entail a range of potential biases. Recent simulation studies have suggested that non-instantaneous visual and video survey methods may overestimate densities of highly mobile fishes. A non-instantaneous method is one where each point in space is surveyed for a non-negligible period of time, rather than in an instantaneous ‘snapshot’, allowing animals to move into the survey space during the survey period. We conducted instantaneous and non-instantaneous surveys of sharks (Sphyrna lewini and Carcharhinus galapagensis) around Darwin and Wolf Islands (Galápagos Islands, Ecuador) using diver-operated stereo-video (stereo-DOV) systems with towed GPS. We provide the first empirical evidence of non-instantaneous bias and show that the degree of bias is negatively related to diver swimming speed. At a speed of 40 m min-1, the non-instantaneous method recorded twice as many sharks as the instantaneous method. The bias may be as high as 10 fold at slow speeds (23 m min-1) and negligible at very fast speeds (65 m min-1). Moreover, we used GPS data to produce fine-scale distribution maps, revealing high densities in areas of strong currents along the south-eastern sides of both islands. We recommend the use of stereo-DOV systems with GPS and fast swimming speeds for surveying highly mobile sharks, to produce more realistic estimates of densities on which to base management of these species.

Lipidomics analysis of juveniles' blue mussels (Mytilus edulis L. 1758), a key economic and ecological species.

Blue mussels (Mytilus edulis L. 1758) are important components of coastal ecosystems and in the economy of rural and coastal areas. The understanding of their physiological processes at key life stages is important both within food production systems and in the management of wild populations. Lipids are crucial molecules for bivalve growth, but their diversity and roles have not been fully characterised. In this study, traditional lipid profiling techniques, such as fatty acid (FA) and lipid class analysis, are combined to untargeted lipidomics to elucidate the lipid metabolism in newly settled spat fed on a range of diets. The evaluated diets included single strains treatments (Cylindrotheca fusiformis CCAP 1017/2 -CYL, Isochrysis galbana CCAP 927/1- ISO, Monodopsis subterranean CCAP 848/1 -MONO, Nannochloropsis oceanica CCAP 849/10- NANNO) and a commercial algae paste (SP). Spat growth was influenced by the diets, which, according to their efficacy were ranked as follows: ISO>NANNO/CYL>SP>MONO. A higher triacylglycerols (TG) content, ranging from 4.23±0.82 μg mgashfree Dry weight (DW)-1 at the beginning of the trial (T0) to 51±15.3 μg mgashfreeDW-1 in ISO, characterised significant growth in the spat, whereas, a reduction of TG (0.3±0.08 μg mgashfreeDW-1 in MONO), mono unsaturated FA-MUFA (from 8.52±1.02 μg mgFAashfreeDW-1 at T0 to 2.81±1.02 μg mgFAashfreeDW-1 in MONO) and polyunsaturated FA-PUFA (from 17.57±2.24 μg mgFAashfreeDW-1 at T0 to 6.19±2.49 μg mgFAashfreeDW-1 in MONO) content characterised poor performing groups. Untargeted lipidomics evidenced how the availability of dietary essential PUFA did not influence only neutral lipids but also the membrane lipids, with changes in lipid molecular species in relation to the essential PUFA provided via the diet. Such changes have the potential to affect spat production cycle and their ability to respond to the surrounding environment. This study evidenced the advantages of coupling different lipid analysis techniques, as each technique disclosed relevant information on nutritional requirements of M. edulis juveniles, expanding the existing knowledge on the physiology of this important species.

Genetic Diversity of IGHM and IGHE in the Leporids Revealed Different Patterns of Diversity in the Two European Rabbit Subspecies (O. cuniculus algirus and O. c. cuniculus).

Simple SummaryThe study of European rabbit immunoglobulin genes has contributed decisively to the current knowledge on antibody structure and diversification. The European rabbit has also been increasingly used as an animal model for the study of many human diseases, such as syphilis, tuberculosis, and AIDS. As such, the study of its immune system genes is of crucial relevance, but the study of rabbit immunoglobulins has focused only on the IgG and IgA antibodies. In this study, we added to the knowledge of the rabbit immune system by investigating the genetic diversity of two antibodies, IgM and IgE, in wild and domestic rabbits as well as other rabbit close species. With the data obtained in this study, we showed a high similarity between the different rabbit close species studied and we pointed out important genetic differences in the wild and domestic rabbits. Our findings are a valuable tool for the management of rabbit wild populations and domestic breeds and may contribute to the identification of immunoglobulins genetic variants with greater efficiency against pathogens.The European rabbit (Oryctolagus cuniculus) has been an important model for immunological studies but the study of its immunoglobulins (Ig) has been restricted to its unique IgA and IgG. Here, we studied the genetic diversity of IgM and IgE in several species of leporids and performed population genetics studies on European rabbit wild populations and domestic breeds. The leporids sequencing showed that these Ig are well conserved (98% sequence similarity among leporids), For IgM the Cµ1 and Cµ4 were the most diverse and most conserved domains, respectively, while for IgE the Cε1 was the most diverse domain and Cε2 and Cε3 the most conserved domains. The differences in the pattern of most conserved and most diverse domain between the Ig isotypes are most likely related to each isotype function. The genetic population data showed contrasting results for IgM and IgE. For both Ig, as expected, a greater diversity was observed in the original species range, the Iberian Peninsula. However, unexpectedly the genetic diversity found for IgE in the domestic animals is higher than that for the French wild populations. These results will increase knowledge of the genetic diversity of leporids and wild and domestic rabbit populations and are important tools for the management of wild populations and rabbitries.

Underpinning the Development of Seaweed Biotechnology: Cryopreservation of Brown Algae (Saccharina latissima) Gametophytes.

Sugar kelp (Saccharina latissima) is an economically important species, and natural populations provide diverse and productive habitats as well as important ecosystem services. For seaweed aquaculture to be successful in newly emerging industry in Europe and other Western countries, it will have to develop sustainable production management strategies. A key feature in this process is the capacity to conserve genetic diversity for breeding programs aimed at developing seed stock for onward cultivation, as well as in the management of wild populations, as potentially interesting genetic resources are predicted to disappear due to climate change. In this study, the cryopreservation of male and female gametophytes (haploid life stage) of S. latissima by different combinations of two-step cooling methods and cryoprotectants was explored. We report here that cryopreservation constitutes an attractive option for the long-term preservation of S. latissima gametophytes, with viable cells in all treatment combinations. The highest viabilities for both male and female gametophytes were found using controlled-rate cooling methods combined with dimethyl sulfoxide 10% (v/v). Morphological normal sporophytes were observed to develop from cryopreserved vegetative gametophytic cells, independent of treatment. This indicates that cryopreservation is a useful preservation method for male and female S. latissima gametophytes.

Both candidate gene and neutral genetic diversity correlate with parasite resistance in female Mediterranean mouflon

BackgroundParasite infections can have substantial impacts on population dynamics and are accordingly a key challenge for wild population management. Here we studied genetic mechanisms driving parasite resistance in a large herbivore through a comprehensive approach combining measurements of neutral (16 microsatellites) and adaptive (MHC DRB1 exon 2) genetic diversity and two types of gastrointestinal parasites (nematodes and coccidia).ResultsWhile accounting for other extrinsic and intrinsic predictors known to impact parasite load, we show that both neutral genetic diversity and DRB1 are associated with resistance to gastrointestinal nematodes. Intermediate levels of multi-locus heterozygosity maximized nematodes resistance, suggesting that both in- and outbreeding depression might occur in the population. DRB1 heterozygosity and specific alleles effects were detected, suggesting the occurrence of heterozygote advantage, rare-allele effects and/or fluctuating selection. On the contrary, no association was detected between genetic diversity and resistance to coccidia, indicating that different parasite classes are impacted by different genetic drivers.ConclusionsThis study provides important insights for large herbivores and wild sheep pathogen management, and in particular suggests that factors likely to impact genetic diversity and allelic frequencies, including global changes, are also expected to impact parasite resistance.

Breeding biology of Crimson Finches (Neochmia phaeton) in the eastern Kimberley, Western Australia

ABSTRACTMany species show pronounced differences in life-history traits, from the individual level to divergences between distinct populations. Understanding the variation in these traits provides not only an insight into individual fitness but also essential information for the management of wild populations. Despite their popularity in aviculture and importance for captive research, our knowledge of many Estrildid finches in the wild is limited. Here we detail the breeding behaviour of 12 discrete colonies of Crimson Finch (Neochmia phaeton) in the east Kimberley region of Western Australia over two breeding seasons, and contrast our findings with studies on populations occupying different habitats. We found that many aspects of Crimson Finch breeding biology were consistent across site and studies. However, in our populations, adult survival was lower and group sizes were larger than has been reported elsewhere. We also examined age and sex differences in nestling care and found weak support for age or sex differences in feeding rates. We briefly discuss these findings in relation to theories of colony formation. These findings may help explain the evolution of colonial breeding in this species, as well as having implications for long-term ecosystem management.

Putatively adaptive genetic variation in the giant California sea cucumber (Parastichopus californicus) as revealed by environmental association analysis of restriction-site associated DNA sequencing data.

Understanding the spatial scale of local adaptation and the factors associated with adaptive diversity are important objectives for ecology and evolutionary biology, and have significant implications for effective conservation and management of wild populations and natural resources. In this study, we used an environmental association analysis to identify important bioclimatic variables correlated with putatively adaptive genetic variation in a benthic marine invertebrate-the giant California sea cucumber (Parastichopus californicus)-spanning coastal British Columbia and southeastern Alaska. We used a redundancy analysis (RDA) with 3,699 single nucleotide polymorphisms (SNPs) obtained using RAD sequencing to detect candidate markers associated with 11 bioclimatic variables, including sea bottom and surface conditions, across two spatial scales (entire study area and within subregions). At the broadest scale, RDA revealed 59 candidate SNPs, 86% of which were associated with mean bottom temperature. Similar patterns were identified when population structure was accounted for. Additive polygenic scores, which provide a measure of the cumulative signal across all candidate SNPs, were strongly correlated with mean bottom temperature, consistent with spatially varying selection across a thermal gradient. At a finer scale, 23 candidate SNPs were detected, primarily associated with surface salinity (26%) and bottom current velocity (17%). Our findings suggest that environmental variables may play a role as drivers of spatially varying selection for P.californicus. These results provide context for future studies to evaluate the genetic basis of local adaptation in P.californicus and help inform the relevant scales and environmental variables for in situ field studies of putative adaptive variation in marine invertebrates.

Influence of a growth hormone transgene on the genetic architecture of growth-related traits: A comparative analysis between transgenic and wild-type coho salmon.

Genetic engineering has been increasingly applied to many commercially important plant and animal species, generating phenotypic changes that are not observed in natural populations and creating genetic interactions that have not experienced natural selection. The degree to and way in which such human‐induced genetic variation interacts with the rest of the genome is currently largely unknown. Integrating such information into ecological and risk assessment frameworks is crucial to understand the potential effects of genetically modified organisms in natural environments. Here, we performed QTL mapping to investigate the genetic architecture of growth‐related traits in nontransgenic (NT) and growth hormone transgenic (T) coho salmon with large changes in growth and related physiology, with the aim of identifying how an inserted transgene might influence the opportunity for selection. These fish shared the same parental genetic background, thus allowing us to determine whether the same or different loci influence these traits within the two groups. The use of over 1,700 loci, derived from restriction site‐associated DNA sequencing, revealed that different genomic regions were linked with growth over time between the two groups. Additionally, the effect sizes of detected QTL appear to have been influenced by the transgene. Direct comparison of QTL between the T and NT fish during two size‐matched periods identified little overlap in their location. Taken together, the results showed that the transgene altered the genetic basis of growth‐related traits in this species. The study has important implications for effective conservation and management of wild populations experiencing introduction of transgenes. Evolutionary changes and their ecological consequences may occur at different rates and in different directions in NT versus T individuals in response to selection. Thus, assessments of phenotypic change, and hence ecological risk, should be determined periodically to evaluate whether initial estimates made with founder strains remain valid.

Metabolic effects on carbon isotope biomarkers in fish

Carbon stable isotopes (δ13C) in animal tissues are a powerful tool for tracking biological and environmental change. However, carbon isotope signatures can be altered by both physiological and environmental factors which can cloud interpretation in their use as biomarkers. We investigated metabolic effects (by varying temperatures) on δ13C of three fish tissues (otolith, muscle and liver) and the proportional contributions of environmental water (dissolved inorganic carbon; DIC) and diet (metabolic sources). Juvenile Australasian snapper (Chrysophrys auratus) were laboratory-reared at four temperatures for up to two months and then δ13C in otolith, liver and muscle were measured using isotope-ratio mass spectrometry (IRMS). Temperature significantly altered δ13C signatures in all tissues. δ13C in otoliths reflected carbon signatures from diet and water DIC, with values and variation of proportional contributions influenced by temperature. In muscle and liver, we found differences in δ13C between tissues and across temperature treatments with concurrent high diet-to-tissue fractionation. We conclude that metabolic effects influenced carbon incorporation for all tissues, with otolith carbon providing valuable insights into field metabolic rates. However, metabolic effects complicated the use of soft-tissue to track diet. This study deepens our understanding of internal and external drivers of carbon isotopic signatures in fish tissues and enhances their utility as a biomarker in the field. Improved insight into biomarkers facilitates more accurate predictions of ecological and environmental change for better understanding and management of wild populations.

Thermal tolerance traits of the undulated surf clam Paphia undulata based on heart rate and physiological energetics

Thermal tolerance traits are important factors that affect the ability of an aquaculture species to survive, grow, and reproduce in new habitats. Paphia undulata, a species of saltwater clam, has been farmed in China for over thirty years. Despite this, the ecophysiology of P. undulata and its effects on the aquaculture of this species are poorly understood. To investigate the thermal tolerance of P. undulata, the semi-lethal temperature, cardiac activity, and scope for growth (SFG) of the organisms were measured under different thermal stresses in a laboratory-simulated muddy habitat condition. Our results showed that the cardiac activity, feeding behaviors, and respiration rates of P. undulata were positively correlated with temperature changes from 10 °C to 32 °C. The upper incipient lethal temperature (192-h UILT50) and Arrhenius break temperature (ABT) of this species were 33.49 ± 0.02 °C and 35.64 ± 0.77 °C, respectively. SFG trend had negative values at temperatures between 10 °C and 16 °C and positive values at temperatures between 18 °C to 32 °C. These data suggest that the suitable thermal window that provided the energy required for the efficient growth and reproduction of P. undulata in the Dongshan Bay was approximately nine months out of the year. Taken together, these results indicate that P. undulata is proficient at adapting to thermal stress in the subtidal zone. Moreover, our results may also provide information that assists in both the management of wild populations of P. undulata and the improvement of P. undulata aquaculture.

Evaluating sample size to estimate genetic management metrics in the genomics era.

Inbreeding and relationship metrics among and within populations are useful measures for genetic management of wild populations, but accuracy and precision of estimates can be influenced by the number of individual genotypes analysed. Biologists are confronted with varied advice regarding the sample size necessary for reliable estimates when using genomic tools. We developed a simulation framework to identify the optimal sample size for three widely used metrics to enable quantification of expected variance and relative bias of estimates and a comparison of results among populations. We applied this approach to analyse empirical genomic data for 30 individuals from each of four different free-ranging Rocky Mountain bighorn sheep (Ovis canadensis canadensis) populations in Montana and Wyoming, USA, through cross-species application of an Ovine array and analysis of approximately 14,000 single nucleotide polymorphisms (SNPs) after filtering. We examined intra- and interpopulation relationships using kinship and identity by state metrics, as well as FST between populations. By evaluating our simulation results, we concluded that a sample size of 25 was adequate for assessing these metrics using the Ovine array to genotype Rocky Mountain bighorn sheep herds. However, we conclude that a universal sample size rule may not be able to sufficiently address the complexities that impact genomic kinship and inbreeding estimates. Thus, we recommend that a pilot study and sample size simulation using R code we developed that includes empirical genotypes from a subset of populations of interest would be an effectiveapproach to ensure rigour in estimating genomic kinship and population differentiation.

Pedigree‐based genetic management improves bison conservation

ABSTRACTOverhunting and widespread land use change nearly caused the extinction of North American bison (Bison bison) by the late 1800s. Recovery efforts focused on preserving the remaining individuals and establishing federally managed conservation herds to build more sustainable populations. Today, bison in conservation herds are maintained in small, isolated herds that are managed through an annual or biannual cull of individuals to maintain target population sizes. We assessed alternative culling strategies for maintaining genetic variation over the long term in managed wild bison herds. Our objective was to compare a strategy modeled after a United States Fish and Wildlife Service strategy (all‐allele conservation culling strategy [AAC]) to a pedigree‐based mean kinship strategy (MK) and to a Random strategy that does not incorporate genetic data and is used to manage some conservation herds. We built an individual‐based model, parameterized in accordance with bison biology, to compare these culling strategies in 2 federally managed conservation herds at the Fort Niobrara National Wildlife Refuge (FTN herd) and the National Bison Range (NBR herd). Our MK strategy retained more genetic variation and slowed the accumulation of inbreeding relative to the AAC or Random strategies, and these findings were consistent across wild bison herds with different founding sizes and current genetic diversity. These findings extend previous work demonstrating the utility of pedigree‐based management strategies in captive and wild population management, and show that such strategies maximize the retention of genome‐wide variation in contemporary bison herds. The modeling approach used in this study was useful for assessing outcomes prior to implementation, and the specific models developed for this study can be easily adapted to other managed wildlife species. © 2018 The Wildlife Society.

\u2018Intentional Genetic Manipulation\u2019 as a conservation threat

Wildlife ranching including the hunting, collection, sales and husbandry of wild animals in captivity, is practised worldwide and is advocated as an approach towards the conservation of wild species. While many authors have explored the biological impacts of intensive wild population management, primarily with respect to disease transmission (especially in ungulates and fish), the evolutionary and demographic effects of wildlife ranching have been examined less intensively. We discuss this issue through the case of intensive wildlife management in southern Africa. The genetic consequences of this global practice, with an emphasis on Africa, were addressed by a motion passed at the 2016 IUCN World Congress- ‘Management and regulation of intensive breeding and genetic manipulation of large mammals for commercial purposes’. Here, we highlight concerns regarding intensive breeding programs used to discover, enhance and propagate unusual physical traits, hereafter referred to as ‘Intentional Genetic Manipulation’. We highlight how ‘Intentional Genetic Manipulation’ potentially threatens the viability of native species and ecosystems, via genetic erosion, inbreeding, hybridisation and unregulated translocation. Finally, we discuss the need for better policies in southern Africa and globally, regarding ‘Intentional Genetic Manipulation’, and the identification of key knowledge gaps.

Conservation genetics of otters: Review about the use of non-invasive samples

Wild population management programs require determining some fundamental aspects for conservation, including population structure, flow between populations, evolutionary history and kinship, among others. Since sample collection from wild mammals for DNA extraction is a complex task, conservation genetics has developed non-invasive sampling techniques, which allow obtaining DNA without the need to capture individuals. For the genetic characterization of otter populations, stools are frequently used as source of DNA for amplification of molecular markers (microsatellites, mitochondrial segments and sequences for determining sex) in studies on genetic diversity, phylogeography, population structure and size, among others. This review summarizes the application of non-invasive sampling techniques in genetic studies of otter species. Genetic characterization studies that use stools as source of DNA support the usefulness of this material to get amplified markers in the genotyping of individuals. They also suggest the use of fresh samples and appropriate conservation methods to avoid DNA degradation, as well as quantify the potential errors in genotyping, such as false and null alleles.

Clonal structure through space and time: High stability in the holothurian Stichopus chloronotus (Echinodermata).

Sea cucumbers are increasingly exploited for human consumption and for their curative properties, and many wild populations are now depleted or in danger of extinction. While aquaculture is seen as an alternative to fisheries and as a mean to restore wild populations, more knowledge is needed on their reproductive strategies to render this practice efficient, notably for fissiparous holothurians, which are some of the mobile animals able of asexual reproduction by transverse fission. Little information is available on their population genetic diversity and structure. Here, the clonal structure of populations of the fissiparous sea cucumber Stichopus chloronotus has been investigated using nine microsatellite loci and a random sampling, at different spatial (intra‐reef and inter‐reef) and temporal (inter‐season and inter‐year) scales. Our findings highlight the importance of asexual reproduction in maintaining these populations, and the prevalence of the “initial seedling recruitment” strategy (ISR), leading to a high stability of clonal composition over seasons and years. It also seemed that clonal propagation was limited to the reef scale (<10 km) while reefs were connected by sexual dispersal. This is the first time that clonal structure in sea cucumbers has been studied at such a fine scale, with a specific sampling strategy. It provides key findings on the genetic diversity and structure of fissiparous sea cucumbers, which will be useful for the management of wild populations and aquaculture.

Individual heterogeneity and effects of harvest on greater sage‐grouse populations

ABSTRACTThe influence of harvest on wild populations has been the focus of substantial debate, and has widespread implications for the management of wild populations. Traditional views of harvest are based on density‐dependent responses of populations to harvest. However, alternate mechanisms can and do induce compensation (e.g., individual heterogeneity). Selective harvest of successful females and their offspring is thought to occur in some grouse populations (e.g., blue grouse [Dendragapus spp.], greater sage‐grouse [Centrocercus urophasianus]), and delaying harvest within a season has been proposed as a viable strategy to overcome this type of selective harvest. However, a recent examination regarding the effects of harvest on greater sage‐grouse strongly criticized the recommendation of delayed harvest. Herein, we address the criticism of the delayed harvest strategy and provide an examination of projecting the effects of harvest in the face of individual heterogeneity using deterministic projection models. We demonstrate that under proportional harvesting strategies, given a fixed harvest rate, early additive harvest does not have a larger effect on the population than additive harvest later in the season. Moreover, we show that when higher quality individuals (i.e., individuals with higher survival and reproductive rates) are more susceptible to harvest, individual heterogeneity in harvest effects will induce depensatory dynamics when density‐dependent effects are only additive. Conversely, even when density‐dependent effects are additive, if lower quality individuals are more susceptible to harvest, heterogeneity will induce partial compensation. Reducing the selectivity of harvest on higher quality individuals (i.e., shifting harvest onto lower quality groups) could reduce the risk of artificial selection and induce partial compensation. Therefore, we recommend managers consider the spatiotemporal patterns of populations and time harvest to maximize the heterogeneity tradeoff between higher and lower quality individuals. © 2017 The Wildlife Society.

Sex-specific differences in transcriptome profiles of brain and muscle tissue of the tropical gar

BackgroundThe tropical gar (Atractosteus tropicus) is the southernmost species of the seven extant species of gar fishes in the world. In Mexico and Central America, the species is an important food source due to its nutritional quality and low price. Despite its regional importance and increasing concerns about overexploitation and habitat degradation, basic genetic information on the tropical gar is lacking. Determining genetic information on the tropical gar is important for the sustainable management of wild populations, implementation of best practices in aquaculture settings, evolutionary studies of ancient lineages, and an understanding of sex-specific gene expression. In this study, the transcriptome of the tropical gar was sequenced and assembled de novo using tissues from three males and three females using Illumina sequencing technology. Sex-specific and highly differentially expressed transcripts in brain and muscle tissues between adult males and females were subsequently identified.ResultsThe transcriptome was assembled de novo resulting in 80,611 transcripts with a contig N50 of 3,355 base pairs and over 168 kilobases in total length. Male muscle, brain, and gonad as well as female muscle and brain were included in the assembly. The assembled transcriptome was annotated to identify the putative function of expressed transcripts using Trinotate and SwissProt, a database of well-annotated proteins. The brain and muscle datasets were then aligned to the assembled transcriptome to identify transcripts that were differentially expressed between males and females. The contrast between male and female brain identified 109 transcripts from 106 genes that were significantly differentially expressed. In the muscle comparison, 82 transcripts from 80 genes were identified with evidence for significant differential expression. Almost all genes identified as differentially expressed were sex-specific. The differentially expressed transcripts were enriched for genes involved in cellular functioning, signaling, immune response, and tissue-specific functions.ConclusionsThis study identified differentially expressed transcripts between male and female gar in muscle and brain tissue. The majority of differentially expressed transcripts had sex-specific expression. Expanding on these findings to other developmental stages, populations, and species may lead to the identification of genetic factors contributing to the skewed sex ratio seen in the tropical gar and of sex-specific differences in expression in other species. Finally, the transcriptome assembly will open future research avenues on tropical gar development, cell function, environmental resistance, and evolution in the context of other early vertebrates.

Larval Dispersal of Abalone and Its Three Modes: a Review

Abalone are planktonic larvae in their early life history stages, and their dispersal predominantly takes place during these stages. Abalone stocks rely on the natural supply of larvae in self-recruiting populations, larval connectivity in metapopulations, and artificial hatchery—produced larvae in regions where larval restoration is needed. Larval dispersal is, therefore, one of the key factors in the management of wild populations as well as in the establishment of resilient and genetically viable populations during restoration. In this review of abalone larval dispersal studies conducted in different regions of the world, evidence is found for three modes of larval dispersal; (1) short distance, (2) long distance, and (3) both short and long distance (dual mode). Four biological factors (spawning, larval duration, vertical behaviors, and presettlement mortality) are proposed to influence larval dispersal. Consideration of larval dispersal mode, influential biological factors, and their interactions may improve estimation of connectivity in metapopulations for establishment of effective marine protected areas, which could help the recovery of declining populations and the conservation of endangered abalone species.

Social preferences for adaptation measures to conserve Australian birds threatened by climate change

AbstractDebate about climate change adaptation for biodiversity, and the ethics and consequences of assisted colonization in particular, has polarized professional opinion but the views of the wider community are unknown. We tested four hypotheses about the acceptability of adaptation strategies among a sample of the Australian general public using a combination of direct questions and a choice experiment. We found that (1) among the 80% who wanted extinction avoided, increased in situ management of wild populations was preferred to captive breeding or assisted colonization, (2) preferences for adaptation strategies were not explained by gender, income, education or knowledge about birds, (3) genetically distinctive taxa were not actively preferred, (4) &gt; 60% of respondents were content for conservation managers to make decisions about strategies rather than local communities or the general public. The results provide Australian policy makers with a mandate to bolster efforts to retain existing populations but suggest that assisted colonization and captive breeding could be accepted if essential.

Making sense of the relationships between Ne, Nb and Nc towards defining conservation thresholds in Atlantic salmon (Salmo salar).

Effective population size over a generation (Ne) or over a reproductive cycle (Nb) and the adult census size (Nc) are important parameters in both conservation and evolutionary biology. Ne provides information regarding the rate of loss of genetic diversity and can be tracked back in time to infer demographic history of populations, whereas Nb may often be more easily quantified than Nc for short-term abundance monitoring. In this study, we propose (1) an empirical context to Waples et al. (2014) who introduced a correction to bias due to overlapping generations, and (2) a mathematical relationship between Ne and Nb for direct application in Atlantic salmon populations in Québec, Canada. To achieve this, we investigate the relationships between Ne, Nb and Nc in 10 Atlantic salmon populations, Canada, for which we genotyped 100 randomly sampled young-of-the year individuals for 5 consecutive years. The results show a positive correlation between Ne, Nb and Nc, suggesting that Nb is an indicative parameter for tracking effective population size and abundance of Atlantic salmon. However, our model allows predicting Nc from Nb values at 27% that can be partly explained by high variance in Nb/Nc both among populations (37%) and among years (19%). This result illustrates the need for thorough calibration of Nb/Nc before using Nb in monitoring programs, as well as a full understanding of the limits of such an approach. Finally, we discuss the importance of these results for the management of wild populations.