Populations Of Invasive Species Research Articles

Intraspecific variation in the functional response of an invasive crayfish under different temperatures

Non-native species can react to changes to their thermal environment by altering their feeding behaviour, thereby potentially causing shifts in predator-prey dynamics and competitive dominance over native species. In this study, we measured intraspecific variation in the functional response (i.e., predation rate as a function of prey density) of the rusty crayfish Faxonius rusticus (Girard, 1852) at two temperatures (18˚C and 26˚C) in the laboratory. We compared six invasive populations spanning a 2˚ latitudinal gradient in eastern North America, to test the prediction that under warmer conditions individuals from more southerly populations exhibit a higher functional response than those from northern populations. Temperature, latitude, and the interaction between these two variables had significant effects on attack rates and handling times of individual crayfish from the tested populations. Contrary to our prediction, the attack rates of individuals from northern populations were consistently higher than those from southern populations at both temperatures. We propose that these interpopulation differences in functional response could arise, at least in part, from countergradient selection. Our results suggest that climate warming promotes spatiotemporal variation in per capita effects across latitudinally distributed populations of aquatic invasive species.

Prevalence of the crayfish plague pathogen in red swamp crayfish populations in western France: How serious is the risk for the native white-clawed crayfish?

The crayfish plague pathogen Aphanomyces astaci has been implicated in a number of mass mortalities and irreversible population declines of native crayfish across Europe. At present, the reservoirs of the pathogen in Europe are mainly populations of invasive North American crayfish species. In southwestern Europe, including France, a particularly widespread invader is the red swamp crayfish Procambarus clarkii. Recent distribution data confirm that P. clarkii is present in at least 75 French departments, i.e. more than 78% of those in metropolitan France. We analysed the prevalence and pathogen load of A. astaci in 42 populations of this species in western France (Nouvelle Aquitaine region), where the species is most densely distributed, particularly in a wide range of environments around the Gironde estuary. The pathogen was detected by two different quantitative PCR assays in more than three quarters of the populations studied (34 out of 42); 163 out of 480 analysed crayfish individuals tested positive for the presence of A. astaci. In most cases, individual infection levels were very low, detectable with quantitative PCR but not sufficient for pathogen genotyping. In seven P. clarkii individuals from four populations, however, we were able to assess A. astaci variation by microsatellite markers and sequencing of mitochondrial markers. All these host specimens carried A. astaci genotype group D, haplotype d1, which has caused the majority of crayfish plague outbreaks in neighbouring Spain. In contrast, the French outbreaks genotyped to date (including eight newly analysed in this study) were mostly caused by strains of genotype group B, specific to the signal crayfish Pacifastacus leniusculus. Haplotype d1 found in P. clarkii was involved in one of the newly characterised outbreaks. Our study confirms that P. clarkii is a potentially important reservoir of the crayfish plague pathogen in France, but not the main source of the pathogen in mass mortalities of A. pallipes, probably due to different ecological requirements of the different invasive host crayfish. However, as P. clarkii continues to spread, the threat posed by this species to native crayfish is likely to increase.

Large-landscape connectivity models for pond-dwelling species: methods and application to two invasive amphibians of global concern

ContextFunctional connectivity models are essential in identifying major dispersal pathways and developing effective management strategies for expanding populations of invasive alien species. However, the extrapolation of models parameterized within current invasive ranges may not be applicable even to neighbouring areas, if the models are not based on the expected responses of individuals to landscape structure.ObjectivesWe have developed a high-resolution connectivity model for both terrestrial and aquatic habitats using solely potential sources. The model is used here for the invasive, principally-aquatic, African clawed frog Xenopus laevis, which is a species of global concern.MethodsAll ponds were considered as suitable habitats for the African clawed frog. Resistance costs of lotic aquatic and terrestrial landscape features were determined through a combination of remote sensing and laboratory trials. Maximum cumulative resistance values were obtained via capture-mark-recapture surveys, and validation was performed using independently collected presence data. We applied this approach to an invasive population of the American bullfrog, Lithobates catesbeianus, in France to assess its transferability to other pond-dwelling species.ResultsThe model revealed areas of high and low functional connectivity. It primarily identified river networks as major dispersal pathways and pinpointed areas where local connectivity could be disrupted for management purposes.ConclusionOur model predicts how the dispersal of individuals connect suitable lentic habitats, through river networks and different land use types. The approach can be applied to species of conservation concern or interest in pond ecosystems and other wetlands, including aquatic insects, birds and mammals, for which distribution data are limited or challenging to collect. It serves as a valuable tool for forecasting colonization pathways in expanding populations of both native and invasive alien species and for identifying regions suitable for preventive or adaptive control measures.

Recommendations for the use of conservation detection dogs in seabird research: a thematic analysis

Conservation detection dog handler teams (CDDHTs) offer many potential benefits to the world of conservation. Seabird populations are an important component of marine ecosystems. However, they are threatened by several anthropogenic activities, including the introduction of invasive species. Although CDDHT can support seabird conservation through invasive species management efforts and population assessments, they are under-utilised. A lack of methodological standardisation within CDDHT work and the under-publishing of their use within seabird research leads to difficulties in conducting new CDDHT seabird-related studies due to an inability to learn from previous research. This study aimed to address these shortcomings by investigating the techniques and methods used by those actively working with, or planning to work with, CDDHT on a seabird project to better understand them, and propose best practices in the field. Seven professionals who have used, or will use, CDDHT as part of a seabird project (four handlers, three ecologists/researchers) participated in structured written surveys which were thematically analysed. Five superordinate themes emerged from the survey data: Training, Location, Role of Handler, Wildlife Considerations, and Dog Selection Criteria, with the first two themes having several subordinate themes. A summary of best practices was developed from the findings, with notable recommendations including preparation across all project elements, networking with other professionals, and making judgments on the use of techniques like discrimination and field trials based on the specific project and dog(s). These results can serve to benefit future seabird studies involving CDDHT as well as supporting the development of standardisation in the CDDHT field.

Molecular detection of DNA from Trypanosoma spp. and Leishmania spp. in wild boar (Sus scrofa) tissues

Due to the proximity of humans to the countryside and the progressive increase in populations of invasive species, such as wild boars (Sus scrofa), the risk of disease spread is also exacerbated, some of which are zoonoses caused by protozoa. In the present study, 75 tissue/organ samples from 25 wild boars obtained from authorized hunting in the northern region of Rio Grande do Sul were evaluated to investigate the presence of Trypanosoma spp. using conventional PCR with specific primers and amplification of the ITS1 region for Leishmania spp. detection and species differentiation, multiplex PCR with kDNA minicircle amplification was performed. Trypanosoma spp. DNA was detected in 11 out of 25 hearts, representing 44% of the culled animals. Regarding the detection of Leishmania DNA, L. infantum was detected in one spleen sample, accounting for 4%, and L. amazonensis in one liver sample from the same animal, also representing 4% (1/25) of the samples. It is important to note that this wild boar, with detection for both L. amazonensis and L. infantum, also had Trypanosoma spp. DNA detected in a heart sample, indicating the potential of this species to have multiple infections with these agents. Furthermore, this is the first reported case of multiple infection in a wild boar with these agents. Therefore, the results obtained reinforce the risk posed by invasive species, especially wild boars, as potential sources of infectious agent dissemination and their role as possible reservoirs for numerous diseases.

Investigating the impacts of agricultural land use on soil earthworm communities: A case study of northern Zagros Mountains of Iran

Earthworms play a crucial role in the invertebrate community of soil by contributing to the belowground biomass and biogeochemical cycle. Environmental stresses, such as human activities and land use changes, have been found to negatively affect their abundance and diversity. To investigate the impact of agricultural land use and pastures on earthworms' genetic diversity in the Northern Zagros Mountains, we used COI molecular marker and DNA barcoding approaches. We collected earthworm specimens from four farmland sites and six pastures and assessed the abundance and species composition of earthworm communities across the two land uses using quadrat sampling. Using the barcoding method, we identified 13 molecular operational taxonomic units (MOTUs) among the captured earthworms. Our results showed that the number of total MOTUs, density, and earthworm communities differed significantly between the two land uses. We also found that pastures had more abundant earthworms, while farmlands had greater diversity. The diversity of OTUs in the Lumbricidae family was dominant in the agricultural system. Overall, the population of invasive earthworm species in cultivation systems is influenced by chemical inputs and organic materials from plant residues, cover crops, manure, or organic fertilizers. Given the rapid rate of land use change worldwide, especially in Iran, it is crucial to understand the impact of disturbances on earthworms.

Parasitic helminths of alien invasive anurans in Butuan City, Northeastern Mindanao, Philippines.

This study aimed to identify the helminth parasites of invasive anuran species in selected barangays in Butuan City, Philippines. In urbanized areas, invasive species dominate anuran diversity, and one of the primary threats they pose to native wildlife is the transmission of diseases and parasites. Out of the 91 collected individuals of invasive anuran species, Rhinella marina was the most abundant (88 %), followed by Hoplobatrachus rugulosus (12 %) and Kaloula pulchra (3 %). The study identified five species of parasites, with Spirometra sp. being the most prevalent (17.58 %), followed by Echinostoma sp. (16.5 %), Rhabdias bufonis (14.3 %), Cosmocerca sp. (6.6 %), and Strongyloides stercoralis (3.30 %), respectively. Spirometra sp. also had the highest intensity (7.67), followed by Cosmocerca sp. (5), Strongyloides stercoralis (3.33), Rhabdias bufonis (3.30), and Echinostoma sp. (2.73). This parasitological survey revealed that H. rugulosus had the highest prevalence and infection of parasites, and residential areas had the highest parasite prevalence among the habitat types. Adult hosts were found to harbor a higher prevalence and intensity, and male hosts had a higher prevalence. The results highlight the high risk of parasite transmission from anurans to other animals and emphasize the need for the community to control the population of invasive anuran species for the safety of native anurans and to prevent zoonotic transmission to other animals and humans.

Assessing the suitability of YY males and ZZ females as an invasive species population control method across life histories

Natural resource managers use tools to control invasive species. In theory, stocking YY males or ZZ females would allow managers to skew sex ratios until populations collapse. In combination with other suppression methods, such as removal, this approach could be incorporated into Integrated Pest Management plans. For example, fishery managers have stocked YY males to control isolated non-native brook trout (Salvelinus fontinalis) populations. However, life histories and demographic factors (e.g., lifespans) vary across species and could affect the feasibility of skewing sex ratios as an effective control strategy for a given population. Likewise, some species may have sex determinations that do not allow population control through sex-skewing methods. We compared five representative aquatic invasive species with global invasion ranges for potential control by skewing the sex ratio through closed population simulations: red swamp crayfish (Procambarus clarkii), zebra mussels (Dreissena polymorpha), lake trout (Salvelinus namaycush), silver carp (Hypophthalmichthys molitrix), and Nile tilapia (Oreochromis niloticus). We determined that Nile tilapia, red swamp crayfish, and zebra mussels would be the most suitable to control through skewing the sex ratio assuming appropriate sex determination exists in the species. Lake trout could be eliminated by stocking YY males but would require either long stocking periods or high stocking numbers because of the long lifespan of the species. Silver carp populations were more difficult to crash because they live longer and produce many recruits. Broadly, these patterns demonstrated that short lived species lend themselves to control by skewing the sex ratio.

The faunal Ponto-Caspianization of central and western European waterways

As alien invasive species are a key driver of biodiversity loss, understanding patterns of rapidly changing global species compositions depends upon knowledge of invasive species population dynamics and trends at large scales. Within this context, the Ponto-Caspian region is among the most notable donor regions for aquatic invasive species in Europe. Using macroinvertebrate time series collected over 52 years (1968–2020) at 265 sites across 11 central and western European countries, we examined the occurrences, invasion rates, and abundances of freshwater Ponto-Caspian fauna. We examined whether: (i) successive Ponto-Caspian invasions follow a consistent pattern of composition pioneered by the same species, and (ii) Ponto-Caspian invasion accelerates subsequent invasion rates. In our dataset, Ponto-Caspian macroinvertebrates increased from two species in 1972 to 29 species in 2012. This trend was parallelled by a non-significant increasing trend in the abundances of Ponto-Caspian taxa. Trends in Ponto-Caspian invader richness increased significantly over time. We found a relatively uniform distribution of Ponto-Caspian macroinvertebrates across Europe without any relation to the distance to their native region. The Ponto-Caspian species that arrived first were often bivalves (46.5% of cases), particularly Dreissena polymorpha, followed secondarily by amphipods (83.8%; primarily Chelicorophium curvispinum and Dikerogammarus villosus). The time between consecutive invasions decreased significantly at our coarse regional scale, suggesting that previous alien establishments may facilitate invasions of subsequent taxa. Should alien species continue to translocate from the Ponto-Caspian region, our results suggest a high potential for their future invasion success highly connected central and western European waters. However, each species’ population may decline after an initial ‘boom’ phase or after the arrival of new invasive species, resulting in different alien species dominating over time.

Mycobacterial Infections in Invasive Turtle Species in Poland.

Over the last 30 years, the number of invasive turtle species living in the wild has significantly increased in Poland. This proliferation carries many threats, which mainly include the displacement of native species of animals from their natural habitats. Turtles can also be reservoirs for pathogens, including bacteria from the Mycobacterium genus. In order to confirm or rule out the presence of acid-fast mycobacteria in the population of invasive turtle species, samples from carapace, plastron, internal organs and mouth cavity swabs from 125 animals were tested. Twenty-eight mycobacterial strains were isolated in culture, which were classified as atypical following multiplex-PCR reactions. The GenoType Mycobacterium Common Mycobacteria (CM) test, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, PCR-restriction fragment length polymorphism (PRA)-hsp65 and DNA sequencing were used to identify the species of isolates. Of the 28 strains, 11 were identified as M. fortuitum, 10 as M. chelonae, 3 as M. avium ssp. avium, 2 as M. nonchromogenicum and 1 each of M. neoaurum and M. scrofulaceum. The results of the research will also strengthen the understanding that these animals can be vectors for pathogens when living in the wild.

Drone-Based Identification and Monitoring of Two Invasive Alien Plant Species in Open Sand Grasslands by Six RGB Vegetation Indices

Today, invasive alien species cause serious trouble for biodiversity and ecosystem services, which are essential for human survival. In order to effectively manage invasive species, it is important to know their current distribution and the dynamics of their spread. Unmanned aerial vehicle (UAV) monitoring is one of the best tools for gathering this information from large areas. Vegetation indices for multispectral camera images are often used for this, but RGB colour-based vegetation indices can provide a simpler and less expensive solution. The goal was to examine whether six RGB indices are suitable for identifying invasive plant species in the QGIS environment on UAV images. To examine this, we determined the shoot area and number of common milkweed (Asclepias syriaca) and the inflorescence area and number of blanket flowers (Gaillardia pulchella) as two typical invasive species in open sandy grasslands. According to the results, the cover area of common milkweed was best identified with the TGI and SSI indices. The producers’ accuracy was 76.38% (TGI) and 67.02% (SSI), while the user’s accuracy was 75.42% (TGI) and 75.12% (SSI), respectively. For the cover area of blanket flower, the IF index proved to be the most suitable index. In spite of this, it gave a low producer’s accuracy of 43.74% and user’s accuracy of 51.4%. The used methods were not suitable for the determination of milkweed shoot and the blanket flower inflorescence number, due to significant overestimation. With the methods presented here, the data of large populations of invasive species can be processed in a simple, fast, and cost-effective manner, which can ensure the precise planning of treatments for nature conservation practitioners.

Long-term macrophyte and snail community responses to population declines of invasive rusty crayfish (Faxonius rusticus).

A central focus of invasive species research has been on human efforts to eradicate invaders or reduce their abundance to mitigate the worst of their impacts. In some cases, however, populations of invasive species decline without human intervention, which may inform management responses to these invaders. Such is the case of the invasive rusty crayfish (Faxonius rusticus) in northern Wisconsin, USA, where systematic population monitoring since 1975 has revealed population declines in approximately half of the lakes surveyed. Population declines of invasive species without human intervention remain understudied, but there is even less research on how communities respond following such declines. Using 10 lakes in Vilas County, Wisconsin, we investigated community recovery of habitat (macrophytes) and prey (freshwater snails) of F. rusticus following up to 33 years of declines of this invader in some lakes using a dataset with a rare, long-term span over which consistent data were collected (1987, 2002, 2011, and 2020). We compared community responses in lakes where F. rusticus populations reached a peak and subsequently declined (boom-bust lakes) and lakes where our dataset only captured the decline of F. rusticus (bust lakes) to reference lakes with consistently high or low crayfish abundance over time. We found partial recovery of macrophytes and snails in the bust and boom-bust lakes where F. rusticus has declined, with recovery of macrophyte abundance and richness in the boom-bust lakes achieving levels observed in the low-crayfish reference lakes. Snail abundance and richness increased after declines of F. rusticus, though not to the level of the low-crayfish reference lakes, suggesting that snail recovery may lag macrophyte recovery because snails are dependent on macrophytes and associated periphyton for habitat. The recovery we document potentially represents long-term ecosystem resilience of lakes to biological invasions. Our results suggest that lake communities may recover without active restoration interventions after invasive crayfish population declines, although identifying which lakes experience these natural declines remains a priority for future research and management.

Simulations Reveal High Efficiency and Confinement of a Population Suppression CRISPR Toxin-Antidote Gene Drive.

Though engineered gene drives hold great promise for spreading through and suppressing populations of disease vectors or invasive species, complications such as resistance alleles and spatial population structure can prevent their success. Additionally, most forms of suppression drives, such as homing drives or driving Y chromosomes, will generally spread uncontrollably between populations with even small levels of migration. The previously proposed CRISPR-based toxin-antidote system called toxin-antidote dominant embryo (TADE) suppression drive could potentially address the issues of confinement and resistance. However, it is a relatively weak form of drive compared to homing drives, which might make it particularly vulnerable to spatial population structure. In this study, we investigate TADE suppression drive using individual-based simulations in a continuous spatial landscape. We find that the drive is actually more confined than in simple models without space, even in its most efficient form with low cleavage rate in embryos from maternally deposited Cas9. Furthermore, the drive performed well in continuous space scenarios if the initial release requirements were met, suppressing the population in a timely manner without being severely affected by chasing, a phenomenon in which wild-type individuals avoid the drive by recolonizing empty areas. At higher embryo cut rates, the drive loses its ability to spread, but a single, widespread release can often still induce rapid population collapse. Thus, if TADE suppression gene drives can be successfully constructed, they may play an important role in control of disease vectors and invasive species when stringent confinement to target populations is desired.

Specificity and Sensitivity of a Rapid LAMP Assay for Early Detection of Emerald Ash Borer (Agrilus planipennis) in Europe

Buprestids are an emerging threat to broadleaf forests across the world. Species such as emerald ash borer (EAB, Agrilus planipennis) seriously threaten ash (Fraxinus spp.) in North America and Europe. As it continues spreading west from European Russia, native European ash populations will suffer dramatic losses. Due to their cryptic lifestyle of the egg and larval stages on developing bark and vascular tissue, buprestids and other wood borers can be difficult to detect. Early detection tools are vital to implement fast eradication measures, and prevent the establishment of invasive species populations. Detection methods using polymerase chain reaction (PCR) assays to target specific taxa can be extremely timely to obtain results especially since samples need to be transported to the laboratory first. However, loop-mediated isothermal amplification (LAMP) eDNA assays are highly specific and sensitive providing results within 30 min after sample extraction. In this study, we investigated the specificity and sensitivity of an EAB LAMP assay as an early detection tool in Europe. The assay was specific to EAB when tested against 12 European Agrilus spp., five buprestids, two Scolytinae, and five cerambycids (n = 24). The LAMP assay sensitivity amplified DNA from a concentration as low as 0.02 pg/µL. These results demonstrate that the LAMP assay is a highly specific, sensitive tool that can be used to detect and monitor EAB in European forests and urban settings.

Non-Native Plants Species and Biodiversity of Socotra Island, Yemen

Socotra Island has significant ecological and economic importance at local, national and global scales. Invasive plant species are often considered as potential competitors of native species due to their usual greater capacity for colonization and expansion. The spread of alien plant species has long been recognized as one of the most significant environmental changes due to its ability to decrease biodiversity and alter ecosystem processes. In areas with homogeneity population of wild invasive species especially Argemone mexicana, 32 random sites were randomly detected. Ninety six Quadrates plots were laid down to study the interaction between the invasive plant and the native species especially with conservation attention of endemic plant species. The main aims is to provide base informatics data to establish comprehensive habitat surveillance programs to enable early detection and rapid response of IAS, prevent both intentional or accidental introductions of harmful invasive alien species to the Socotra Island and reduce the likelihood of alien species invasions by decreasing stresses on vulnerable at-risk ecosystems and species. This study was conducted to identify the different types of invasive species present, the rate and pattern of invasion, its intensity, association of invaders and their habitat preference in the Socotra ecosystem. Vegetation sampled in 96 quadrats, each 10 m _ 10 m; through a combination of random and systematic sampling recorded 42 plant species of 36 genera belonging to 24 families with around 10% was recorded as invasive species. Diversity indices like richness, evenness, Simpson and Shannon-Wiener have been analyzed.

Gastropod chemoreception behaviors—Mechanisms underlying the perception and location of targets and implications for shellfish fishery development in aquatic environments

Chemoreception is one of the most important senses and it plays a key role in the survival and adaptation of animals to their environments. Many gastropods, such as Rapana venosa and Neptunea cumingii, have emerged as economically important shellfish. Meanwhile, invasive gastropods have destroyed commercial shellfisheries in many countries. Given the importance of chemoreception in the behavior of aquatic gastropods, the mechanism of their chemical perception has recently garnered attention. To provide a foundation for understanding the chemoreception of aquatic gastropods, we reviewed recent studies and summarized the chemoreception behaviors and mechanisms that gastropods use to perceive and locate targets in aquatic environments, along with relevant molecular and genetic insights. We highlight several of the implications of these studies for chemoreception-related research and shellfish fishery development. This review should aid in the rational development and utilization of gastropod resources as well as in controlling the populations of invasive species.

Drought reduces invasive grass performance by disrupting plant-microbe interactions that enhance plant nitrogen supply.

Non-native invasive plants can promote their dominance in novel ecosystems by accelerating soil nutrient cycling via interactions with decomposer microbes. Changes in abiotic conditions associated with frequent or prolonged drought may disrupt these interactions, but the effects of disruption on invasive plant performance and the underpinning mechanisms are poorly understood. Here, we used rainout shelters in an experimental field setting to test the hypothesis that drought reduces invasive plant performance by reducing microbial metabolic activity, resulting in decreased nitrogen flow to plants. We imposed growing season drought on populations of the exotic grass Microstegium vimineum, a widespread invasive plant in eastern deciduous forests, and quantified effects on aboveground and belowground biomass, and carbon (C) and nitrogen (N) cycling among plants, decomposers, and soil. Drought resulted in a 24% decrease in soil respiration, a 16% decrease in phenol oxidase enzyme activity, a 12% decrease in dissolved organic N concentration, and a decrease in the C:N ratio of particulate organic matter, suggesting reduced microbial metabolic activity and nutrient mining of soil organic matter. Drought also reduced aboveground Microstegium biomass 33% and increased Microstegium leaf C:N ratio, consistent with a decline in plant N uptake. We conclude that drought can reduce the performance of existing invasive species populations by suppressing plant-microbe interactions that increase nitrogen supply to plants, which may have consequences for the persistence of invasive plants under hydrologic change.

Phenotypic Study of Population and Distribution of the Poecilia reticulata (Cyprinodontiformes, Poeciliidae) from Kyiv Sewage System (Ukraine)

This paper presents the original data on studies of populations of guppies on the territory of Ukraine on the example of those of them surviving for many years in the drainage system of Kyiv. For 10 years, wild populations of guppies and their morphological features were studied in the warm water flows of the Bortnychi aeration station in Kyiv (2011–2020). During this period, the original “key” was developed to describe the morphology of their coloration peculiarities, which includes: total length, the number of pattern and coloration elements (4 types, 9 elements), pigmented area (light — orange, dark, pigmentation index), the shape and pigmentation of the tail (6 types) and its asymmetry At present, in the countries of Eastern Europe, the species is not adapted to any waters in the wild due to low winter temperatures, but these fish have become well established in sewage and other warm water bodies in urbanized areas (cities, towns, factories, etc.). We described the places where this invasive species had been found for many years, highlighting its key features. Thanks to GIS modelling, it was revealed that the existence of wild populations of guppies in Ukraine and Latvia is possible only in warm waters (currently mainly sewage systems of big cities) within anthropogenic territories. Such a key and study of relatively isolated populations of invasive species will provide a deeper understanding of micro-evolution of their morphological features (coloration) in isolation, help to track distribution of invasive species in a changing climate and provide material for comparison with possible similar invasions in areas heavily affected by military actions.

Recreational angler reporting as a tool for tracking the distribution of invasive Prussian carp (Carassius gibelio)

AbstractThe recent invasion of Carassius gibelio (commonly known as Prussian carp or Gibel carp) in freshwater environments in central Canada threatens native North American aquatic species and ecosystems. Accurate distribution information is essential for targeting control efforts but is challenging given the resources necessary to continually sample the species' potential distribution. We investigated the extent to which reports by recreational anglers—key resource users—could be used in a citizen science program to generate species distribution information, and factors affecting the accuracy of reporting for C. gibelio. Comparing the location of angler reports to the known distribution of C. gibelio generated by professional biological sampling across the region revealed that anglers can be a powerful resource for tracking an invasive species' distribution; 88% of the C. gibelio angler reports aligned with invaded watersheds (HUC‐8 [hydrological unit code 8], the second finest watershed unit) identified by professional biological sampling. For every report of C. gibelio received in a HUC‐8 area, the probability that area was invaded increased by more than 10 times (odds ratio = 10.26, ±95% CI: 4.4–29.7). Anglers' fish identification abilities were positively related to likelihood of reporting Carassius spp. (odds ratio = 2.52, ±95% CI:1.51–4.45). Anglers that fished more frequently were also more likely to have reported C. gibelio accurately (odds ratio = 1.00, ±95% CI: 0.99–1.01), although the mechanism behind this relationship is unclear. Our results suggest programs that engage recreational anglers in reporting could provide a cost‐effective alternative or complimentary tool for traditional Aquatic Invasive Species (AIS) population tracking.

MtDNA COI and Cyt b Analysis of Carassius auratus (Linnaeus, 1758) Species Living in Atatürk Dam Lake (Turkey)

Today, biological invasion is one of the leading threats to biodiversity and is an issue that is gaining more and more importance. In recent years, molecular techniques have been widely used in the identification and monitoring of invasive species in many parts of the world. This study aimed to detect the infested species, Carassius auratus, in Atatürk Dam Lake and to reveal the population status. For these purposes, 10 Carassius auratus specimens were randomly selected from Atatürk Dam Lake. After DNA isolation of the selected samples, mtDNA COI and cyt b gene regions were sequenced and analyzed. In this study, sequence analyzes of individuals belonging to the C. auratus species living in Atatürk Dam Lake were performed for the first time using mtDNA COI and cyt b markers. Analyzed sequence results were compared with databases and it was concluded that the results obtained for both mtDNA markers were compatible. No other variation was observed. When the results are evaluated as a whole, it is possible to say that this species has spread recently. In future studies, it is recommended to determine the invasive species populations that are intensely found in Atatürk Dam Lake and other lakes and to determine the necessary strategies to combat these invasive species