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At least 37 records · Page 2Linked to original sources
USGS2018

Salinity tolerance of non-native suckermouth armoured catfish (Loricariidae: Pterygoplichthys sp.) from Kerala, India

Loricariid catfishes of the genus Pterygoplichthys are native to South America and have been introduced in many localities around the world. They are freshwater fishes, but may also use low-salinity habitats such as estuaries for feeding or dispersal. Here we report results of a field survey and salinity-tolerance experiments for a population of Pterygoplichthys sp. collected in Kerala, India. In both chronic and acute salinity-tolerance trials, fish were able to withstand salinities up to 12 ppt with no mortality; however, fish transferred to salinities > 12 ppt did not survive. The experimental results provide evidence that nonnative Pterygoplichthys sp. are able to tolerate mesohaline conditions for extended periods, and can easily invade the brackish water ecosystems of the state. Further, Pterygoplichthys sp. from Kerala have greater salinity tolerance than other congeners. These data are vital to predicting the invasion of non-native fishes such as Pterygoplichthys spp. into coastal systems in Kerala and worldwide. This is particularly important as estuarine ecosystems are under threat of global climate change and sea-level rise. In light of the results of the present study and considering the reports of negative impacts of the species in invaded water bodies, management authorities may consider controlling populations and/or instituting awareness programmes to prevent the spread of this nuisance aquatic invasive species in Kerala.

Kerala↗
USGS2014

GIS-based rapid-assessment of bighead carp Hypophthalmichthys nobilis (Richardson, 1845) suitability in reservoirs

Broad-scale niche models are good for examining the potential for invasive species occurrences, but can fall short in providing managers with site-specific locations for monitoring. Using Oklahoma as an example, where invasive bighead carp (Hypophthalmichthys nobilis) are established in certain reservoirs, but predicted to be widely distributed based on broad-scale niche models, we cast bighead carp reproductive ecology in a site-specific geospatial framework to determine their potential establishment in additional reservoirs. Because bighead carp require large, long free-flowing rivers with suitable hydrology for reproduction but can persist in reservoirs, we considered reservoir tributaries with mean annual daily discharge ≥8.5 cubic meters per second (m3 /s) and quantified the length of their unimpeded portions. In contrast to published broad-scale niche models that identified nearly the entire state as susceptible to invasion, our site-specific models showed that few reservoirs in Oklahoma (N = 9) were suitable for bighead carp establishment. Moreover, this method was rapid and identified sites that could be prioritized for increased study or scrutiny. Our results highlight the importance of considering the environmental characteristics of individual sites, which is often the level at which management efforts are implemented when assessing susceptibility to invasion.

Oklahoma↗
USGS2023

Patterns of zero and nonzero counts suggest spatiotemporal distributions, aggregation, and dispersion of invasive carp

Bigheaded carp Hypophthalmichthys spp. are invasive species native to Asia expanding in the Mississippi River Basin in North America. An understanding of spatiotemporal distribution and aggregation of invasive carp is key to establishing when and where to focus surveillance designed to monitor expansion, and to managing harvest programs designed to curb population densities. We applied a two-stage hurdle model to assess three aspects of bigheaded carp ecology: distribution, relative abundance, and aggregation. Stage 1 was a binary 0/1 model that represented fish presence (p), and stage 2 was a truncated count distribution that had no zeros and included counts ≥ 1 only (C). Estimates of p and C varied temporally and spatially, but not in harmony and sometimes in opposing directions, indicating temporal and spatial swings in fish distributions and aggregations. Intense fish aggregations in channels in spring shown by low p’s and high C’s, eventually scattered by summer and fall as shown by high p’s and low C’s. An alternative but complementary interpretation of our observations is that p indexes incidence of aggregations and C indexes size of aggregations. Partitioning catch into its zero and nonzero components provided insight into population ecology that can inform development of monitoring and management of harvesting programs targeted at lessening potential effects of the invasion.

Alabama, Georgia, Kentucky, Mississippi, North Car↗
USGS2025

Combined effectiveness of light and bait to enhance trapping for monitoring and removal of invasive crayfish: Virile crayfish example

Invasive populations of crayfish are a major threat to native aquatic ecosystems around the world. The virile crayfish ( Faxonius virilis ) has become problematic outside of its native range in North America. Use of minnow traps is a common method used to detect the presence of and reduce invasive crayfish numbers. The primary goal of this study was to determine if the effectiveness and practicality of control through trapping for invasive crayfish could be significantly improved with the addition of lights. From this study, we found virile crayfish were attracted to white light and avoided blue light in the laboratory. In pond trials, traps with white or blue lights had catch per unit effort (CPUE) greater than traps without light, and traps with white lights had a CPUE nearly twice that of traps with blue lights. The addition of white lights to traps with food led to a nearly three-fold increase in CPUE than white light alone or two-fold for food bait alone. We found a continued decline in capture rates from the same pond over 3 days of trapping where captured crayfish were not returned to the pond. The continued decline in catch rate of new individuals suggests that our trapping may have been having a significant effect on the density of crayfish remaining in the pond. In addition, the size distribution of the crayfish collected during these trapping studies showed that the effort appears to be effective at collecting both juvenile and adult crayfish across almost all sizes. This would suggest that the combination of white light and bait is effective in the management of invasive crayfish populations.

Management of Biological Invasions↗
USGS2016

Observations of recruitment and colonization by tunicates and associated invertebrates using giant one-meter 2 recruitment plates at Woods Hole, Massachusetts

Large recruitment plates measuring 1 × 1 m were deployed over an 18-month period from September 2013 to March 2015 for the purpose of documenting recruitment and colonization processes of marine invertebrate species at Woods Hole, Massachusetts. Each side of two plates was subdivided into 16 subareas (25 × 25 cm), and an observational strategy was developed whereby, at approximately two-week intervals, a different subarea was cleaned. Using this approach, we were able to photographically document species recruitment and growth interactions. Water temperature records from the site show that steady warming and cooling between 3 and 20° C changed at a mean rate of 0.2 ° C d -1 . However, temperature changes during the coolest and warmest parts of the temperature cycle were highly variable. In 2014, between the first and last occurrence of 0° C, temperatures were ≤0° C 15 percent of the time, but in 2015 temperatures were ≤0° C 93 percent of the time. In 2014, between the first and last occurrence of 21° C, temperatures were ≥21° C 88 percent of the time, and this warm period correlated with the disappearance of the hydroid Ectopleura crocea , the solitary tunicates Ascidiella aspersa and Ciona intestinalis , and the 2013 generation of Botrylloides violaceus . In Woods Hole, large plates provided enough space to accommodate both fast- and slow-colonizing species, resulting in the establishment of a diverse assemblage that was observed over a long time period. The most successful colonizing species had relatively long reproductive and recruitment periods, grew rapidly, repelled settlement onto their surfaces by larvae of any species, defended themselves against overgrowth by any species, overwintered, and lived a long time. Of the three dominant species observed in this study, the colonial tunicates Didemnum vexillum and Botrylloides violaceus had these qualities; the encrusting colonial bryozoan Schizoporella unicornis had all but one, it grew more slowly than the others. Barnacles constituted the only biological substrate that was effectively colonized by other species, both by larval recruitment and overgrowth. In Woods Hole, after a substrate had become fully colonized, there was very little opportunity for new recruitment or colony growth until new substrate opened after the death of colonies and individuals and the disappearance of biogenic structures such as amphipod tubes. An understanding of colonization processes utilized by invasive species allows prediction of their potential effects on ecosystems in areas where they are not yet present.

Massachusetts↗
USGS2023

Use of physical blockers to control invasive red swamp crayfish in burrows

The red swamp crayfish Procambarus clarkii is native to the southeast United States but has successfully invaded nearly every continent around the world. Although physical, biological, and chemical controls are employed to reduce or eliminate populations in open-water systems, terrestrial burrows provide a potential refuge from aquatic control treatments. We conducted burrow trials to test whether two physical blocker treatments would kill P. clarkii in their burrows. Bentonite clay (a sealing agent) and expanding foam (an insulating sealant) were each applied to 37 crayfish burrows, and 36 burrows served as treatment controls (i.e., 110 total burrows). Burrows were excavated 48 hr after the application of the physical blockers to assess the status of crayfish in treated and control burrows. There was 74% mortality of crayfish in occupied burrows treated with bentonite clay, 62% in burrows treated with expanding foam, and 6% mortality in control burrows. We believe bentonite clay should continue to be field-tested; however, because expanding foam is toxic to aquatic organisms and is expected to persist in the environment, we do not believe it is a suitable physical blocker for the control of invasive crayfish in burrows. Bentonite clay applications likely will not need permits, will mitigate damage to banks and levees caused by burrowing crayfish, and can be used with other control agents such as pesticides. However, the use of physical blockers may be limited at field sites that have burrows with complex morphologies. We believe the use of bentonite clay to control invasive crayfish in terrestrial burrows will provide resource managers with an effective tool for their integrative pest management programs.

Management of Biological Invasions↗
USGS2011

Vulnerability of riparian ecosystems to elevated CO 2 and climate change in arid and semiarid western North America

Riparian ecosystems, already greatly altered by water management, land development, and biological invasion, are being further altered by increasing atmospheric CO 2 concentrations ([CO 2 ]) and climate change, particularly in arid and semiarid (dryland) regions. In this literature review, we (1) summarize expected changes in [CO 2 ], climate, hydrology, and water management in dryland western North America, (2) consider likely effects of those changes on riparian ecosystems, and (3) identify critical knowledge gaps. Temperatures in the region are rising and droughts are becoming more frequent and intense. Warmer temperatures in turn are altering river hydrology: advancing the timing of spring snow melt floods, altering flood magnitudes, and reducing summer and base flows. Direct effects of increased [CO 2 ] and climate change on riparian ecosystems may be similar to effects in uplands, including increased heat and water stress, altered phenology and species geographic distributions, and disrupted trophic and symbiotic interactions. Indirect effects due to climate-driven changes in streamflow, however, may exacerbate the direct effects of warming and increase the relative importance of moisture and fluvial disturbance as drivers of riparian ecosystem response to global change. Together, climate change and climate-driven changes in streamflow are likely to reduce abundance of dominant, native, early-successional tree species, favor herbaceous species and both drought-tolerant and late-successional woody species (including many introduced species), reduce habitat quality for many riparian animals, and slow litter decomposition and nutrient cycling. Climate-driven changes in human water demand and associated water management may intensify these effects. On some regulated rivers, however, reservoir releases could be managed to protect riparian ecosystem. Immediate research priorities include determining riparian species' environmental requirements and monitoring riparian ecosystems to allow rapid detection and response to undesirable ecological change.

Global Change Biology↗
USGS2023

Natives bite back: Depredation and mortality of invasive juvenile Burmese pythons (Python bivittatus) in the Greater Everglades Ecosystem

Burmese pythons (Python bivittatus Kuhl, 1820) are one of the world’s largest snake species, making them a highly successful and biologically damaging invasive predator in the Greater Everglades Ecosystem, Florida, USA. Though we have knowledge of python diet within this system, we understand very little of other interactions with native species. Effects native species have on invasive pythons, especially in the juvenile size class, are of particular interest as the prevalence of mortalities would inform potential population growth and trophic dynamics with native prey species. Native ophiophagous predators in Florida feed on smaller native snake species and it is unknown if they consistently recognize similarly sized juvenile invasive pythons as prey items. Using radiotelemetry, we found at least four native species within Big Cypress National Preserve that were implicated in juvenile python deaths, including three Florida cottonmouths (Agkistrodon conanti Gloyd, 1969), five American alligators (Alligator mississippiensis Daudin, 1802), one hispid cotton rat (Sigmodon hispidus Say and Ord, 1825), and three mesomammals. One mortality was the result of an attempt to subdue a prey item 106% the size of the python, constituting the largest predator:prey size ratio ever reported in this size class. This finding may indicate that phenotypic variation in individual juvenile pythons includes behavior that could be maladaptive within the novel Florida environment. Here we describe some of the first confirmed cases of non-anthropogenic mortality in juvenile Burmese pythons in Florida and present evidence that invasive pythons in this size class are now being incorporated into the diets of native species in its invasive range Burmese pythons (Python bivittatus Kuhl, 1820) are one of the world’s largest snake species, making them a highly successful and biologically damaging invasive predator in the Greater Everglades Ecosystem, Florida, USA. Though we have knowledge of python diet within this system, we understand very little of other interactions with native species. Effects native species have on invasive pythons, especially in the juvenile size class, are of particular interest as the prevalence of mortalities would inform potential population growth and trophic dynamics with native prey species. Native ophiophagous predators in Florida feed on smaller native snake species and it is unknown if they consistently recognize similarly sized juvenile invasive pythons as prey items. Using radiotelemetry, we found at least four native species within Big Cypress National Preserve that were implicated in juvenile python deaths, including three Florida cottonmouths (Agkistrodon conanti Gloyd, 1969), five American alligators (Alligator mississippiensis Daudin, 1802), one hispid cotton rat (Sigmodon hispidus Say and Ord, 1825), and three mesomammals. One mortality was the result of an attempt to subdue a prey item 106% the size of the python, constituting the largest predator:prey size ratio ever reported in this size class. This finding may indicate that phenotypic variation in individual juvenile pythons includes behavior that could be maladaptive within the novel Florida environment. Here we describe some of the first confirmed cases of non-anthropogenic mortality in juvenile Burmese pythons in Florida and present evidence that invasive pythons in this size class are now being incorporated into the diets of native species in its invasive range.

Florida↗
USGS2018

Correlating sea lamprey density with environmental DNA detections in the lab

Invasive sea lamprey (Petromyzon marinus Linnaeus, 1758) are currently managed by the Great Lakes Fishery Commission in an effort to reduce pest populations below levels that cause ecological damage. One technique to improve stream population assessments could be molecular surveillance in the form of environmental DNA (eDNA) monitoring. We developed and validated four probe-based quantitative polymerase chain reaction (qPCR) assays, then used two probes (cytb, nd1) to determine whether eDNA concentration was correlated with adult and larval sea lamprey density in the lab. We found a strong positive correlation between adult sea lamprey densities of 2, 20, and 200 individuals/2000L and eDNA concentrations in tanks using both assays (cytb, nd1). For larval laboratory tank density trials, eDNA concentrations were generally near our limit of quantification and there was no significant difference in copy numbers detected between larval sea lamprey densities of 1, 5, and 25 individuals/28L. Therefore, we examined detection probability rather than concentration with laboratory tank densities. We observed a trend of increasing detection probabilities with increased larval sea lamprey density that approached significance suggesting that when DNA copy numbers are low, detection rates may be more informative in predicting varying densities of larval sea lamprey. The ability to assess sea lamprey densities from a water sample could be a powerful tool to improve traditional assessment and stream ranking techniques. Further refinement of this method in the field may make eDNA surveillance of sea lamprey a reliable part of stream assessments. Rapid eDNA analysis from many streams may help focus traditional assessment efforts, thereby improving the efficiency of invasive sea lamprey control efforts.

Management of Biological Invasions↗
USGS2023

Evaluating the institutional and ecological effects of invasive species prevention policy: A case study from the U.S. Fish and Wildlife Service

Wildlife and natural resource institutions play key roles in invasive species monitoring and management. Paradoxically, the extensive fieldwork undertaken by these institutions and their partners may result in the inadvertent movement and spread of invasive species within and between sensitive ecosystems. In this work, we consider the potential effects of internal guidelines and policies designed to prevent the spread of invasive species by the field activities of management institutions and their partners. Such policies could be high-leverage tools for invasive species prevention, however, as large, complex organizations seek to implement policies to limit the spread of invasive species, it may be challenging to accommodate the wide diversity of potential invasion pathways and mitigation efforts facilitated via the programs, activities, and ecosystems they manage. Prevention policies may also be met with resistance due to the costs of implementation unless concrete benefits can be demonstrated. Assessing and communicating the effects of prevention policies could motivate improved implementation and adherence by institutional units and partners and could help inform adaptive policy changes. However, assessing the effectiveness of invasive species prevention presents a unique set of challenges, including incomplete data on invasive species distribution and pathways, that make it difficult to measure the effects of prevention efforts. In this work, we present a conceptual framework for evaluating institutional policies for invasive species prevention. We describe a flexible, multifaceted approach that considers policy implementation and adherence as well as ecological outcomes. We discuss potential application of this framework using a policy recently implemented by the Pacific Region of the U.S. Fish and Wildlife Service to prevent the introduction and spread of invasive species by service personnel and partners during field activities as a case study.

Management of Biological Invasions↗
USGS2024

Spatial distribution patterns of invasive silver carp can inform removal efforts in an oxbow lake of the Mississippi River

Oxbow lakes are highly productive waterbodies that host multiple life stages of many freshwater aquatic species. These lakes also provide foraging and rearing habitat to the invasive silver carp ( Hypophthalmichthys molitrix ) enabling populations to grow in biomass and abundance that can add propagule pressure to connected waterways and oxbows within the Mississippi River Basin. Ecologically these fish are undesirable because they overlap in diet and may compete for resources with native fishes and negatively impact recreational fisheries. Our goal was to evaluate silver carp distribution patterns in a major Mississippi River oxbow lake to inform removal programs and precision harvesting. We implanted 35 adult silver carp with acoustic tags and released them into the lake. Periodic tracking over 365 d revealed that fish were predominantly found in lake areas with water depths ranging from 2.0 to 5.9 m during all seasons, despite the availability of shallower and deeper water. Silver carp tended to aggregate in the wintertime (December–February) relative to other seasons. This information about lake area uses and seasonal aggregations could inform removal efforts in invaded waterbodies by exploiting natural behavioral and temporal vulnerabilities of this highly invasive and difficult-to-capture fish.

Mississippi↗
USGS2017

Using dissolved carbon dioxide to alter the behavior of invasive round goby

Fisheries managers need effective methods to limit the spread of invasive round goby Neogobius melanostomus in North America. Elevating carbon dioxide (CO 2 ) in water at pinch points of rivers (e.g., inside locks) is one approach showing potential to deter the passage of invasive fishes, such as bigheaded carps Hypophthalmichthys spp., but the effectiveness of this method to alter round goby behavior has not been determined. The goal for this study was to determine CO 2 concentrations that alter round goby behavior across a range of water temperatures. Free-swimming avoidance (voluntary response) and loss of equilibrium (involuntary response) were quantified by exposing round goby to increasing CO 2 concentrations at 5, 15, and 25 °C using a shuttle box choice arena and static tank. Water chemistry was measured concurrent with behavioral endpoints and showed that round goby avoided a threshold of 99–169 mg/L CO 2 (79,000–178,000 µatm) and lost equilibrium at 197–280 mg/L CO 2 (163,000–303,000 µatm). Approximately 50% lower CO 2 concentrations were found to modify behavior at 5 °C relative to 25 °C, suggesting greater effectiveness at lower water temperatures. We conclude that CO 2 modified round goby behavior and concentrations determined in this study are intended to guide field testing of CO 2 as an invasive fish deterrent.

Management of Biological Invasions↗
USGS2023

Evaluation of Ziram as an oral toxic bait chemical for control of grass carp Ctenopharyngodon idella

The grass carp, Ctenopharyngodon idella , is an invasive species in North America that has been recorded in 45 states with breeding populations in several major river basins. Established populations of grass carp have had cascading, negative effects on aquatic ecosystem structure and function. Oral piscicide baits have been examined as a potential method to manage invasive grass carp. Our goal was to examine the oral toxicity of the dimethyl-dithiocarbamate fungicide, Ziram, to grass carp. Three toxicity experiments used different carriers to deliver single Ziram doses ranging from 0.25 to 250 mg/kg by gavage. No acute mortality was observed when grass carp were gavaged with Ziram at the highest concentrations dissolved in ethanol at 40 mg/kg, suspended in dimethyl sulfoxide (DMSO) at 250 mg/kg, or suspended in polyethylene glycol (PEG) at 150 mg/kg. Ziram exposure through intraperitoneal injection resulted in acute mortality at 150 mg/kg potentially due to increased residence time in the peritoneal cavity and thereby greater opportunity for absorption. These results indicate that Ziram is acutely toxic to grass carp, however, additional research is required to formulate a successful novel grass carp toxicant that can be used to target the invasive species while minimizing effects on non-target fish species.

Management of Biological Invasions↗
USGS2015

Running a network on a shoestring: the Global Invasive Species Information Network

The Global Invasive Species Information Network (GISIN) was conceptualized in 2004 to aggregate and disseminate invasive species data in a standardized way. A decade later the GISIN community has implemented a data portal and three of six GISIN data aggregation models in the GISIN data exchange Protocol, including invasive species status information, resource URLs, and occurrence data. The portal is based on a protocol developed by representatives from 15 countries and 27 organizations of the global invasive species information management community. The GISIN has 19 data providers sharing 34,343 species status records, 1,693,073 occurrences, and 15,601 resource URLs. While the GISIN's goal is to be global, much of its data and funding are provided by the United States. Several initiatives use the GISIN as their information backbone, such as the Great Lakes Early Detection Network (GLEDN) and the North American Invasive Species Network (NAISN). Here we share several success stories and organizational challenges that remain.

Management of Biological Invasions↗
USGS2025

Predator effects on the survival of juvenile invasive carp in simulated backwater habitats

Numerous control methods are in use and under development to manage invasive carps in the United States. Commercial harvest, electric deterrents, and chemical toxicants, among other methods, are most efficient at targeting larger individuals. Research on methods to control recruitment of juvenile invasive carps has been limited. Our primary objective was to assess the vulnerability of juvenile invasive carp and common native forage species, gizzard shad ( Dorosoma cepedianum ) to native fish predators. Eighteen two-week long experiments, from April–October in 2015 and 2016, were conducted in experimental ponds with differing habitats (structure, vegetation, or open), simulating backwater habitats that are commonly used by juvenile invasive carps. Bowfin ( Amia calva ), channel catfish ( Icatalurus punctatus ), shortnose gar ( Lepisosteus platostomus ), hybrid striped bass ( Morone saxatilis × Morone chrysops ), largemouth bass ( Micropterus salmoides ), blue catfish ( Ictalurus furcatus ), flathead catfish ( Pylodictis olivaris ), walleye ( Sander vitreus ), northern pike ( Esox lucius ), and smallmouth bass ( Micropterus dolomieu ) were tested as predators of bighead carp ( Hypophthalmichthys nobilis ), silver carp ( Hypophthalmichthys molitrix ), grass carp ( Ctenopharyngodon idella ), and gizzard shad. We observed prey survival rates across seasons, habitats, and predator species. Invasive carp odds of survival varied from those of native gizzard shad between years. Hybrid striped bass, largemouth bass, smallmouth bass, and northern pike were effective predators of all tested prey species. Largemouth bass and smallmouth bass consumed bighead carp and silver carp over gizzard shad and grass carp (log OR < 0.5). Our results demonstrate the importance of habitat and cover availability, and that predator management may be a potential control method for juvenile invasive carps. Future research may consider effective predator densities, as well as studies in natural habitats.

Management of Biological Invasions↗
USGS2025

Invasive hitchhiking organisms on aquarium plants: An emerging pathway of introduction

The aquarium trade is a global industry responsible for the movement of live plants and animals, but it also serves as a major pathway for the introduction and spread of aquatic invasive species. Invasive species contribute to biodiversity loss, disrupt ecosystems, and can have widespread economic and societal impacts. A significant but poorly understood invasion risk in the plant aquarium trade is the transport of hitchhiking species, which are organisms unintentionally transported along with a species of primary interest in trade. Aquatic hitchhikers can persist in aquaria and later be released into the wild, potentially establishing invasive populations. While some studies have identified hitchhiking as a pathway for aquatic species spread, it remains largely unrecognized in international regulations. Increased awareness, triggered by incidents such as zebra mussels found in aquarium plants, highlights the need for further investigation into this emerging pathway of concern. As a response, we reviewed the current state of knowledge regarding aquatic plants in the aquarium trade as vectors for transporting invasive hitchhiking species, with a particular focus on how morphological complexity of plants influences associated hitchhikers. We found that although awareness of hitchhiking species in the aquarium trade is increasing, few studies have empirically examined aquarium plants as vectors for invasive species. Understanding this pathway can help to inform invasive species management around the plant aquarium trade and to keep aquarium organisms in a sustainable manner.

Management of Biological Invasions↗
USGS2016

Integrating early detection with DNA barcoding: species identification of a non-native monitor lizard (Squamata: Varanidae) carcass in Mississippi, U.S.A.

Early detection of invasive species is critical to increasing the probability of successful management. At the primary stage of an invasion, invasive species are easier to control as the population is likely represented by just a few individuals. Detection of these first few individuals can be challenging, particularly if they are cryptic or otherwise characterized by low detectability. The engagement of members of the public may be critical to early detection as there are far more citizen s on the landscape than trained biologists. However, it can be difficult to assess the credibility of public reporting, especially when a diagnostic digital image or a physical specimen in good condition are lacking. DNA barcoding can be used for verification when morphological identification of a specimen is not possible or uncertain (i.e., degraded or partial specimen). DNA barcoding relies on obtaining a DNA sequence from a relatively small fragment of mitochondrial DNA and comparing it to a database of sequences containing a variety of expertly identified species. He rein we report the successful identification of a degraded specimen of a non-native, potentially invasive reptile species ( Varanus niloticus ) via DNA barcoding, after discovery and reporting by a member of the public.

Mississippi↗
USGS2017

Can ozone be used to control the spread of freshwater Aquatic Invasive Species?

The introduction of aquatic invasive species to non-native habitats can cause negative ecological effects and also billions of dollars in economic damage to governments and private industries. Once aquatic invasive species are introduced, eradication may be difficult without adversely affecting native species and habitats, urging resource managers to find preventative methods to protect non-invaded areas. The use of ozone (O 3 ) as a non-physical barrier has shown promise as it is lethal to a wide range of aquatic taxa, requires a short contact time, and is relatively environmentally safe in aquatic systems when compared to other chemicals. However, before O 3 can be considered as an approach to prevent the spread of aquatic invasive species, its effects on non-target organisms and already established aquatic invasive species must be fully evaluated. A review of the current literature was conducted to summarize data regarding the effects of O 3 on aquatic taxa including fish, macroinvertebrates, zooplankton, phytoplankton, microbes, and pathogens. In addition, we assessed the practicality of ozone applications to control the movement of aquatic invasive species, and identified data gaps concerning the use of O 3 as a non-physical barrier in field applications.

Management of Biological Invasions↗