WorldWideScience

Sample records for aquatic invasive species

  1. Aquatic invasive species: Lessons from cancer research

    Science.gov (United States)

    Sepulveda, Adam; Ray, Andrew; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Gresswell, Robert E.; Gross, Jackson A.; Kershner, Jeffrey L.

    2014-01-01

    Aquatic invasive species are disrupting ecosystems with increasing frequency. Successful control of these invasions has been rare: Biologists and managers have few tools for fighting aquatic invaders. In contrast, the medical community has long worked to develop tools for preventing and fighting cancer. Its successes are marked by a coordinated research approach with multiple steps: prevention, early detection, diagnosis, treatment options and rehabilitation. The authors discuss how these steps can be applied to aquatic invasive species, such as the American bullfrog (Lithobates catesbeianus), in the Northern Rocky Mountain region of the United States, to expedite tool development and implementation along with achievement of biodiversity conservation goals.

  2. Climate Change and Aquatic Invasive Species (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Climate Change and Aquatic Invasive Species. This report reviews available literature on climate-change effects on aquatic invasive species (AIS) and examines state-level AIS management activities. Data on management ...

  3. Global ecological impacts of invasive species in aquatic ecosystems.

    Science.gov (United States)

    Gallardo, Belinda; Clavero, Miguel; Sánchez, Marta I; Vilà, Montserrat

    2016-01-01

    The introduction of invasive species, which often differ functionally from the components of the recipient community, generates ecological impacts that propagate along the food web. This review aims to determine how consistent the impacts of aquatic invasions are across taxa and habitats. To that end, we present a global meta-analysis from 151 publications (733 cases), covering a wide range of invaders (primary producers, filter collectors, omnivores and predators), resident aquatic community components (macrophytes, phytoplankton, zooplankton, benthic invertebrates and fish) and habitats (rivers, lakes and estuaries). Our synthesis suggests a strong negative influence of invasive species on the abundance of aquatic communities, particularly macrophytes, zooplankton and fish. In contrast, there was no general evidence for a decrease in species diversity in invaded habitats, suggesting a time lag between rapid abundance changes and local extinctions. Invaded habitats showed increased water turbidity, nitrogen and organic matter concentration, which are related to the capacity of invaders to transform habitats and increase eutrophication. The expansion of invasive macrophytes caused the largest decrease in fish abundance, the filtering activity of filter collectors depleted planktonic communities, omnivores (including both facultative and obligate herbivores) were responsible for the greatest decline in macrophyte abundance, and benthic invertebrates were most negatively affected by the introduction of new predators. These impacts were relatively consistent across habitats and experimental approaches. Based on our results, we propose a framework of positive and negative links between invasive species at four trophic positions and the five different components of recipient communities. This framework incorporates both direct biotic interactions (predation, competition, grazing) and indirect changes to the water physicochemical conditions mediated by invaders (habitat

  4. Mechanisms of aquatic species invasions across the SALCC - an update

    Science.gov (United States)

    Benson, Amy J.

    2014-01-01

    The USGS Nonindigenous Aquatic Species Database (NAS; nas.er.usgs.gov) is a comprehensive tool for demonstrating where and when nonindigenous species have been sighted across the U.S. Information in the database is used for state-level invasive species management plans, to focus monitoring efforts, for public education, predictive modeling, and for avoiding unintentional introductions during inter-basin water transfers.

  5. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.

    Science.gov (United States)

    Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics.

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

    Science.gov (United States)

    Buley, Riley P.; Hasler, Caleb T.; Tix, John A.; Suski, Cory D.; Hubert, Terrance D.

    2017-01-01

    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 (O3) 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 O3 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 O3 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 O3 as a non-physical barrier in field applications.

  7. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding

    NARCIS (Netherlands)

    Ghahramanzadeh, R.; Esselink, G.; Kodde, L.P.; Duistermaat, H.; Valkenburg, van J.L.C.H.; Marashi, S.H.; Smulders, M.J.M.; Wiel, van de C.C.M.

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to preven

  8. Interaction of species traits and environmental disturbance predicts invasion success of aquatic microorganisms.

    Directory of Open Access Journals (Sweden)

    Elvira Mächler

    Full Text Available Factors such as increased mobility of humans, global trade and climate change are affecting the range of many species, and cause large-scale translocations of species beyond their native range. Many introduced species have a strong negative influence on the new local environment and lead to high economic costs. There is a strong interest to understand why some species are successful in invading new environments and others not. Most of our understanding and generalizations thereof, however, are based on studies of plants and animals, and little is known on invasion processes of microorganisms. We conducted a microcosm experiment to understand factors promoting the success of biological invasions of aquatic microorganisms. In a controlled lab experiment, protist and rotifer species originally isolated in North America invaded into a natural, field-collected community of microorganisms of European origin. To identify the importance of environmental disturbances on invasion success, we either repeatedly disturbed the local patches, or kept them as undisturbed controls. We measured both short-term establishment and long-term invasion success, and correlated it with species-specific life-history traits. We found that environmental disturbances significantly affected invasion success. Depending on the invading species' identity, disturbances were either promoting or decreasing invasion success. The interaction between habitat disturbance and species identity was especially pronounced for long-term invasion success. Growth rate was the most important trait promoting invasion success, especially when the species invaded into a disturbed local community. We conclude that neither species traits nor environmental factors alone conclusively predict invasion success, but an integration of both of them is necessary.

  9. Mechanisms of aquatic species invasions across the South Atlantic Landscape Conservation Cooperative region

    Science.gov (United States)

    Benson, Amy J.; Stith, Bradley M.; Engel, Victor C.

    2016-12-15

    Invasive species are a global issue, and the southeastern United States is not immune to the problems they present. Therefore, various analyses using modeling and exploratory statistics were performed on the U.S. Geological Survey Nonindigenous Aquatic Species (NAS) Database with the primary objective of determining the most appropriate use of presence-only data as related to invasive species in the South Atlantic Landscape Conservation Cooperative (SALCC) region. A hierarchical model approach showed that a relatively small amount of high-quality data from planned surveys can be used to leverage the information in presence-only observations, having a broad spatial coverage and high biases of observer detection and in site selection. Because a variety of sampling protocols can be used in planned surveys, this approach to the analysis of presence-only data is widely applicable. An important part of the management of natural landscapes is the preservation of designated protected areas. When the hydrologic connection was considered in this analysis, the number of potential invaders that could spread to each protected area within the SALCC region was greatly increased, with a mean exceeding 30 species and the maximum reaching 57 species. Nearly all protected areas are hydrologically connected to at least 20 nonindigenous aquatic species. To examine possible factors which may contribute to nonindigenous aquatic species richness in the SALCC region, a set of exploratory statistics was employed. The best statistical model that included a combination of three anthropogenic variables (densities of housing, roads, and reservoirs) and two environmental variables (elevation range and longitude) explained approximately 62 percent of the variation in introduced species richness. Highest nonindigenous aquatic species richness occurred in the more upland, mountainous regions, where elevation range favored reservoirs and attracted urban centers. Lastly, patterns seen in a diffusion

  10. Integrated monitoring and information systems for managing aquatic invasive species in a changing climate

    Science.gov (United States)

    Lee, Henry; Reusser, Deborah A.; Olden, Julian D.; Smith, Scott S.; Graham, Jim; Burkett, Virginia; Dukes, Jeffrey S.; Piorkowski, Robert J.; Mcphedran, John

    2008-01-01

    Changes in temperature, precipitation, and other climatic drivers and sea-level rise will affect populations of existing native and non-native aquatic species and the vulnerability of aquatic environments to new invasions. Monitoring surveys provide the foundation for assessing the combined effects of climate change and invasions by providing baseline biotic and environmental conditions, although the utility of a survey depends on whether the results are quantitative or qualitative, and other design considerations. The results from a variety of monitoring programs in the United States are available in integrated biological information systems, although many include only non-native species, not native species. Besides including natives, we suggest these systems could be improved through the development of standardized methods that capture habitat and physiological requirements and link regional and national biological databases into distributed Web portals that allow drawing information from multiple sources. Combining the outputs from these biological information systems with environmental data would allow the development of ecological-niche models that predict the potential distribution or abundance of native and non-native species on the basis of current environmental conditions. Environmental projections from climate models can be used in these niche models to project changes in species distributions or abundances under altered climatic conditions and to identify potential high-risk invaders. There are, however, a number of challenges, such as uncertainties associated with projections from climate and niche models and difficulty in integrating data with different temporal and spatial granularity. Even with these uncertainties, integration of biological and environmental information systems, niche models, and climate projections would improve management of aquatic ecosystems under the dual threats of biotic invasions and climate change

  11. Forty years of experiments on aquatic invasive species: are study biases limiting our understanding of impacts?

    Directory of Open Access Journals (Sweden)

    Mads Thomsen

    2014-06-01

    Full Text Available Invasions by non-native species are a threat to biodiversity because invaders can impact native populations, communities and entire ecosystems. To manage this threat, it is necessary to have a strong mechanistic understanding of how non-native species affect local species and communities. We reviewed 259 published papers (1972–2012 that described field experiments quantifying the impact of aquatic non-native species, to examine whether various types of study biases are limiting this understanding. Our review revealed that invasion impacts had been experimentally quantified for 101 aquatic non-native species, in all major freshwater and marine habitats, on all continents except Antarctica and for most higher taxonomic groupings. Over one-quarter (26% of studies included tests for impacts on local biodiversity. However, despite this extensive research effort, certain taxa, habitats and regions remain poorly studied. For example, of the over one hundred species examined in previous studies, only one was a marine fish and only six were herbivores. Furthermore, over half (53% the studies were from the USA and two-thirds (66% were from experiments conducted in temperate latitudes. By contrast, only 3% of studies were from Africa and <2% from high latitudes. We also found that one-fifth (20% of studies were conducted in estuaries, but only 1% from coral reefs. Finally, we note that the standard procedure of pooling or not reporting non-significant treatments and responses is likely to limit future synthetic advancement by biasing meta-analysis and severely limiting our ability to identify non-native species with none or negligible ecological impacts. In conclusion, a future focus on poorly-studied taxa, habitats and regions, and enhanced reporting of results, should improve our understanding and management of impacts associated with aquatic non-native species.

  12. Sediment composition mediates the invasibility of aquatic ecosystems by a non-native Poaceae species

    Directory of Open Access Journals (Sweden)

    José Vitor Botter Fasoli

    2015-06-01

    Full Text Available Aim: To test the invasibility of aquatic ecosystems by an exotic species, we used the invasive macrophyte Urochloa arrecta, which has invaded many Neotropical waterbodies and has reduced biodiversity in these habitats. The extensive growth of this macrophyte can be related to its affinity for mud-rich sediments, which occur primarily in secondary river channels and lentic habitats.MethodsTo test this hypothesis, we cultivated U. arrecta in trays with different percentages of mud and we measured the sprout length and biomass of the plants after 75 days.ResultsOur results showed a positive and significant relationship between sediment mud percentage and nitrogen, phosphorus and organic matter. Both plant length and biomass increased significantly and continuously with increasing mud content, indicating that the growth of this species is not limited even at the highest levels of mud, which is shown to be toxic for other species of macrophytes. Thus, it is probable that sand-rich sites, such as river shores, are less vulnerable to invasion by this species than relatively mud-rich sites, such as lakes.ConclusionsThis finding indicates that relatively mud-rich ecosystems should be prioritised in monitoring programs to prevent invasion by this species. In addition, the slow development of this species in sandy sediments opens a potential window for its management, at least on small spatial scales. However, despite the reduced growth of U. arrecta in sand-rich sediments, this grass is able to grow in several types of sediments, which explains its spread in a variety of habitats in Neotropical freshwater ecosystems.

  13. Effects of Outreach on the Prevention of Aquatic Invasive Species Spread among Organism-in-Trade Hobbyists

    Science.gov (United States)

    Seekamp, Erin; Mayer, Jessica E.; Charlebois, Patrice; Hitzroth, Greg

    2016-11-01

    Releases of aquatic organisms-in-trade by aquarists, water gardeners, and outdoor pond owners have been identified as aquatic invasive species vectors within the Laurentian Great Lakes region. The trademarked U.S. Fish and Wildlife Service Habitattitude campaign was developed in 2004 to encourage self-regulation by these groups, but little is known about its effects. We surveyed organisms-in-trade hobbyists in the eight Great Lakes states (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin, USA) to assess their recognition of the Habitattitude campaign and their compliance with the campaign's recommended behaviors for organism purchase and disposal. Awareness of the Habitattitude campaign was low, but hobbyists that identified as both water gardeners and aquarium hobbyists were more aware of the campaign than individuals who participated in one of those hobbies. Engaged hobbyists (high aquatic invasive species awareness, concern, and knowledge) were significantly more likely than passive hobbyists (low aquatic invasive species awareness, concern, and knowledge) to make decisions about disposal of live organisms with the intention of preventing aquatic invasive species spread, were more likely to contact other hobbyists for disposal and handling advice, and were less likely to contact professionals, such as retailers. On the basis of our results, we suggest that compliance with recommended behaviors may be increased by fostering hobbyist networks; creating materials that both explain tangible, negative environmental impacts and list specific prevention behaviors; and disseminating these materials through trusted information sources and venues.

  14. Aquatic pollution may favor the success of the invasive species A. franciscana

    Energy Technology Data Exchange (ETDEWEB)

    Varó, I., E-mail: inma@iats.csic.es [Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595 Spain (Spain); Redón, S. [Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595 Spain (Spain); Garcia-Roger, E.M. [Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Burjassot (Spain); Amat, F.; Guinot, D. [Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595 Spain (Spain); Serrano, R. [Research Institute for Pesticides and Water (IUPA), Avda. Sos Baynat, s/n. University Jaume I, Castellón 12071 (Spain); Navarro, J.C. [Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595 Spain (Spain)

    2015-04-15

    Highlights: • Artemia species display an elevated tolerance to high ranges of chlorpyrifos. • A. franciscana survived better and its fecundity was less affected by chlorpyrifos. • The higher fecundity of A. franciscana is a selective advantage in colonization processes. • Higher survival and biological fitness in A. franciscana indicate out-competitive advantages. - Abstract: The genus Artemia consists of several bisexual and parthenogenetic sibling species. One of them, A. franciscana, originally restricted to the New World, becomes invasive when introduced into ecosystems out of its natural range of distribution. Invasiveness is anthropically favored by the use of cryptobiotic eggs in the aquaculture and pet trade. The mechanisms of out-competition of the autochthonous Artemia by the invader are still poorly understood. Ecological fitness may play a pivotal role, but other underlying biotic and abiotic factors may contribute. Since the presence of toxicants in hypersaline aquatic ecosystems has been documented, our aim here is to study the potential role of an organophosphate pesticide, chlorpyrifos, in a congeneric mechanism of competition between the bisexual A. franciscana (AF), and one of the Old World parthenogenetic siblings, A. parthenogenetica (PD). For this purpose we carried out life table experiments with both species, under different concentrations of the toxicant (0.1, 1 and 5 μg/l), and analyzed the cholinesterase inhibition at different developmental stages. The results evidence that both, AF and PD, showed an elevated tolerance to high ranges of chlorpyrifos, but AF survived better and its fecundity was less affected by the exposure to the pesticide than that of PD. The higher fecundity of AF is a selective advantage in colonization processes leading to its establishment as NIS. Besides, under the potential selective pressure of abiotic factors, such as the presence of toxicants, its higher resistance in terms of survival and biological

  15. Impact of Data Availability on Site Assessment and Predictive Behavior of Aquatic Invasive Species

    Science.gov (United States)

    2010-05-01

    melanstomus) Current distribution: In and around the Great Lakes and Illinois River. Round gobies are benthic fish that co-evolved with the zebra ... Fish . Aquat. Aci. 55:1759-1765. Ricciardi, A., F. G. Whoriskey, and J. B. Rasmussen. 1997. The role of the zebra mussel (Dreissena polymorpha) in...range expansion of some species. One of the few species for which extensive environmental tolerance data have been collected is the zebra mussel

  16. Development of biometric and environmental DNA standardized protocols for early detection and population assessment of aquatic invasive species for Arthur R. Marshall Loxahatchee National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal seeks to develop standard data collection techniques to support inventory and monitoring programs for aquatic invasive species (AIS) within National...

  17. How did this snail get here? Several dispersal vectors inferred for an aquatic invasive species

    NARCIS (Netherlands)

    Van Leeuwen, C.H.A.; Huig, N.; Van der Velde, G.; Van Alen, T.; Wagemaker, C.A.M.; Sherman, C.D.H.; Klaassen, M.R.J.; Figuerola, J.

    2013-01-01

    How species reach and persist in isolated habitats remains an open question in many cases, especially for rapidly spreading invasive species. This is particularly true for temporary freshwater ponds, which can be remote and may dry out annually, but may still harbour high biodiversity. Persistence i

  18. Effects of invasive species on plant communities: an example using submersed aquatic plants at the regional level

    Science.gov (United States)

    Submerged aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects in the hydrological regime, sedimentation, nutrient cycling and habitats of associated fauna. Modifications of aquatic plant communities, as for example through the introduction of invasive s...

  19. Developing strategies for aquatic invasive species early detection in the Great Lakes

    Science.gov (United States)

    As part of a webinar round-table discussion of invasive species and ballast water research, Dr. Trebitz will be giving a short overview of the research that she and co-PIs Jack Kelly, Joel Hoffman, and Greg Peterson are conducting in this area. Key findings from the 2005-2007 sam...

  20. Invasive species

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of management activities and research related to invasive species on Neal Smith National Wildlife Refuge between 1992 and 2009. As part of the...

  1. 76 FR 60863 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2011-09-30

    ... include: Commercial harvest of aquatic invasive species, State Aquatic Nuisance Species Management Plans...-Chair, Aquatic Nuisance Species Task Force, Acting Assistant Director--Fisheries and Habitat... Fish and Wildlife Service Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife...

  2. Invaders in hot water: a simple decontamination method to prevent the accidental spread of aquatic invasive non-native species.

    Science.gov (United States)

    Anderson, Lucy G; Dunn, Alison M; Rosewarne, Paula J; Stebbing, Paul D

    Watersports equipment can act as a vector for the introduction and spread of invasive non native species (INNS) in freshwater environments. To support advice given to recreational water users under the UK Government's Check Clean Dry biosecurity campaign and ensure its effectiveness at killing a range of aquatic INNS, we conducted a survival experiment on seven INNS which pose a high risk to UK freshwaters. The efficacy of exposure to hot water (45 °C, 15 min) was tested as a method by which waters users could 'clean' their equipment and was compared to drying and a control group (no treatment). Hot water had caused 99 % mortality across all species 1 h after treatment and was more effective than drying at all time points (1 h: χ(2) = 117.24, p water or drying, 6/7 of these species survived for 16 days, highlighting the importance of good biosecurity practice to reduce the risk of accidental spread. In an additional experiment the minimum lethal temperature and exposure time in hot water to cause 100 % mortality in American signal crayfish (Pacifastacus leniusculus), was determined to be 5 min at 40 °C. Hot water provides a simple, rapid and effective method to clean equipment. We recommend that it is advocated in future biosecurity awareness campaigns.

  3. Advancing capability for bioassessment using DNA metabarcoding: Application to aquatic invasive species monitoring

    Science.gov (United States)

    Characterizing biological communities by their constituent species is fundamental to biological monitoring and ecological condition assessment. Finding and identifying rare species is a long-standing challenge for monitoring programs. Nevertheless, conducting surveys that can des...

  4. Progress towards design elements for a Great Lakes-wide aquatic invasive species early detection network

    Science.gov (United States)

    Great Lakes coastal systems are vulnerable to introduction of a wide variety of non-indigenous species (NIS), and the desire to effectively respond to future invaders is prompting efforts towards establishing a broad early-detection network. Such a network requires statistically...

  5. 77 FR 61019 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2012-10-05

    ... aquatic invasive species. The agenda and other related meeting information are on the ANS Task Force Web... Species Task Force, Assistant Director--Fisheries and Habitat Conservation. BILLING CODE 4310-55-P ...: 134] Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife Service, Interior....

  6. An unusual case of seed dispersal in an invasive aquatic; yellow flag iris (Iris pseudacorus)

    Science.gov (United States)

    Understanding reproductive mode of invasive plants can help managers plan more efficacious control. Invasive aquatics typically reproduce primarily through vegetative means. Yellow flag iris is an invasive plant species often growing as an emergent aquatic. There have been contradictory reports of i...

  7. Invasive ornamental fish: a potential threat to aquatic biodiversity in peninsular India

    Directory of Open Access Journals (Sweden)

    J.D.M. Knight

    2010-02-01

    Full Text Available Alien fish find their way into newer habitats and ecosystems opportunistically. Once in a new habitat, these species try to occupy empty niches and compete with native species. An alien species becomes invasive wherever it has a competetive advantage over native species. Ecology of aquatic invasive alien species is rather poorly understood as most attention has been on invertebrates as that which spread through ballast water. Invasive alien species of fish that have taken advantage of the aquarium trade are emerging as the most important threats to fragile aquatic habitats. Regulations to this trade are rather weak and there is a general lack of data on the ecological impact of alien fish species despite the fact that a third of the world’s worst aquatic invasive species are aquarium or ornamental species.

  8. Invasion and predation in aquatic ecosystems

    Institute of Scientific and Technical Information of China (English)

    Judith S. WEIS

    2011-01-01

    This article reviews biological invasions in which predation (or its absence) plays a major role in the success of the invader.Examples are described in which the invader out-competes native species for the same food,and cases in which the invader consumes valued native species.In many instances,better predator avoidance by the invasive species or the absence of predators in the new habitat contributes to the success of the invaders; in other cases native or introduced predators appear to be able to keep the invasive species in check.A relatively new management approach in the US is the idea of adding another trophic level-to have humans act as the predators and consume the invasive species.This approach is being utilized in Florida and throughout the Caribbean against the lionfish,but could be extended to other fishes,as well as to various invasive crustaceans and mollusks.This idea is controversial,and current regulations prohibiting the possession of individuals of the invasive species (e.g.,mitten crabs or snakefish) would preclude the development of a fishery for them [Current Zoology 57 (5):613-624,2011].

  9. Fort Collins Science Center: Invasive Species Science

    Science.gov (United States)

    Stohlgren, Tom

    2004-01-01

    Invasive, non-native species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like "biological wildfires," they can quickly spread, and they affect nearly all terrestrial and aquatic ecosystems. Invasive species have become the greatest environmental challenge of the 21st century in terms of economic, environmental, and human health costs, with an estimated impact in the U.S. of over $138 billion per year. Managers of Department of the Interior and other public and private lands and waters rank invasive species as their top resource management problem.

  10. From molecules to management: adopting DNA-based methods for monitoring biological invasions in aquatic environments

    Science.gov (United States)

    Recent technological advances have driven rapid development of DNA-based methods designed to facilitate detection and monitoring of invasive species in aquatic environments. These tools promise to significantly alleviate difficulties associated with traditional monitoring approac...

  11. Bioterrorism and invasive species.

    Science.gov (United States)

    Chomel, B B; Sun, B

    2010-08-01

    The risk of dispersing invasive species, especially human pathogens, through acts of bioterrorism, cannot be neglected. However, that risk appears quite low in comparison with the risk of dispersing animal pathogens that could dramatically burden the agricultural economy of food animal producing countries, such as Australia and countries in Europe and North and South America. Although it is not directly related to bioterrorism, the intentional release of non-native species, particularly undesired companion animals or wildlife, may also have a major economic impact on the environment and, possibly, on animal and human health, in the case of accidental release of zoonotic agents.

  12. Nonindigenous Aquatic Species Database Marine Fishes

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Nonindigenous Aquatic Species Database (NAS) information resource is an established central repository for spatially referenced biogeographic accounts of...

  13. Development of biometric and environmental DNA standardized protocols for early detection and population assessment of aquatic invasive species for Arthur R. Marshall Loxahatchee NWR.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Our project proposed to integrate standard fisheries data collection techniques to support inventory and monitoring programs for fish communities, including aquatic...

  14. Dispersal of invasive species by drifting

    Institute of Scientific and Technical Information of China (English)

    M.C. VAN RIEL; G. VAN DER VELDE; A. BIJ DE VAATE

    2011-01-01

    Drifting can be an effective way for aquatic organisms to disperse and colonise new areas.Increasing connectivity between European large rivers facilitates invasion by drifting aquatic macroinvertebrates.The present study shows that high abundances of invasive species drift in the headstream of the river Rhine.Dikerogammarus villosus and Chelicorophium curvispinum represented up to 90% of the total of drifting macroinvertebrates.Drift activity shows seasonal and diel patterns.Most species started drifting in spring and were most abundant in the water column during the summer period.Drift activity was very low during the winter period.Diel patterns were apparent; most species,including D.villosus,drifted during the night.Drifting macroinvertebrates colonised stony substrate directly from the water column.D.villosus generally colonised the substrate at night,while higher numbers of C.curvispinum colonised the substrate during the day.It is very likely that drifting functions as a dispersal mechanism for crustacean invaders.Once waterways are connected,these species are no longer necessarily dependent on dispersal vectors other than drift for extending their distribution range [Current Zoology 57 (6):818-827,2011].

  15. Survey protocol for invasive species

    OpenAIRE

    Menza, Charles

    2009-01-01

    This protocol was developed by the Biogeography Branch of NOAA’s Center for Coastal Monitoring and Assessment to support invasive species research by the Papahānaumokuākea Marine National Monument. The protocol’s objective is to detect Carijoa riisei and Hypnea musciformis in deepwater habitats using visual surveys by technical divers. Note: This protocol is designed to detect the presence or absence of invasive species. A distinct protocol is required to collect information on abundance ...

  16. Role of diapause in dispersal and invasion success by aquatic invertebrates

    Directory of Open Access Journals (Sweden)

    Nicoletta RICCARDI

    2004-09-01

    Full Text Available Review of existing literature shows an important role of diapause in dispersal of aquatic invertebrates. There is evidence that among aquatic invertebrates, the role of diapause in dispersal can be important in crustaceans, specifically for species that produce resting eggs. Analysis of dispersal vectors of diapausing species revealed the increasing role of human-mediated vectors of species dispersal during last century (intentional and unintentional introductions, specifically associated with shipping in comparison with natural vectors (currents, wind, birds. Generally, the role of human-mediated vectors is most important for species dispersal across geographical barriers and into large aquatic ecosystems affected by shipping. Current human-mediated transport vectors increase rates of aquatic species introductions in many orders of magnitude in comparison with historical nature-driven species dispersal rates. Ability to develop diapausing resting stages facilitates species survival during movement across geographical barriers under extreme conditions, such as in ballast tanks of ships. Case studies for invasive species of Cladocera show that some invaders may possess adaptive life cycles, switching to the early prolonged gamogenetic reproduction, which facilitates their invasion success into novel ecosystems and further dispersal by both natural and human-mediated vectors.

  17. Chemical cues released by an alien invasive aquatic gastropod drive its invasion success.

    Directory of Open Access Journals (Sweden)

    Jacqueline L Raw

    Full Text Available BACKGROUND: Chemical cues provide aquatic organisms with sensory information that guides behavioural responses and thus interactions among themselves, each other and the environment. Chemical cues are considered important for predator avoidance, foraging, larval settlement and broadcast spawning in aquatic environments. However, the significance of their role as drivers of direct interactions between heterospecifics has been largely overlooked. METHODOLOGY/PRINCIPAL FINDINGS: A video camera and a demarcated arena were used in situ to record behavioural responses of three native gastropod species, Assiminea cf. capensis, Melanoides tuberculata and Coriandria durbanensis, exposed to treatments representing chemical cues released by a non-native invasive gastropod, Tarebia granifera. The responses were measured quantitatively as displacement and orientation of movement at locations in St Lucia Estuary, within the iSimangaliso Wetland Park, a UNESCO World Heritage Site on the east coast of South Africa. All native gastropods exhibited a negative taxis response to chemical cues released by T. granifera, while T. granifera individuals responded randomly to conspecifics. Displacement was measured relative to the source of the extract, the number of steps taken were determined with path analysis and orientation was determined from the mean (±95% CIs turning angles, with significant negative turning angles representing negative taxis. Responses to treatments corresponding to the environment and conspecifics were random and undirected, indicating kinesis. CONCLUSION/SIGNIFICANCE: This study presents evidence for interactions driven by chemical cues between a non-native invasive gastropod and several gastropods native to South Africa. The results indicate that chemical cues can facilitate invasion success as the behavioural response of native gastropods is to move away allowing additional food and space resources to become available to T. granifera.

  18. Invasion strategies in clonal aquatic plants: Are phenotypic differences caused by phenotypic plasticity or local adaptation?

    DEFF Research Database (Denmark)

    Riis, Tenna; Lambertini, Carla; Olesen, Birgit

    2010-01-01

    populations may facilitate ecotypic differentiation in the future cannot be excluded. These results thus indicate that invasive clonal aquatic plants adapt to new introduced areas by phenotypic plasticity. Inorganic carbon, nitrogen and phosphorous were important in controlling plant size of E. canadensis...... and L. major, but no other relationships between plant characteristics and habitat conditions were apparent. This implies that within-species differences in plant size can be explained by local nutrient conditions. All together this strongly suggests that invasive clonal aquatic plants adapt to a wide......Background and Aims: The successful spread of invasive plants in new environments is often linked to multiple introductions and a diverse gene pool that facilitates local adaptation to variable environmental conditions. For clonal plants, however, phenotypic plasticity may be equally important...

  19. Physiological Adaptation and Invasion Success: A Comparison of Native and Invasive Species of Bay Mussels in the Central California Hybrid Zone

    OpenAIRE

    Somero, George N.

    2005-01-01

    Invasive aquatic species can pose serious ecological and economic threats to coastal habitats. Although the mechanisms by which invasive species are introduced are generally well understood, and frequently caused by discharging ballast water, less is known about the physiological characterists that allow an invasive species to proliferate so successfully.

  20. Aquatic species project report: FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.M. [National Renewable Energy Lab., Golden, CO (United States); Sprague, S. [USDOE, Washington, DC (United States)

    1992-04-01

    This report summarizes the progress and research accomplishments of the Aquatic Species Project, which is managed by the National Renewable Energy Laboratory for the US Department of Energy. The project is focused on applying genetic engineering techniques to enhance the lipid, or oil, production of microalgae. Those lipids can be extracted and processed into high-energy liquid fuels such as diesel. Because microalgae require carbon dioxide, a major ``greenhouse`` gas, as a nutrient, project researchers also study the role that microalgae could play in a possible global climate change mitigation strategy.

  1. Aquatic species project report: FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.M. (National Renewable Energy Lab., Golden, CO (United States)); Sprague, S. (USDOE, Washington, DC (United States))

    1992-04-01

    This report summarizes the progress and research accomplishments of the Aquatic Species Project, which is managed by the National Renewable Energy Laboratory for the US Department of Energy. The project is focused on applying genetic engineering techniques to enhance the lipid, or oil, production of microalgae. Those lipids can be extracted and processed into high-energy liquid fuels such as diesel. Because microalgae require carbon dioxide, a major greenhouse'' gas, as a nutrient, project researchers also study the role that microalgae could play in a possible global climate change mitigation strategy.

  2. The Invasive Species Forecasting System

    Science.gov (United States)

    Schnase, John; Most, Neal; Gill, Roger; Ma, Peter

    2011-01-01

    The Invasive Species Forecasting System (ISFS) provides computational support for the generic work processes found in many regional-scale ecosystem modeling applications. Decision support tools built using ISFS allow a user to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of management concern, such as a national park, monument, forest, or refuge. This type of decision product helps resource managers plan invasive species protection, monitoring, and control strategies for the lands they manage. Until now, scientists and resource managers have lacked the data-assembly and computing capabilities to produce these maps quickly and cost efficiently. ISFS focuses on regional-scale habitat suitability modeling for invasive terrestrial plants. ISFS s component architecture emphasizes simplicity and adaptability. Its core services can be easily adapted to produce model-based decision support tools tailored to particular parks, monuments, forests, refuges, and related management units. ISFS can be used to build standalone run-time tools that require no connection to the Internet, as well as fully Internet-based decision support applications. ISFS provides the core data structures, operating system interfaces, network interfaces, and inter-component constraints comprising the canonical workflow for habitat suitability modeling. The predictors, analysis methods, and geographic extents involved in any particular model run are elements of the user space and arbitrarily configurable by the user. ISFS provides small, lightweight, readily hardened core components of general utility. These components can be adapted to unanticipated uses, are tailorable, and require at most a loosely coupled, nonproprietary connection to the Web. Users can invoke capabilities from a command line; programmers can integrate ISFS's core components into more complex systems and services. Taken together, these

  3. INVENTORY OF THE INVASIVE ALIE N PLANT SPECIES IN INDONESIA

    Directory of Open Access Journals (Sweden)

    SRI S UDARMIYATI T JITROSOEDIRDJO

    2005-01-01

    Full Text Available An inventory of the alien plant species in Indone sia based on the existing references and herbarium specimens concluded that 1936 alien plant species ar e found in Indonesia which belong to 187 families. Field studies should be done to get the complete figur es of alien plant species in Indonesia. Based on the existing figures of the plant species, the invasive alien plant species can be iden tified, followed by studies on the assessment of losses, biology, management and their possible utilizations. Alien plant species are imported to Indonesia for cultivation, collection of the botanical garden, as experimental plants or other curiosities. Aside from plants purposely imported, there are also introduced plant propagules conta-minating imported agricultural products. These alien plant species can be beneficial or have a potential of being invasive. The alien cultivated species consisted of 67% of the total number. More than half of the cultivated plants are ornamental plants. Some of th e species are naturalized or escaped from cultivation and become wild and invasive. Some other natura lized species, adapted well without any problems of invasion. There are 339 species or 17% of the species r ecorded as weeds. The highest record of weeds is found in the family of Poaceae (57 species, follo wed by Asteraceae (53 species and Cyperaceae (35 species. There are 6 families having more than 10 species of weeds: Amaranthaceae, Asteraceae, Cyperaceae, Euphorbiaceae, Poaceae, and Rubiaceae. Three families have more than 100 species: Asteraceae 162 species, Poaceae 120 species, and Papillionaceae 103 species. Five species of aquatic and 20 species of terrestrial plants considered as important alien plant species in Indonesia were identified and some of their distributions noted

  4. Status of Aquatic Non-indigenous Species in the St. Louis River System

    Science.gov (United States)

    As part of a study to develop recommendations for aquatic non-indigenous species (NIS) monitoring in Great Lakes areas at risk of invasion, we conducted comprehensive, multi-gear sampling in the lower St. Louis River in 2005-2007. This effort represents the most spatially and ta...

  5. Status of Aquatic Non-indigenous Species in the Duluth-Superior Harbor

    Science.gov (United States)

    As part of a study to develop recommendations for aquatic non-indigenous species (NIS) monitoring in Great Lakes areas at risk of invasion, we conducted comprehensive, multi-gear sampling in the Duluth, MN-Superior, WI harbor and lower St. Louis River in 2005-2007. This effort r...

  6. Aquatic beetle species and their distributions in Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ling; JIA Feng-long; Tursun Dilbar; ZHENG Zhe-min

    2009-01-01

    The species of aquatic beetles and their distributions in lotic and lentic habitats were investigated during July to August of 2005 and 2006 in Xinjiang Uygur Autonomous Region, China. A total of 66 species belonging to 7 beetle families (Dytiscidae, Gyrinidae, Haliplidae, Helophoridae, Noteridae, Hydraenidae, Hydrophilidae) are recorded, of which 16 are new records of aquatic beetles for China.

  7. 78 FR 60306 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2013-10-01

    ... Fish and Wildlife Service Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife Service... meeting of the Aquatic Nuisance Species (ANS) Task Force. The ANS Task Force's purpose is to develop and... Task Force will meet from 8 a.m. to 4:30 p.m. on Wednesday, November 6, through Thursday, November...

  8. Using scenarios to assess possible future impacts of invasive species in the Laurentian Great Lakes

    Science.gov (United States)

    Lauber, T. Bruce; Stedman, Richard C.; Connelly, Nancy A; Rudstam, Lars G.; Ready, Richard C; Poe, Gregory L; Bunnell, David; Hook, Tomas O.; Koops, Marten A.; Ludsin, Stuart A.; Rutherford, Edward S; Wittmann, Marion E.

    2016-01-01

    The expected impacts of invasive species are key considerations in selecting policy responses to potential invasions. But predicting the impacts of invasive species is daunting, particularly in large systems threatened by multiple invasive species, such as North America’s Laurentian Great Lakes. We developed and evaluated a scenario-building process that relied on an expert panel to assess possible future impacts of aquatic invasive species on recreational fishing in the Great Lakes. To maximize its usefulness to policy makers, this process was designed to be implemented relatively rapidly and consider a range of species. The expert panel developed plausible, internally-consistent invasion scenarios for 5 aquatic invasive species, along with subjective probabilities of those scenarios. We describe these scenarios and evaluate this approach for assessing future invasive species impacts. The panel held diverse opinions about the likelihood of the scenarios, and only one scenario with impacts on sportfish species was considered likely by most of the experts. These outcomes are consistent with the literature on scenario building, which advocates for developing a range of plausible scenarios in decision making because the uncertainty of future conditions makes the likelihood of any particular scenario low. We believe that this scenario-building approach could contribute to policy decisions about whether and how to address the possible impacts of invasive species. In this case, scenarios could allow policy makers to narrow the range of possible impacts on Great Lakes fisheries they consider and help set a research agenda for further refining invasive species predictions.

  9. Synergistic effects of the invasive Chinese tallow (Triadica sebifera) and climate change on aquatic amphibian survival.

    Science.gov (United States)

    Saenz, Daniel; Fucik, Erin M; Kwiatkowski, Matthew A

    2013-11-01

    Changes in climate and the introduction of invasive species are two major stressors to amphibians, although little is known about the interaction between these two factors with regard to impacts on amphibians. We focused our study on an invasive tree species, the Chinese tallow (Triadica sebifera), that annually sheds its leaves and produces leaf litter that is known to negatively impact aquatic amphibian survival. The purpose of our research was to determine whether the timing of leaf fall from Chinese tallow and the timing of amphibian breeding (determined by weather) influence survival of amphibian larvae. We simulated a range of winter weather scenarios, ranging from cold to warm, by altering the relative timing of when leaf litter and amphibian larvae were introduced into aquatic mesocosms. Our results indicate that amphibian larvae survival was greatly affected by the length of time Chinese tallow leaf litter decomposes in water prior to the introduction of the larvae. Larvae in treatments simulating warm winters (early amphibian breeding) were introduced to the mesocosms early in the aquatic decomposition process of the leaf litter and had significantly lower survival compared with cold winters (late amphibian breeding), likely due to significantly lower dissolved oxygen levels. Shifts to earlier breeding phenology, linked to warming climate, have already been observed in many amphibian taxa, and with most climate models predicting a significant warming trend over the next century, the trend toward earlier breeding should continue if not increase. Our results strongly suggest that a warming climate can interact with the effects of invasive plant species, in ways we have not previously considered, to reduce the survival of an already declining group of organisms.

  10. FY 1987 Aquatic Species Program: Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.A.; Sprague, S.

    1987-09-01

    The goal of the Department of Energy/Solar Energy Research Institute Aquatic Species Program is to develop the technology base to produce liquid fuels from microalagae at prices competitive with conventional alternatives. Microalgae are unusual plants that can accumulate large quantities of oil and can thrive in high-salinity water, which currently has no competing uses. The algal oils, in turn, are readily converted into gasoline and diesel fuels. The best site for successful microalgae production was determined to be the US desert Southwest, with potential applications to other warm areas. Aggressive research is needed, but the improvements required are attainable. The four prime research areas in the development of this technology are growth and production, engineering design, harvesting, and conversion. Algae are selected for three criteria: tolerance to environmental fluctuations, high growth rates, and high lipid production. From 1982 to 1986, the program collected more than 3000 strains of microalgae that are more than twice as tolerant to temperature and salinity fluctuation than the initial strains. Productivity has been increased by a factor of two in outdoor culture systems since 1982, and lipid content has also been increased from 20% of body weight in 1982 to greater than 66% of body weight in 1987. Research programs are ongoing in lipid biochemistry and genetic engineering so that ultimately strains can be modified and improved to combine their best characteristics. An outdoor test facility is being built in Roswell, New Mexico.

  11. The Invasive Plant Species Education Guide

    Science.gov (United States)

    Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

    2010-01-01

    To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

  12. Diversity of invasive species in Shanghai

    Directory of Open Access Journals (Sweden)

    Qingrou Zhang

    2013-11-01

    Full Text Available A list of invasive alien species (IAS is essential for initiating an analysis of the biological and ecological traits of such species and for improving our understanding of patterns of biological invasions. An inventory of IAS in Shanghai was prepared through a literature survey. A total of 212 IAS belonging to 63 orders and 87 families were recorded. Of these, 65% were plants, 29% were animals, and the rest were microorganisms. Dominant groups could be distinguished in both plant and animal groups. Species originating from the Americas made up 51% of the total, while 52% of plant species were introduced intentionally and 82% of animal species unintentionally. Of the invasive plants, 93% are distributed in highly disturbed habitats with rich resources, whereas 76% of invasive animals occur in storehouses and farmlands. The present information on diversity and ecological features of IAS is crucial for designing management strategies against the negative impacts of such species in Shanghai.

  13. DNA barcoding discriminates the noxious invasive species, floating pennywort (Hydrocotyle ranunculoides L.f.), from non-invasive relatives

    NARCIS (Netherlands)

    Wiel, van de C.C.M.; Schoot, van der J.; Valkenburg, van J.L.C.H.; Duistermaat, H.; Smulders, M.J.M.

    2009-01-01

    Floating pennywort (Hydrocotyle ranunculoides L.f.), a member of the plant family Araliaceae originating from North America, is an example of an invasive aquatic species posing serious problems to the management of waterways outside of its original distribution area in Australia and Western Europe.

  14. Transporting Ocean Viromes: Invasion of the Aquatic Biosphere

    Science.gov (United States)

    Kim, Yiseul; Aw, Tiong Gim; Rose, Joan B.

    2016-01-01

    Studies of marine viromes (viral metagenomes) have revealed that DNA viruses are highly diverse and exhibit biogeographic patterns. However, little is known about the diversity of RNA viruses, which are mostly composed of eukaryotic viruses, and their biogeographic patterns in the oceans. A growth in global commerce and maritime traffic may accelerate spread of diverse and non-cosmopolitan DNA viruses and potentially RNA viruses from one part of the world to another. Here, we demonstrated through metagenomic analyses that failure to comply with mid-ocean ballast water exchange regulation could result in movement of viromes including both DNA viruses and RNA viruses (including potential viral pathogens) unique to geographic and environmental niches. Furthermore, our results showed that virus richness (known and unknown viruses) in ballast water is associated with distance between ballast water exchange location and its nearest shoreline as well as length of water storage time in ballast tanks (voyage duration). However, richness of only known viruses is governed by local environmental conditions and different viral groups have different responses to environmental variation. Overall, these results identified ballast water as a factor contributing to ocean virome transport and potentially increased exposure of the aquatic bioshpere to viral invasion. PMID:27055282

  15. Impact of invasive aquatic macrophytes on the population and behavioral ecology of mosquitoes (Diptera: Culicidae)

    Science.gov (United States)

    A field survey, three outdoor cage enclosure experiments, and laboratory studies were conducted to elucidate the impact of the invasive aquatic weeds Eichhornia crassipes (floating water hyacinth), Ludwigia hexapetala (emergent water yellow-primrose), and Egeria densa (submersed Brazilian waterweed)...

  16. 75 FR 29359 - Invasive Species Advisory Committee

    Science.gov (United States)

    2010-05-25

    ... complex relationship between climate change and invasive species, opportunities for green jobs creation... Argonaut Hotel, 495 Jefferson Street at Hyde, San Francisco, California 94109-1314. The general session...

  17. Palmyra Atoll - Invasive Species Management 2008

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We initiated management of 3 species of plants that are introduced and invasive at Palmyra Atoll NWR. The work consisted of describing the distributions of these...

  18. 75 FR 61175 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2010-10-04

    ... Fish and Wildlife Service Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife Service... Species (ANS) Task Force. The meeting is open to the public. The meeting topics are identified in the SUPPLEMENTARY INFORMATION section. DATES: The ANS Task Force will meet from 8 a.m. to 5 p.m. on...

  19. Invasive macrozoobenthic species: are they a threat to the aquatic communities of German water bodies?%大型底栖动物入侵种:它们是否对德国水生动物群落构成威胁?

    Institute of Scientific and Technical Information of China (English)

    Melanie C. BECKMANN; 杨健; 徐跑

    2006-01-01

    在水体中发现大型底栖动物入侵种是一种世界范围普遍的现象.人类移动的同时将物品从一个大陆带到另一个大陆,这使许多水生动物物种能够突破自然的防线侵入到其他的区域和大陆.藉由人类现代的旅行方式,在不同区域间移动的物种数量显著增加,成功入侵种的数量也随之增多.成功入侵种需要具备一些特征,如可动性,小体型,适应性强和繁殖率高等,这些均有利于物种跨区域的入侵.当然,新生活环境也必须满足可适应的标准.对一个受人类活动破坏而丧失其原有物种的水环境来说,它对新物种入侵的抵抗力会很弱甚至缺乏.德国水体受人类活动的胁迫非常严重,许多自然水体受到的破坏已无法挽回,有些甚至已经完全成为了人工环境.这些水体由相互连接着的溪流河川网络组成,这很容易使新物种的入侵范围扩大.在外来物种的入侵面前,受人类活动胁迫和直接破坏的水体,比尚保持着天然环境状况的水体更加脆弱.%Macrozoobenthic invasion is a common phenomenon which appears throughout the world. Humans travel worldwide transporting materials from one continent to another. This enables many aquatic species to breach natural boundaries and invade environments in other regions and continents. With modern travel the number of species moving between different regions has increased considerably and so the number of successful aquatic invasions has increased. To be a successful invading species, there are some necessary traits. Mobility, small body size, adaptability and a high reproductive rate for example, would contribute to a successful cross-regional invasion. But the new host environment must fit some accommodating criteria. Environments that are depleted of their historical species due to human impact damage, may make little or no resistance to new organism invasions. German water bodies are under serious stress from human

  20. Invasive species unchecked by climate - response

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Duarte, Carlos M.;

    2012-01-01

    Hulme points out that observed rates of range expansion by invasive alien species are higher than the median speed of isotherm movement over the past 50 years, which in turn has outpaced the rates of climate-associated range changes of marine and terrestrial species. This is not surprising, given...

  1. Molecular Species Delimitation and Morphology of Aquatic and Sub-Aquatic Bugs (Heteroptera in Cameroon.

    Directory of Open Access Journals (Sweden)

    Solange Meyin A Ebong

    Full Text Available Aquatic and semi-aquatic bugs (Heteroptera represent a remarkable diversity and a resurging interest has been given to documenting at the species level these insects inhabiting Cameroon in Central Africa due to their potential implication in the transmission of the bacterium Mycobacterium ulcerans, the causal agent of Buruli ulcer, an emerging human disease. A survey was carried out over two years in Cameroon. Morphological analyses were done in two steps. A first step consisted in separating the specimens based on broadly shared characters into morphotypes. The specimens were then separated into two independent batches containing each the same representation of each morphotype. One batch (309 specimens was used by taxonomy experts on aquatic bugs for species level identification and/or to reconcile nymph with their corresponding adult species. The second batch (188 specimens was used to define species based on the COI DNA sequences (standard sequence used for "DNA barcoding" and using the Automatic Barcode Gap Discovery (ABGD method. The first morphological analysis step separated the specimens into 63 different morphotypes (49 adults and 14 nymphs, which were then found to belong to 54 morphological species in the infra-orders Gerromorpha and Nepomorpha based on the species-level morphological identification, and 41-45 putative molecular species according to the gap value retained in the ABGD. Integrating morphology and "DNA barcoding" reconciled all the specimens into 62 aquatic bug species in Cameroon. Generally, we obtained a good congruence between species a priori identified based on morphology from adult morphotypes and molecular putative species. Moreover, molecular identification has allowed the association of 86% of nymphs with adults. This work illustrates the importance of integrative taxonomy.

  2. SERI Aquatic Species Program: 1983 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    1984-03-01

    During 1983 research was carried out under three tasks: biological, engineering, and analysis. Biological research was aimed at screening for promising species of microalgae, macroalgae, and emergent plants that could be cultivated for energy products. Promising species were studied further to improve yields.

  3. Economics of Harmful Invasive Species: A Review

    Directory of Open Access Journals (Sweden)

    George Marbuah

    2014-07-01

    Full Text Available The purpose of this study is to review theoretical and empirical findings in economics with respect to the challenging question of how to manage invasive species. The review revealed a relatively large body of literature on the assessment of damage costs of invasive species; single species and groups of species at different geographical scales. However, the estimated damage costs show large variation, from less than 1 million USD to costs corresponding to 12% of gross domestic product, depending on the methods employed, geographical scale, and scope with respect to inclusion of different species. Decisions regarding optimal management strategies, when to act in the invasion chain and which policy to choose, have received much less attention in earlier years, but have been subject to increasing research during the last decade. More difficult, but also more relevant policy issues have been raised, which concern the targeting in time and space of strategies under conditions of uncertainty. In particular, the weighting of costs and benefits from early detection and mitigation against the uncertain avoidance of damage with later control, when the precision in targeting species is typically greater is identified as a key challenge. The role of improved monitoring for detecting species and their spread and damage has been emphasized, but questions remain on how to achieve this in practice. This is in contrast to the relatively large body of literature on policies for mitigating dispersal by trade, which is regarded as one of the most important vectors for the spread of invasive species. On the other hand, the literature on how to mitigate established species, by control or adaptation, is much more scant. Studies evaluating causes for success or failure of policies against invasive in practice are in principal non-existing.

  4. Induced pluripotent stem cell technology and aquatic animal species.

    Science.gov (United States)

    Temkin, Alexis M; Spyropoulos, Demetri D

    2014-06-01

    Aquatic animal species are the overall leaders in the scientific investigation of tough but important global health issues, including environmental toxicants and climate change. Historically, aquatic animal species also stand at the forefront of experimental biology, embryology and stem cell research. Over the past decade, intensive and high-powered investigations principally involving mouse and human cells have brought the generation and study of induced pluripotent stem cells (iPSCs) to a level that facilitates widespread use in a spectrum of species. A review of key features of these investigations is presented here as a primer for the use of iPSC technology to enhance ongoing aquatic animal species studies. iPSC and other cutting edge technologies create the potential to study individuals from "the wild" closer to the level of investigation applied to sophisticated inbred mouse models. A wide variety of surveys and hypothesis-driven investigations can be envisioned using this new capability, including comparisons of organism-specific development and exposure response and the testing of fundamental dogmas established using inbred mice. However, with these new capabilities, also come new criteria for rigorous baseline assessments and testing. Both the methods for inducing pluripotency and the source material can negatively impact iPSC quality and bourgeoning applications. Therefore, more rigorous strategies not required for inbred mouse models will have to be implemented to approach global health issues using individuals from "the wild" for aquatic animal species.

  5. Alabama's many endangered aquatic species are unprotected

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Newspaper article on the vulnerability of watercress darter and other fish species in Alabama after a significant fish kill in Roebuck Spring pond in 2008.

  6. 75 FR 15457 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2010-03-29

    ... Fish and Wildlife Service Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife Service... SUPPLEMENTARY INFORMATION section. DATES: The ANS Task Force will meet from 8 a.m. to 5 p.m. on Wednesday, May 5... place at the Holiday Inn Hotel & Convention Center by the Bay, 88 Spring Street, Portland, ME...

  7. Aquatic Species Project report, FY 1989--1990

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.M.; Sprague, S.

    1992-01-01

    This report summarizes the progress and research accomplishments of the Aquatic Species Project. The four articles included are summaries of individual research projects and are entered into the EDB as such. The goal of the Aquatic Species Project is to develop the technology base for large-scale production of oil-rich microalgae. The project is also developing methods to convert the microalgal lipids into liquid fuels needed for industry and transportation. Researchers in the Aquatics Species Project focus on the use of microalgae as a feedstock for producing renewable, high-energy liquid fuels such as diesel. It is important for the United States to develop alternative renewable oil sources because 42% of the current energy market in the United States is for liquid fuels, and 38% of these fuels are imported. In 1979, the US Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) initiated the Aquatic Species Project as part of the overall effort in biofuels. The project began to focus exclusively on fuels from microalgae in 1982. Estimates show that the technology being developed by the project can provide as much as 7% of the total current energy demand. The program`s basic premise is that microalgae, which have been called the most productive biochemical factories in the world, can produce up to 30 times more oil per unit of growth area than land plants. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  8. Modelling bioaccumulation of oil constituents in aquatic species

    NARCIS (Netherlands)

    Hoop, de L.; Huijbregts, M.A.J.; Schipper, A.M.; Veltman, K.; Laender, de F.; Viaene, K.P.J.; Klok, C.; Hendriks, A.J.

    2013-01-01

    Crude oil poses a risk to marine ecosystems due to its toxicity and tendency to accumulate in biota. The present study evaluated the applicability of the OMEGA model for estimating oil accumulation in aquatic species by comparing model predictions of kinetic rates (absorption and elimination) and bi

  9. Agricultural Warfare and Bioterrorism using Invasive Species

    Science.gov (United States)

    The chapter on Agricultural Warfare and Bioterrorism using Invasive Species is part of the book titled Pest Management and Phytosanitary Trade Barriers authored by Neil Heather (Australia) and Guy Hallman. The chapter attempts to briefly put the topic into context with phytosanitation. It presents...

  10. 78 FR 70317 - Invasive Species Advisory Committee

    Science.gov (United States)

    2013-11-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Office of the Secretary Invasive Species Advisory Committee AGENCY: Office of the Secretary, Interior... a meeting via teleconference, in lieu of physical travel, on Thursday, December 12, 2013 is...

  11. Arsenic and mercury in native aquatic bryophytes: differences among species.

    Science.gov (United States)

    Díaz, Santiago; Villares, Rubén; López, Jesús; Carballeira, Alejo

    2013-04-01

    This study investigated the capacities of five species of aquatic bryophytes to accumulate As and Hg from their natural habitats in rivers in Galicia (NW Spain). The distributions of the concentrations of both elements in all species were skewed to the right, with a higher incidence of extreme values in the As data, which may indicate a greater degree of contamination by this metalloid. There were no significant differences in the accumulation of either of the elements between the different species studied, which justifies their combined use as biomonitors of As and Hg, at least in the study area.

  12. Marine invasions by non-sea snakes, with thoughts on terrestrial-aquatic-marine transitions.

    Science.gov (United States)

    Murphy, John C

    2012-08-01

    Few species of snakes show extensive adaptations to aquatic environments and even fewer exploit the oceans. A survey of morphology, lifestyles, and habitats of 2552 alethenophidian snakes revealed 362 (14%) that use aquatic environments, are semi-aquatic, or aquatic; about 70 (2.7%) of these are sea snakes (Hydrophiinae and Laticaudinae). The ancient and aquatic family Acrochordidae contains three extant species, all of which have populations inhabiting brackish or marine environments, as well as freshwater. The Homalopsidae have the most ecologically diverse representatives in coastal habitats. Other families containing species exploiting saline waters with populations in freshwater environments include: the Dipsadidae of the western hemisphere, the cosmopolitan Natricidae, the African Grayinae, and probably a few Colubridae. Species with aquatic and semi-aquatic lifestyles are compared with more terrestrial (fossorial, cryptozoic, and arboreal) species for morphological traits and life histories that are convergent with those found in sea snakes; this may provide clues to the evolution of marine snakes and increase our understanding of snake diversity.

  13. Mercury uptake and accumulation by four species of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Kathleen [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)]. E-mail: skinnk@sage.edu; Wright, Nicole [NEIWPCC-NYSDEC, 625 Broadway, 4th Floor, Albany, NY 12233-3502 (United States)]. E-mail: ndwright@gw.dec.state.ny.us; Porter-Goff, Emily [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)

    2007-01-15

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water.

  14. Recognition of pyrrolizidine alkaloid esters in the invasive aquatic plant Gymnocoronis spilanthoides (Asteraceae)

    Science.gov (United States)

    Introduction – The freshwater aquatic plant Gymnocoronis spilanthoides (Senegal tea plant, jazmín del bañado, Falscher Wasserfreund) is an invasive plant in many countries. Behavioural observations of pyrrolizidine alkaloid-pharmacophagous butterflies suggested the presence of pyrrolizidine alkaloid...

  15. Initial Survey Instructions for Invasive Plant Species Mapping and Monitoring

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Initial survey instructions for Invasive Plant Species Mapping, 1.01a, and Invasive Plant Species Monitoring, 1.01b, at Fish Springs National Wildlife Refuge. These...

  16. Tualatin River - Invasive Species Management with Volunteers 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This grant has a strong focus on invasive species outreach and education with a supporting focus on active field management of native/invasive species. With more...

  17. SHELTER COMPETITION BETWEEN TWO INVASIVE CRAYFISH SPECIES: A LABORATORY STUDY

    Directory of Open Access Journals (Sweden)

    ALONSO F.

    2006-01-01

    Full Text Available Alien crayfishes represent a common threat to aquatic ecosystems. Their spread in Europe is leading to more frequent contacts between different invasive species populations. Shelter can be an important factor in the resulting interactions. A laboratory experiment was designed to analyse the competition for shelter in similarly sized males of two species that show an invasive behaviour in Spain, Pacifastacus leniusculus and Procambarus clarkii. We carried out 24 heterospecific, six-hour trials, with 30 min behavioural observations per hour. Most often, red swamp crayfish were both the first (70.8% and the long-term winner (62.5%. Usually, the long-term winner was the first winner. Whenever shelter was occupied, a passive behaviour by unsheltered individuals was more frequent in signal crayfish than in red swamp crayfish. When both were unsheltered, signal crayfish displayed more often a passive behaviour. Although the observed behaviour might be explained as the result of dominance by the red swamp crayfish over the signal crayfish, shelter availability and class, as well as different growth patterns and population size structures, could change the intensity and the outcome of the encounters in the wild, where signal crayfish usually reach larger sizes than red swamp crayfish.

  18. Invasive species information networks: Collaboration at multiple scales for prevention, early detection, and rapid response to invasive alien species

    Science.gov (United States)

    Simpson, Annie; Jarnevich, Catherine S.; Madsen, John; Westbrooks, Randy G.; Fournier, Christine; Mehrhoff, Les; Browne, Michael; Graham, Jim; Sellers, Elizabeth A.

    2009-01-01

    Accurate analysis of present distributions and effective modeling of future distributions of invasive alien species (IAS) are both highly dependent on the availability and accessibility of occurrence data and natural history information about the species. Invasive alien species monitoring and detection networks (such as the Invasive Plant Atlas of New England and the Invasive Plant Atlas of the MidSouth) generate occurrence data at local and regional levels within the United States, which are shared through the US National Institute of Invasive Species Science. The Inter-American Biodiversity Information Network's Invasives Information Network (I3N), facilitates cooperation on sharing invasive species occurrence data throughout the Western Hemisphere. The I3N and other national and regional networks expose their data globally via the Global Invasive Species Information Network (GISIN). International and interdisciplinary cooperation on data sharing strengthens cooperation on strategies and responses to invasions. However, limitations to effective collaboration among invasive species networks leading to successful early detection and rapid response to invasive species include: lack of interoperability; data accessibility; funding; and technical expertise. This paper proposes various solutions to these obstacles at different geographic levels and briefly describes success stories from the invasive species information networks mentioned above. Using biological informatics to facilitate global information sharing is especially critical in invasive species science, as research has shown that one of the best indicators of the invasiveness of a species is whether it has been invasive elsewhere. Data must also be shared across disciplines because natural history information (e.g. diet, predators, habitat requirements, etc.) about a species in its native range is vital for effective prevention, detection, and rapid response to an invasion. Finally, it has been our

  19. Aquatic Species Program review: proceedings of principal investigators meeting

    Energy Technology Data Exchange (ETDEWEB)

    1985-06-01

    The purpose of the Aquatic Species Program is to improve the productivity, conversion to fuels, and cost efficiency of aquatic plant culture technologies. The emphasis of the program is on developing a mass culture technology for cultivating oil-yielding microalgae in the American southwest. A technical and economic analysis indicated that such a concept would be feasible if (1) lipid yields from microalgae are improved, (2) there is sufficient saline water for large-scale development, and (3) microalgal lipids can be economically converted to conventional fuels. It was determined that fuels from microalgal lipids presented better options than converting the microalgal biomass to either alcohols or methane. All lipids can potentially be catalytically converted to gasoline, or the fatty acids can be converted to substitute diesel fuels. The Southwest has the necessary low, flat, underutilized lands, and carbon dioxide is available from either natural deposits or flue gas from industrial plants. The amount of saline water available will probably determine how much fuel can be produced from aquatic species, and this question should be answered during 1985. The largest constraint of this technology is the economical production of an oil-rich microalgal feedstock. The agenda for the review was divided into four sections: species selection and characterization, applied physiological studies, outdoor mass cultivation, and systems design and analysis. Papers from these presentations are included in these proceedings. Program advances were reported in the areas of species collection and selection, modulated light physiology, mass culture yields, harvesting of microalgae, mass culture facility design and analysis, and assessments on fuel options from microalgae. Separate abstracts have been prepared for each paper for inclusion in the Energy Data Base.

  20. New pasture plants intensify invasive species risk.

    Science.gov (United States)

    Driscoll, Don A; Catford, Jane A; Barney, Jacob N; Hulme, Philip E; Inderjit; Martin, Tara G; Pauchard, Aníbal; Pyšek, Petr; Richardson, David M; Riley, Sophie; Visser, Vernon

    2014-11-18

    Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks.

  1. Coevolution between native and invasive plant competitors: implications for invasive species management.

    Science.gov (United States)

    Leger, Elizabeth A; Espeland, Erin K

    2010-03-01

    Invasive species may establish in communities because they are better competitors than natives, but in order to remain community dominants, the competitive advantage of invasive species must be persistent. Native species that are not extirpated when highly invasive species are introduced are likely to compete with invaders. When population sizes and genetic diversity of native species are large enough, natives may be able to evolve traits that allow them to co-occur with invasive species. Native species may also evolve to become significant competitors with invasive species, and thus affect the fitness of invaders. Invasive species may respond in turn, creating either transient or continuing coevolution between competing species. In addition to demographic factors such as population size and growth rates, a number of factors including gene flow, genetic drift, the number of selection agents, encounter rates, and genetic diversity may affect the ability of native and invasive species to evolve competitive ability against one another. We discuss how these factors may differ between populations of native and invasive plants, and how this might affect their ability to respond to selection. Management actions that maintain genetic diversity in native species while reducing population sizes and genetic diversity in invasive species could promote the ability of natives to evolve improved competitive ability.

  2. Incidence and Management Costs of Freshwater Aquatic Nuisance Species at Projects Operated by the U.S. Army Corps of Engineers

    Science.gov (United States)

    2010-07-01

    the occurrence of ANS impacts (Yes or No) from freshwater algae, large aquatic plants, fish , zebra mussels, Asiatic clams, water fleas, crayfish...investment in research and development, especially for nuisance aquatic plants, fresh- water clams, and certain invasive fish species. Even so, aggregate...water hyacinths, hydrilla, common reed, sea lamprey, and the zebra mussel are especially notorious for their costly impacts on freshwater services

  3. Distribution of an invasive aquatic pathogen (viral hemorrhagic septicemia virus) in the Great Lakes and its relationship to shipping

    Science.gov (United States)

    Bain, Mark B.; Cornwell, Emily R.; Hope, Kristine M.; Eckerlin, Geofrey E.; Casey, Rufina N.; Groocock, Geoffrey H.; Getchell, Rodman G.; Bowser, Paul R.; Winton, James R.; Batts, William N.; Cangelosi, Allegra; Casey, James W.

    2010-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus found in fish from oceans of the northern hemisphere and freshwaters of Europe. It has caused extensive losses of cultured and wild fish and has become established in the North American Great Lakes. Large die-offs of wild fish in the Great Lakes due to VHSV have alarmed the public and provoked government attention on the introduction and spread of aquatic animal pathogens in freshwaters. We investigated the relations between VHSV dispersion and shipping and boating activity in the Great Lakes by sampling fish and water at sites that were commercial shipping harbors, recreational boating centers, and open shorelines. Fish and water samples were individually analyzed for VHSV using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and cell culture assays. Of 1,221 fish of 17 species, 55 were VHSV positive with highly varied qRT-PCR titers (1 to 5,950,000 N gene copies). The detections of VHSV in fish and water samples were closely associated and the virus was detected in 21 of 30 sites sampled. The occurrence of VHSV was not related to type of site or shipping related invasion hotspots. Our results indicate that VHSV is widely dispersed in the Great Lakes and is both an enzootic and epizootic pathogen. We demonstrate that pathogen distribution information could be developed quickly and is clearly needed for aquatic ecosystem conservation, management of affected populations, and informed regulation of the worldwide trade of aquatic organisms.

  4. Introduced and invasive cactus species: a global review

    Science.gov (United States)

    Novoa, Ana; Le Roux, Johannes J.; Robertson, Mark P.; Wilson, John R.U.; Richardson, David M.

    2015-01-01

    Understanding which species are introduced and become invasive, and why, are central questions in invasion science. Comparative studies on model taxa have provided important insights, but much more needs to be done to unravel the context dependencies of these findings. The cactus family (Cactaceae), one of the most popular horticultural plant groups, is an interesting case study. Hundreds of cactus species have been introduced outside their native ranges; a few of them are among the most damaging invasive plant species in the world. We reviewed the drivers of introductions and invasions in the family and seek insights that can be used to minimize future risks. We compiled a list of species in the family and determined which have been recorded as invasive. We also mapped current global distributions and modelled the potential global distributions based on distribution data of known invasive taxa. Finally, we identified whether invasiveness is phylogenetically clustered for cacti and whether particular traits are correlated with invasiveness. Only 57 of the 1922 cactus species recognized in this treatment have been recorded as invasive. There are three invasion hotspots: South Africa (35 invasive species recorded), Australia (26 species) and Spain (24 species). However, there are large areas of the world with climates suitable for cacti that are at risk of future invasion—in particular, parts of China, eastern Asia and central Africa. The invasive taxa represent an interesting subset of the total species pool. There is a significant phylogenetic signal: invasive species occur in 2 of the 3 major phylogenetic clades and in 13 of the 130 genera. This phylogenetic signal is not driven by human preference, i.e. horticultural trade, but all invasive species are from 5 of the 12 cactus growth forms. Finally, invasive species tend to have significantly larger native ranges than non-invasive species, and none of the invasive species are of conservation concern in their

  5. Native macrophyte density and richness affect the invasiveness of a tropical poaceae species.

    Directory of Open Access Journals (Sweden)

    Thaisa S Michelan

    Full Text Available The role of the native species richness and density in ecosystem invasibility is a matter of concern for both ecologists and managers. We tested the hypothesis that the invasiveness of Urochloa arrecta (non-native in the Neotropics is negatively affected by the species richness and abundance of native aquatic macrophytes in freshwater ecosystems. We first created four levels of macrophyte richness in a greenhouse (richness experiment, and we then manipulated the densities of the same native species in a second experiment (density experiment. When the native macrophytes were adults, fragments of U. arrecta were added, and their growth was assessed. Our results from the richness experiment corroborated the hypothesis of a negative relationship between the native species richness and the growth of U. arrecta, as measured by sprout length and root biomass. However, the resistance to invasion was not attributed to the presence of a particular native species with a greater competitive ability. In the density experiment, U. arrecta growth decreased significantly with an increased density of all five of the native species. Density strongly affected the performance of the Poaceae in a negative manner, suggesting that patches that are densely colonized by native macrophytes and less subject to disturbances will be more resistant to invasion than those that are poorly colonized and more commonly subjected to disturbances. Our density experiment also showed that some species exhibit a higher competitive ability than others (sampling effect. Although native richness and abundance clearly limit the colonization and establishment of U. arrecta, these factors cannot completely prevent the invasion of aquatic ecosystems by this Poaceae species.

  6. Native macrophyte density and richness affect the invasiveness of a tropical poaceae species.

    Science.gov (United States)

    Michelan, Thaisa S; Thomaz, Sidinei M; Bini, Luis M

    2013-01-01

    The role of the native species richness and density in ecosystem invasibility is a matter of concern for both ecologists and managers. We tested the hypothesis that the invasiveness of Urochloa arrecta (non-native in the Neotropics) is negatively affected by the species richness and abundance of native aquatic macrophytes in freshwater ecosystems. We first created four levels of macrophyte richness in a greenhouse (richness experiment), and we then manipulated the densities of the same native species in a second experiment (density experiment). When the native macrophytes were adults, fragments of U. arrecta were added, and their growth was assessed. Our results from the richness experiment corroborated the hypothesis of a negative relationship between the native species richness and the growth of U. arrecta, as measured by sprout length and root biomass. However, the resistance to invasion was not attributed to the presence of a particular native species with a greater competitive ability. In the density experiment, U. arrecta growth decreased significantly with an increased density of all five of the native species. Density strongly affected the performance of the Poaceae in a negative manner, suggesting that patches that are densely colonized by native macrophytes and less subject to disturbances will be more resistant to invasion than those that are poorly colonized and more commonly subjected to disturbances. Our density experiment also showed that some species exhibit a higher competitive ability than others (sampling effect). Although native richness and abundance clearly limit the colonization and establishment of U. arrecta, these factors cannot completely prevent the invasion of aquatic ecosystems by this Poaceae species.

  7. [Alien species invasion in Southern China and its countermeasures].

    Science.gov (United States)

    Fan, Jihui; Li, Jiang; Cheng, Genwei

    2005-03-01

    Alien species invasion may cause serious ecological damage, resulting in ecological crisis and biodiversity comedown, and further menacing existing human environment. At present, the invasion of alien species has brought very serious damage to China's environment and society. The direct annual loss of its agro-forestry industry accounts for 574 billion RMB. Taking the alien species in Southern China as an example, this paper analyzed the bio-invasion approaches, mechanics and damages, and aiming at the characters of invaded area and concerned ecosystems and species, proposed several prevention measurements, i.e., pay attention to the phenomena of bio-invasion and to the basic researches on it; intensify the legislation and establish scientific strategies for introducing alien species; enforce the quarantine on invasive species and establish countrywide monitoring system on alien species; enhance people's defending consciousness; and strengthen international cooperation and collaboration.

  8. Modelling bioaccumulation of oil constituents in aquatic species.

    Science.gov (United States)

    De Hoop, Lisette; Huijbregts, Mark A J; Schipper, Aafke M; Veltman, Karin; De Laender, Frederik; Viaene, Karel P J; Klok, Chris; Hendriks, A Jan

    2013-11-15

    Crude oil poses a risk to marine ecosystems due to its toxicity and tendency to accumulate in biota. The present study evaluated the applicability of the OMEGA model for estimating oil accumulation in aquatic species by comparing model predictions of kinetic rates (absorption and elimination) and bioconcentration factors (BCF) with measured values. The model was a better predictor than the means of the measurements for absorption and elimination rate constants, but did not outperform the mean measured BCF. Model estimates and measurements differed less than one order of magnitude for 91%, 80% and 61% of the absorption and elimination rates and BCFs of all oil constituents, respectively. Of the "potentially modifying" factors: exposure duration, biotransformation, molecular mass, and water temperature, the last two tended to influence the performance of the model. Inclusion of more explanatory variables in the bioaccumulation model, like the molecular mass, is expected to improve model performance.

  9. The role thermal physiology plays in species invasion.

    Science.gov (United States)

    Kelley, Amanda L

    2014-01-01

    The characterization of physiological phenotypes that may play a part in the establishment of non-native species can broaden our understanding about the ecology of species invasion. Here, an assessment was carried out by comparing the responses of invasive and native species to thermal stress. The goal was to identify physiological patterns that facilitate invasion success and to investigate whether these traits are widespread among invasive ectotherms. Four hypotheses were generated and tested using a review of the literature to determine whether they could be supported across taxonomically diverse invasive organisms. The four hypotheses are as follows: (i) broad geographical temperature tolerances (thermal width) confer a higher upper thermal tolerance threshold for invasive rather than native species; (ii) the upper thermal extreme experienced in nature is more highly correlated with upper thermal tolerance threshold for invasive vs. native animals; (iii) protein chaperone expression-a cellular mechanism that underlies an organism's thermal tolerance threshold-is greater in invasive organisms than in native ones; and (iv) acclimation to higher temperatures can promote a greater range of thermal tolerance for invasive compared with native species. Each hypothesis was supported by a meta-analysis of the invasive/thermal physiology literature, providing further evidence that physiology plays a substantial role in the establishment of invasive ectotherms.

  10. Emergent aquatics: stand establishment, management, and species screening

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, D.C.; Andrews, N.J.; Dubbe, D.R.; Garver, E.G.; Penko, M.; Read, P.E.; Zimmerman, E.S.

    1982-11-01

    Several emergent aquatic species have been identified as potential biomass crops, including Typha spp. (cattail), Scirpus spp. (rush), Sparganium spp. (bur reed), and Phragmites (reed). This report discusses first year results from studies of stand establishment and management, Typha nutrient requirements, wetland species yield comparisons, and Typha micropropagation. In a comparison of the relative effectiveness of seed, seedlings, and rhizomes for stand establishment, rhizomes appeared to be more consistent and productive under a wire variety of conditions. Both rhizomes and seedling established plots grew successfully on excavated peatland sites. First season results from a multiyear fertilizer rate experiment indicate that fertilizer treatment resulted in significantly increased tissue nutrient concentrations which should carry over into subsequent growing seasons. Shoot density and belowground dry weight were also significantly increased by phosphorus + potassium and potassium applications, respectively. First season yields of selected wetland species from managed paddies generally were comparable to yields reported from natural stands. Several particularly productive clones of Typha spp. have been identified. A method of establishing Typha in tissue culture is described.

  11. Identifying Invasive Species Educational Needs in Florida: Opportunities for Extension

    Science.gov (United States)

    Huang, Pei-wen; Lamm, Alexa J.

    2016-01-01

    Florida's ecology has been adversely affected by invasive species. In Florida, a study was conducted to explore opportunities for Extension educators to contribute to combating the issue of invasive species. Florida residents' responses were captured through the use of an online public opinion survey. The findings revealed a need for invasive…

  12. 78 FR 29378 - Aquatic Nuisance Species Task Force; Public Teleconference/Webinar

    Science.gov (United States)

    2013-05-20

    ... Fish and Wildlife Service Aquatic Nuisance Species Task Force; Public Teleconference/ Webinar AGENCY..., announce a public teleconference/webinar of the Aquatic Nuisance Species Task Force (ANS Task Force). The... disseminate related information. DATES: Teleconference/webinar: Monday June 17, 2013, from 1 p.m. to 4...

  13. Aquatic Species Program Review: Proceedings of the March 1983 Principal Investigators Meeting

    Energy Technology Data Exchange (ETDEWEB)

    1983-06-01

    The Aquatic Species Program (ASP) addresses the utilization of plant biomass that naturally occurs in wetland or submerged areas. Processes are being developed through this program to make use of such aquatic species, capitalizing on their inherent capacity for rapid growth as well as their extraordinary chemical compositions.

  14. Proceedings of the Subcontractors' Review Meeting: Aquatic Species Program

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The Aquatic Species Program (ASP) addresses the utilization of plant biomass that naturally occurs in wetland or submerged areas. Processes are being developed through this program to make use of such aquatic species, capitalizing on their inherent capacity for rapid growth as well as their extraordinary chemical compositions.

  15. On the well posedness and further regularity of a diffusive three species aquatic model

    KAUST Repository

    Parshad, R.D.

    2012-01-01

    We consider Upadhay\\'s three species aquatic food chain model, with the inclusion of spatial spread. This is a well established food chain model for the interaction of three given aquatic species. It exhibits rich dynamical behavior, including chaos. We prove the existence of a global weak solution to the diffusive system, followed by existence of local mild and strong solution.

  16. Dna c-values of 20 invasive alien species and 3 native species in south china

    Directory of Open Access Journals (Sweden)

    Gong Ni

    2014-01-01

    Full Text Available Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lowest DNA C-value among the perennials, indicating that native species with low nuclear content may also possess an invasive potential.

  17. Capabilities of Seven Species of Aquatic Macrophytes for Phytoremediation of Pentachlorophenol Contaminated Sediment

    Science.gov (United States)

    Zhao, Liangyuan; Guo, Weijie; Li, Qingyun; Li, Huan; Zhao, Weihua; Cao, Xiaohuan

    2017-01-01

    Sediments are regarded as the ultimate sink of pentachlorophenol(PCP) in aquatic environment, and capabilities of seven species of aquatic macrophytes for remediating PCP contaminated sediment were investigated. Seven species of aquatic macrophytes could significantly accelerate the degradation of PCP in sediments. Among all, canna indica L., Acorus calamus L. and Iris tectorum Maxim. can be used as efficient alternative plants for remediation of PCP contaminated sediment, which attained 98%, 92% and 88% of PCP removal in sediments, respectively. PCP was detected only in root tissues and the uptake was closely related to the root lipid contents of seven plants. The presence of seven aquatic macrophytes significantly increased microbial populations and the activities of dehydrogenase compared with control sediments, indicating that rhizosphere microorganism played important role in the remediation process. In conclusion, seven species of aquatic macrophytes may act as promising tools for the PCP phytoremediation in aquatic environment, especially Canna indica L., Acorus calamus L. and Iris tectorum Maxim.

  18. Vision of a cyberinfrastructure for nonnative, invasive species management

    Science.gov (United States)

    2008-01-01

    Although the quantity of data on the location, status, and management of invasive species is ever increasing, invasive species data sets are often difficult to obtain and integrate. A cyberinfrastructure for such information could make these data available for Internet users. The data can be used to create regional watch lists, to send e-mail alerts when a new species enters a region, to construct models of species' current and future distributions, and to inform management. Although the exchange of environmental data over the Internet in the form of raster data is maturing, and the exchange of species occurrence data is developing quickly, there is room for improvement. In this article, we present a vision for a comprehensive invasive species cyberinfrastructure that is capable of accessing data effectively, creating models of invasive species spread, and distributing this information.

  19. Lianas as invasive species in North America: Chapter 28

    Science.gov (United States)

    Leicht-Young, Stacey A.; Pavlovic, Noel B.

    2015-01-01

    Liana diversity is typically low in the temperate zones; however, the influx of non-native invasive liana species in North America has increased local diversity at the expense of native habitats and species. Some of the most illustrative studies of invasive lianas in temperate North America compared the biological traits of invasive lianas with native congeners or ecological analogs. The majority of these studies focused on two species, Celastrus orbiculatus (oriental bittersweet) and Lonicera japonica (Japanese honeysuckle). Temperate zone lianas generally have higher photosynthetic rates than other early successional species and their host trees. Invasive lianas are having an increasing impact on the dynamics and trajectories of North American plant communities. They often exhibit superior growth and survival compared to their native counterparts, and in some cases, invasive lianas may directly contribute to the decline of their native correlates.

  20. Adaptive invasive species distribution models: A framework for modeling incipient invasions

    Science.gov (United States)

    Uden, Daniel R.; Allen, Craig R.; Angeler, David G.; Corral, Lucia; Fricke, Kent A.

    2015-01-01

    The utilization of species distribution model(s) (SDM) for approximating, explaining, and predicting changes in species’ geographic locations is increasingly promoted for proactive ecological management. Although frameworks for modeling non-invasive species distributions are relatively well developed, their counterparts for invasive species—which may not be at equilibrium within recipient environments and often exhibit rapid transformations—are lacking. Additionally, adaptive ecological management strategies address the causes and effects of biological invasions and other complex issues in social-ecological systems. We conducted a review of biological invasions, species distribution models, and adaptive practices in ecological management, and developed a framework for adaptive, niche-based, invasive species distribution model (iSDM) development and utilization. This iterative, 10-step framework promotes consistency and transparency in iSDM development, allows for changes in invasive drivers and filters, integrates mechanistic and correlative modeling techniques, balances the avoidance of type 1 and type 2 errors in predictions, encourages the linking of monitoring and management actions, and facilitates incremental improvements in models and management across space, time, and institutional boundaries. These improvements are useful for advancing coordinated invasive species modeling, management and monitoring from local scales to the regional, continental and global scales at which biological invasions occur and harm native ecosystems and economies, as well as for anticipating and responding to biological invasions under continuing global change.

  1. Biodiesel/Aquatic Species Project report, FY 1992

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.; Jarvis, E.; Dunahay, T.; Roessler, P.; Zeiler, K. [National Renewable Energy Lab., Golden, CO (United States); Sprague, S. [USDOE, Washington, DC (United States)

    1993-05-01

    The primary goal of the Biodiesel/Aquatic Species Project is to develop the technology for growing microalgae as a renewable biomass feedstock for the production of a diesel fuel substitute (biodiesel), thereby reducing the need for imported petroleum. Microalgae are of interest as a feedstock because of their high growth rates and tolerance to varying environmental conditions, and because the oils (lipids) they produce can be extracted and converted to substitute petroleum fuels such as biodiesel. Microalgae can be grown in arid and semi-arid regions with poor soil quality, and saline water from aquifers or the ocean can be used for growing microalgae. Biodiesel is an extremely attractive candidate to fulfill the need for a diesel fuel substitute. Biodiesel is a cleaner fuel than petroleum diesel; it is virtually free of sulfur, and emissions of hydrocarbons, carbon monoxide, and particulates during combustion are significantly reduced in comparison to emissions from petroleum diesel. Biodiesel provides essentially the same energy content and power output as petroleum-based diesel fuel.

  2. Biodiesel from aquatic species. Project report: FY 1993

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.M.; Sprague, S.; Jarvis, E.E.; Dunahay, T.G.; Roessler, P.G.; Zeiler, K.G.

    1994-01-01

    Researchers in the Biodiesel/Aquatic Species Project focus on the use of microalgae as a feedstock for producing renewable, high-energy liquid fuels. The program`s basic premise is that microalgae, which have been called the most productive biochemical factories in the world, can produce up to 30 times more oil per unit of growth area than land plants. It is estimated that 150 to 400 barrels of oil per acre per year (0.06 to 0.16 million liters/hectar) could be produced with microalgal oil technology. Initial commercialization of this technology is envisioned for the desert Southwest because this area provides high solar radiation and offers flat land that has few competing uses (hence low land costs). Similarly, there are large saline aquifers with few competing uses in the region. This water source could provide a suitable, low-cost medium for the growth of many microalgae. The primary area of research during FY 1993 was the effort to genetically improve microalgae in order to control the timing and magnitude of lipid accumulation. Increased lipid content will have a direct effect on fuel price, and the control of lipid content is a major project goal. The paper describes progress on the following: culture collection; molecular biology of lipid biosynthesis; microalgal transformation; and environmental, safety, and health and quality assurance.

  3. Turnbull - Invasive Species Education and EDRR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers have since 2004 undertaken a refuge–wide, GPS-based invasive plant survey and assisted with our Early Detection and Rapid Response Program (EDRRP). Past...

  4. Economic essays on marine invasive species and international fisheries agreements

    NARCIS (Netherlands)

    Walker, A.N.

    2016-01-01

    This thesis is divided into two parts, as explained in Chapter 1, which focus on different aspects of marine ecological change. Part A considers marine Invasive Alien Species (IAS), which are taxa introduced outside of their native range. The detrimental consequences of invasions for human welfare n

  5. 76 FR 32135 - National Forest System Invasive Species Management Policy

    Science.gov (United States)

    2011-06-03

    ... Web/Internet Web site http://www.regulations.gov or mail written comments to Director, Rangeland...; cleaning, scraping, or otherwise removing invasive species attached to equipment, structures, or...

  6. Oregon Islands - Invasive Species Removal at Coquille Point Coastal Bluff

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The proposed project is a part of the Refuge invasive species management program and will help achieve goals and priority habitats objectives identified in the...

  7. Possibility to implement invasive species control in Swedish forests.

    Science.gov (United States)

    Pettersson, Maria; Strömberg, Caroline; Keskitalo, E Carina H

    2016-02-01

    Invasive alien species constitute an increasing risk to forestry, as indeed to natural systems in general. This study reviews the legislative framework governing invasive species in the EU and Sweden, drawing upon both a legal analysis and interviews with main national level agencies responsible for implementing this framework. The study concludes that EU and Sweden are limited in how well they can act on invasive species, in particular because of the weak interpretation of the precautionary principle in the World Trade Organisation and Sanitary and Phytosanitary agreements. In the Swedish case, this interpretation also conflicts with the stronger interpretation of the precautionary principle under the Swedish Environmental Code, which could in itself provide for stronger possibilities to act on invasive species.

  8. Tualatin River - Invasive Species Identification, Control and Monitoring 2007

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Project goals were to train volunteers to conduct invasive species mapping using GPS and GIS technology. Volunteers were able to map 450 acres on the Atflati Unit of...

  9. Willamette Valley - Invasive Species Management with Volunteers 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with refuge staff to survey for and treat invasive species on the Willamette Valley Refuges (Ankeny, Baskett Slough and WL Finley NWR). False brome...

  10. Willamette Valley - Invasive Species Management with Volunteers 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with staff to survey for and treat 17 different invasive species within the Willamette Valley Refuges (Ankeny, Baskett Slough and William L....

  11. Willamette Valley - Invasive Species Management with Volunteers 2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with refuge staff to survey for and treat invasive species on the Willamette Valley Refuges (Ankeny, Baskett Slough and WL Finley NWR). Scotch...

  12. Willamette Valley - Invasive Species Management with Volunteers 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with staff to map and control invasive species within the Willamette Valley National Wildlife Refuge Complex refuges (William L. Finley, Ankeny,...

  13. Sheldon-Hart - Invasive Species Inventory, Monitoring, and Control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Beginning in 2009/2010, the Sheldon/Hart Refuge Complex refocused efforts to inventory, monitor, and control invasive plant species to allow for better adaptive...

  14. Mid-Columbia - Invasive Species Management with Volunteers 2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Project will initiate a program for the early detection, monitoring and mapping of invasive species on McNary and Umatilla NWR's using Refuge volunteers. The initial...

  15. Ohio Aquatic Gap Analysis-An Assessment of the Biodiversity and Conservation Status of Native Aquatic Animal Species

    Science.gov (United States)

    Covert, S. Alex; Kula, Stephanie P.; Simonson, Laura A.

    2007-01-01

    The goal of the GAP Analysis Program is to keep common species common by identifying those species and habitats that are not yet adequately represented in the existing matrix of conservation lands. The Gap Analysis Program (GAP) is sponsored by the Biological Resources Discipline of the U.S. Geological Survey (USGS). The Ohio Aquatic GAP (OH-GAP) is a pilot project that is applying the GAP concept to aquatic-specifically, riverine-data. The mission of GAP is to provide regional assessments of the conservation status of native animal species and to facilitate the application of this information to land-management activities. OH-GAP accomplished this through * mapping aquatic habitat types, * mapping the predicted distributions of fish, crayfish, and bivalves, * documenting the presence of aquatic species in areas managed for conservation, * providing GAP results to the public, planners, managers, policy makers, and researchers, and * building cooperation with multiple organizations to apply GAP results to state and regional management activities. Gap analysis is a coarse-scale assessment of aquatic biodiversity and conservation; the goal is to identify gaps in the conservation of native aquatic species. It is not a substitute for biological field studies and monitoring programs. Gap analysis was conducted for the continuously flowing streams in Ohio. Lakes, reservoirs, wetlands, and the Lake Erie islands were not included in this analysis. The streams in Ohio are in the Lake Erie and Ohio River watersheds and pass through six of the level III ecoregions defined by Omernik: the Eastern Corn Belt Plains, Southern Michigan/Northern Indiana Drift Plains, Huron/Erie Lake Plain, Erie Drift Plains, Interior Plateau, and the Western Allegheny Plateau. To characterize the aquatic habitats available to Ohio fish, crayfish, and bivalves, a classification system needed to be developed and mapped. The process of classification includes delineation of areas of relative

  16. Ecological niche transferability using invasive species as a case study.

    Directory of Open Access Journals (Sweden)

    Miguel Fernández

    Full Text Available Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range.

  17. Global phylogenetics of Diuraphis noxia (Hemiptera: Aphididae), an invasive aphid species: Evidence for multiple invasions into North America

    Science.gov (United States)

    Critical to the study of an invasive species is understanding the number and origin of invasions that have occurred, as well as the rate or potential of post-invasion adaptation and geographic range expansion. One virulent, invasive insect species that has caused much damage in the United States is...

  18. Essential elements of online information networks on invasive alien species

    Science.gov (United States)

    Simpson, A.; Sellers, E.; Grosse, A.; Xie, Y.

    2006-01-01

    In order to be effective, information must be placed in the proper context and organized in a manner that is logical and (preferably) standardized. Recently, invasive alien species (IAS) scientists have begun to create online networks to share their information concerning IAS prevention and control. At a special networking session at the Beijing International Symposium on Biological Invasions, an online Eastern Asia-North American IAS Information Network (EA-NA Network) was proposed. To prepare for the development of this network, and to provide models for other regional collaborations, we compare four examples of global, regional, and national online IAS information networks: the Global Invasive Species Information Network, the Invasives Information Network of the Inter-American Biodiversity Information Network, the Chinese Species Information System, and the Invasive Species Information Node of the US National Biological Information Infrastructure. We conclude that IAS networks require a common goal, dedicated leaders, effective communication, and broad endorsement, in order to obtain sustainable, long-term funding and long-term stability. They need to start small, use the experience of other networks, partner with others, and showcase benefits. Global integration and synergy among invasive species networks will succeed with contributions from both the top-down and the bottom-up. ?? 2006 Springer.

  19. Species diversity reduces invasion success in pathogen-regulated communities

    OpenAIRE

    Turnbull, L. A.; Levine, J.M.; Fergus, A J F; Petermann, J.S.

    2010-01-01

    The loss of natural enemies is thought to explain why certain invasive species are so spectacularly successful in their introduced range. However, if losing natural enemies leads to unregulated population growth, this implies that native species are themselves normally subject to natural enemy regulation. One possible widespread mechanism of natural enemy regulation is negative soil feedbacks, in which resident species growing on home soils are disadvantaged because of a build-up of species-s...

  20. Beyond climate: disturbance niche shifts in invasive species

    OpenAIRE

    González-Moreno, Pablo; Diez, Jeffrey M.; Richardson, David M.; Vilà, Montserrat

    2015-01-01

    Analysing how species niches shift between native and introduced ranges is a powerful tool for understanding the determinants of species distributions and for anticipating range expansions by invasive species. Most studies only consider the climatic niche, by correlating widely available presence-only data with regional climate. However, habitat characteristics and disturbance also shape species niches, thereby potentially confounding shifts attributed only to differences in climate. Here we ...

  1. Camas - Invasive Species Management with Refuge Volunteers

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In the past Camas NWR has focused on mapping and treating only Russian knapweed and swainsonpea. We have other species present in lower numbers and quite possibly...

  2. Invasive Species - A Threat to the Homeland?

    Science.gov (United States)

    2003-04-07

    species of weeds, diseases and organisms on both my farm and the surrounding woodlands. Some of these species include soybean cyst nematode , soybean aphid...many of the chemicals used to control unwanted plants and even make them resistant to some natural biologic insect controls – thereby making the...such as fencing), and release of biological control agents, pesticides, and cultural practices. In addition, Executive Order 13112 requires

  3. Implementing invasive species management in an adaptive management framework

    Directory of Open Access Journals (Sweden)

    Llewellyn C. Foxcroft

    2011-05-01

    Full Text Available Adaptive management theory has attracted substantial interest in recent years, in natural resource management in general and also for invasive alien species management. However, whilst many theoretical and conceptual advances have been made, documented cases of practical applications are rare. Coupling invasive species management components with adaptive feedback processes is not without challenges, requiring a substantial change in the thinking and practice of all those involved. Drawing on a decade of experience in South African National Parks, we suggest an approach to implementing adaptive management for controlling invasive alien species. Whilst efforts have been made to advance components of the overall management strategy, the absence of a framework for decision making and feedback mechanisms, inflexibility in the system and shortcomings in the governance structure are all identified as barriers to learning and knowledge integration for the purposes of effective invasive alien species management. The framework provided here, encompassing documents, committees and processes, is aimed at addressing these shortcomings.Conservation implication: Adaptive management theory offers a robust tool for managing inherently complex systems. Its practical application, however, requires distilling the theory into useable functions. We offer a framework to advance implementation of strategic adaptive management for the control of invasive alien species using experiences gained from South African National Parks.

  4. Invasive Species Guidebook for Department of Defense Installations in the Delaware River Basin: Identification, Control, and Restoration

    Science.gov (United States)

    2009-06-01

    wildflowers and their related organisms. Fig buttercup’s early growth period allows it to become well established before native spring plants begin...pest of waterways from coastal Virginia to Florida and west to Texas, with a disjunct population in California . It exhibits both aquatic and...University of California -Davis database, and Washington State Department of Ecology. 112 INVASIVE SPECIES GUIDEBOOK FOR DOD INSTALLATIONS IN THE DELAWARE

  5. Phenotypic plasticity of selected species of aquatic insects

    OpenAIRE

    Dudová, Pavla

    2014-01-01

    Phenotypic plasticity is the ability of the single genotype to pruduce multiple phenotypes in response to evironmental conditions. There are many factors affecting phenotypic plasticity. The aim of this thesis is to summarize the current knowledge of phenotypic plasticity of aquatic insects with emphasis on the role of temperature and food availability. The review is complemented by a laboratory experiments designed to investigate the effect of temperature and food availability on growth and ...

  6. Nitrogen and protein contents in some aquatic plant species

    OpenAIRE

    Krystyna Bytniewska

    2015-01-01

    Nitrogen and protein contents in higher aquatic plants deriving from a natural habitat were determined. The following plants were examined: Spirodela polyrrhiza (L.) Schleid., Elodea canadensis Rich., Riccia fluitans L. Total nitrogen and nitrogen of respective fractions were determined by the Kjeldahl method. Nitrogen compounds were fractionated according to Thimann et al. Protein was extracted after Fletcher and Osborne and fractionated after Osborne. It was found, that total protein conten...

  7. Emergence and accumulation of novel pathogens suppress an invasive species.

    Science.gov (United States)

    Stricker, Kerry Bohl; Harmon, Philip F; Goss, Erica M; Clay, Keith; Luke Flory, S

    2016-04-01

    Emerging pathogens are a growing threat to human health, agriculture and the diversity of ecological communities but may also help control problematic species. Here we investigated the diversity, distribution and consequences of emerging fungal pathogens infecting an aggressive invasive grass that is rapidly colonising habitats throughout the eastern USA. We document the recent emergence and accumulation over time of diverse pathogens that are members of a single fungal genus and represent multiple, recently described or undescribed species. We also show that experimental suppression of these pathogens increased host performance in the field, demonstrating the negative effects of emerging pathogens on invasive plants. Our results suggest that invasive species can facilitate pathogen emergence and amplification, raising concerns about movement of pathogens among agricultural, horticultural, and wild grasses. However, one possible benefit of pathogen accumulation is suppression of aggressive invaders over the long term, potentially abating their negative impacts on native communities.

  8. A perceived gap between invasive species research and stakeholder priorities

    Directory of Open Access Journals (Sweden)

    Helen Bayliss

    2013-10-01

    Full Text Available Information from research has an important role to play in shaping policy and management responses to biological invasions but concern has been raised that research focuses more on furthering knowledge than on delivering practical solutions. We collated 449 priority areas for science and management from 160 stakeholders including practitioners, researchers and policy makers or advisors working with invasive species, and then compared them to the topics of 789 papers published in eight journals over the same time period (2009–2010. Whilst research papers addressed most of the priority areas identified by stakeholders, there was a difference in geographic and biological scales between the two, with individual studies addressing multiple priority areas but focusing on specific species and locations. We hypothesise that this difference in focal scales, combined with a lack of literature relating directly to management, contributes to the perception that invasive species research is not sufficiently geared towards delivering practical solutions. By emphasising the practical applications of applied research, and ensuring that pure research is translated or synthesised so that the implications are better understood, both the management of invasive species and the theoretical science of invasion biology can be enhanced.

  9. Utilization of two invasive free-floating aquatic plants (Pistia stratiotes and Eichhornia crassipes) as sorbents for oil removal.

    Science.gov (United States)

    Yang, Xunan; Chen, Shanshan; Zhang, Renduo

    2014-01-01

    Free-floating aquatic plants Pistia stratiotes and Eichhornia crassipes are well-known invasive species in the tropics and subtropics. The aim of this study was to utilize the plants as cost-effective and environmentally friendly oil sorbents. Multilevel wrinkle structure of P. stratiotes leaf (PL), rough surface of E. crassipes leaf (EL), and box structure of E. crassipes stalk (ES) were observed using the scanning electron microscope. The natural hydrophobic structures and capillary rise tests supported the idea to use P. stratiotes and E. crassipes as oil sorbents. Experiments indicated that the oil sorption by the plants was a fast process. The maximum sorption capacities for different oils reached 5.1-7.6, 3.1-4.8, and 10.6-11.7 g of oil per gram of sorbent for PL, EL, and ES, respectively. In the range of 5-35 °C, the sorption capacities of the plants were not significantly different. These results suggest that the plants can be used as efficient oil sorbents.

  10. Allelopathic Effects of Invasive Woody Plant Species in Hungary

    Directory of Open Access Journals (Sweden)

    CSISZÁR, Ágnes

    2009-01-01

    Full Text Available Allelopathy may play an important role in the invasion success of adventive plant species.The aim of this study was to determine the allelopathic potential of invasive woody plant species occurringin Hungary. Juglone index of fourteen invasive woody plant species in Hungary was determined by themethod of Szabó (1997, comparing the effects of juglone and substance extracted of plant species withunknown allelopathic potential on the germination rate, shoot length and rooth length of white mustard(Sinapis alba L. used as receiver species. Results have proven a more or less expressed allelopathicpotential in case of all species. The juglone index at higher concentration extracts (5 g dry plant materialextracted with 100 ml distilled water of almost every studied species approaches to 1 or is above 1, thismeans the effect of the extracts is similar to juglone or surpasses it. In terms of juglone index, theallelopathic potential of false indigo (Amorpha fruticosa L., tree-of-heaven (Ailanthus altissima (Mill.Swingle and hackberry (Celtis occidentalis L. were the highest. Besides these species the treatment withthe extracts of black walnut (Juglans nigra L., black cherry (Prunus serotina Ehrh. and green ash(Fraxinus pennsylvanica MARSH. var. subintegerrima (Vahl Fern. reduced extremely significantly thegermination rate, shoot and root length, compared to the control.

  11. Fishes and other aquatic species in the Byzantine literature. Classification, terminology and scientific names.

    Directory of Open Access Journals (Sweden)

    Maria CHRONE-VAKALOPOULOS

    2009-01-01

    Full Text Available Fishes and other aquatic species were substantial food in the every day life of Byzantine people. The predomination of Christianity contributed to the increased consumption of fishes and other seafood compared to the meat of land animals and chicken. More than a hundred ten names of fishes and about thirty names of other aquatic organisms are found in the sources of the Byzantine literature. Most frequent references are found in the medical texts of the Byzantine doctors, where, fishes are classified in categories depending on their physiology and origin, because, according to the writers, these are determining factors for the evaluation of the nutritional value of each species.The purpose of this study is to present the terminology of the fishes and the various aquatic species that are found in the Byzantine sources and to identify, in parallel, each species with its current scientific name.  

  12. Nitrogen and protein contents in some aquatic plant species

    Directory of Open Access Journals (Sweden)

    Krystyna Bytniewska

    2015-01-01

    Full Text Available Nitrogen and protein contents in higher aquatic plants deriving from a natural habitat were determined. The following plants were examined: Spirodela polyrrhiza (L. Schleid., Elodea canadensis Rich., Riccia fluitans L. Total nitrogen and nitrogen of respective fractions were determined by the Kjeldahl method. Nitrogen compounds were fractionated according to Thimann et al. Protein was extracted after Fletcher and Osborne and fractionated after Osborne. It was found, that total protein content in the plants under examination constitutes 18 to 25%o of dry matter. Albumins and glutelins are the most abundant protein fractions.

  13. Insect Eradication and Containment of Invasive Alien Species

    Science.gov (United States)

    Insect eradication programs are nearly always targeted at recently arrived invasive species with significant pest potential. They attempt to contain a pest to a defined area and then completely eliminate the pest from that area. From a Federal regulatory standpoint, eradication programs are undert...

  14. Historic land use influences contemporary establishment of invasive plant species.

    Science.gov (United States)

    Mattingly, W Brett; Orrock, John L

    2013-08-01

    The legacy of agricultural land use can have widespread and persistent effects on contemporary landscapes. Although agriculture can lead to persistent changes in soil characteristics and plant communities, it remains unclear whether historic agricultural land use can alter the likelihood of contemporary biological invasions. To understand how agricultural land-use history might interact with well-known drivers of invasion, we conducted factorial manipulations of soil disturbance and resource additions within non-agricultural remnant sites and post-agricultural sites invaded by two non-native Lespedeza species. Our results reveal that variation in invader success can depend on the interplay of historic land use and contemporary processes: for both Lespedeza species, establishment was greater in remnant sites, but soil disturbance enhanced establishment irrespective of land-use history, demonstrating that contemporary processes can help to overcome legacy constraints on invader success. In contrast, additions of resources known to facilitate seedling recruitment (N and water) reduced invader establishment in post-agricultural but not in remnant sites, providing evidence that interactions between historic and contemporary processes can also limit invader success. Our findings thus illustrate that a consideration of historic land use may help to clarify the often contingent responses of invasive plants to known determinants of invasibility. Moreover, in finding significantly greater soil compaction at post-agricultural sites, our study provides a putative mechanism for historic land-use effects on contemporary invasive plant establishment. Our work suggests that an understanding of invasion dynamics requires knowledge of anthropogenic events that often occur decades before the introduction of invasive propagules.

  15. Incentivizing the public to support invasive species management: eurasian milfoil reduces lakefront property values.

    Directory of Open Access Journals (Sweden)

    Julian D Olden

    Full Text Available Economic evaluations of invasive species are essential for providing comprehensive assessments of the benefits and costs of publicly-funded management activities, yet many previous investigations have focused narrowly on expenditures to control spread and infestation. We use hedonic modeling to evaluate the economic effects of Eurasian milfoil (Myriophyllum spicatum invasions on lakefront property values of single-family homes in an urban-suburban landscape. Milfoil often forms dense canopies at the water surface, diminishing the value of ecosystem services (e.g., recreation, fishing and necessitating expensive control and management efforts. We compare 1,258 lakeshore property sale transactions (1995-2006 in 17 lakes with milfoil and 24 un-invaded lakes in King County, Washington (USA. After accounting for structural (e.g., house size, locational (e.g., boat launch, and environmental characteristics (e.g., water clarity of lakes, we found that milfoil has a significant negative effect on property sales price ($94,385 USD lower price, corresponding to a 19% decline in mean property values. The aggregate cost of milfoil invading one additional lake in the study area is, on average, $377,542 USD per year. Our study illustrates that invasive aquatic plants can significantly impact property values (and associated losses in property taxes that reduce local government revenue, justifying the need for management strategies that prevent and control invasions. We recommend coordinated efforts across Lake Management Districts to focus institutional support, funding, and outreach to prevent the introduction and spread of milfoil. This effort will limit opportunities for re-introduction from neighboring lakes and incentivize private landowners and natural resource agencies to commit time and funding to invasive species management.

  16. Assessment of in silico methods to estimate aquatic species sensitivity

    Science.gov (United States)

    Determining the sensitivity of a diversity of species to environmental contaminants continues to be a significant challenge in ecological risk assessment because toxicity data are generally limited to a few standard species. In many cases, QSAR models are used to estimate toxici...

  17. Comprehensive review on phytotechnology: Heavy metals removal by diverse aquatic plants species from wastewater.

    Science.gov (United States)

    Rezania, Shahabaldin; Taib, Shazwin Mat; Md Din, Mohd Fadhil; Dahalan, Farrah Aini; Kamyab, Hesam

    2016-11-15

    Environmental pollution specifically water pollution is alarming both in the developed and developing countries. Heavy metal contamination of water resources is a critical issue which adversely affects humans, plants and animals. Phytoremediation is a cost-effective remediation technology which able to treat heavy metal polluted sites. This environmental friendly method has been successfully implemented in constructed wetland (CWs) which is able to restore the aquatic biosystem naturally. Nowadays, many aquatic plant species are being investigated to determine their potential and effectiveness for phytoremediation application, especially high growth rate plants i.e. macrophytes. Based on the findings, phytofiltration (rhizofiltration) is the sole method which defined as heavy metals removal from water by aquatic plants. Due to specific morphology and higher growth rate, free-floating plants were more efficient to uptake heavy metals in comparison with submerged and emergent plants. In this review, the potential of wide range of aquatic plant species with main focus on four well known species (hyper-accumulators): Pistia stratiotes, Eicchornia spp., Lemna spp. and Salvinia spp. was investigated. Moreover, we discussed about the history, methods and future prospects in phytoremediation of heavy metals by aquatic plants comprehensively.

  18. Seed bank survival of an invasive species, but not of two native species, declines with invasion.

    Science.gov (United States)

    Orrock, John L; Christopher, Cory C; Dutra, Humberto P

    2012-04-01

    Soil-borne seed pathogens may play an important role in either hindering or facilitating the spread of invasive exotic plants. We examined whether the invasive shrub Lonicera maackii (Caprifoliaceae) affected fungi-mediated mortality of conspecific and native shrub seeds in a deciduous forest in eastern Missouri. Using a combination of L. maackii removal and fungicide treatments, we found no effect of L. maackii invasion on seed viability of the native Symphoricarpos orbiculatus (Caprifoliaceae) or Cornus drummondii (Cornaceae). In contrast, fungi were significant agents of L. maackii seed mortality in invaded habitats. Losses of L. maackii to soil fungi were also significant in invaded habitats where L. maackii had been removed, although the magnitude of the effect of fungi was lower, suggesting that changes in soil chemistry or microhabitat caused by L. maackii were responsible for affecting fungal seed pathogens. Our work suggests that apparent competition via soil pathogens is not an important factor contributing to impacts of L. maackii on native shrubs. Rather, we found that fungal seed pathogens have density-dependent effects on L. maackii seed survival. Therefore, while fungal pathogens may provide little biotic resistance to early invasion by L. maackii, our study illustrates that more work is needed to understand how changes in fungal pathogens during the course of an invasion contribute to the potential for restoration of invaded systems. More generally, our study suggests that increased rates of fungal pathogen attack may be realized by invasive plants, such as L. maackii, that change the chemical or physical environment of the habitats they invade.

  19. Conservation planning for imperiled aquatic species in an urbanizing environment

    Science.gov (United States)

    Wenger, Seth J.; Freeman, Mary C.; Fowler, Laurie A.; Freeman, Byron J.; Peterson, James T.

    2010-01-01

    As the global area devoted to urban uses grows, an increasing number of freshwater species will face imperilment due to urbanization effects. Management of these impacts on both private and public lands is necessary to ensure species persistence. Such management entails several hallenges: (1) development of a management policy appropriate to the stressors; (2) linking stressor levels to species population attributes; (3) forecasting the effects of alternative management policy decisions on the species, and (4) using adaptive management to adjust the policy in the future. We illustrate how these challenges were addressed under the Etowah Habitat Conservation Plan (Etowah HCP), a management plan for three federally protected fish species in Georgia, USA. The plan involved the creation of a management policy to address the impacts of the greatest stressor, stormwater runoff, as well as other stressors. Models were constructed to link population indices of the three species with a key indicator of stormwater runoff, effective impervious area (EIA). Then, models were applied to projected levels of EIA under full watershed buildout to fine-tune the parameters of the management policy. Forecasting indicated that the most sensitive species, the Etowah darter, was likely to decline by 84% in the absence of the Etowah HCP, but only 23% if the Etowah HCP were implemented. Although there was substantial uncertainty in model predictions, an adaptive management plan was established to incorporate new data and to adjust management policies as necessary.

  20. Calibrating snakehead diversity with DNA barcodes: expanding taxonomic coverage to enable identification of potential and established invasive species.

    Directory of Open Access Journals (Sweden)

    Natasha R Serrao

    Full Text Available Detecting and documenting the occurrence of invasive species outside their native range requires tools to support their identification. This can be challenging for taxa with diverse life stages and/or problematic or unresolved morphological taxonomies. DNA barcoding provides a potent method for identifying invasive species, as it allows for species identification at all life stages, including fragmentary remains. It also provides an efficient interim taxonomic framework for quantifying cryptic genetic diversity by parsing barcode sequences into discontinuous haplogroup clusters (typical of reproductively isolated species and labelling them with unique alphanumeric identifiers. Snakehead fishes are a diverse group of opportunistic predators endemic to Asia and Africa that may potentially pose significant threats as aquatic invasive species. At least three snakehead species (Channa argus, C. maculata, and C. marulius are thought to have entered North America through the aquarium and live-food fish markets, and have established populations, yet their origins remain unclear. The objectives of this study were to assemble a library of DNA barcode sequences derived from expert identified reference specimens in order to determine the identity and aid invasion pathway analysis of the non-indigenous species found in North America using DNA barcodes. Sequences were obtained from 121 tissue samples representing 25 species and combined with public records from GenBank for a total of 36 putative species, which then partitioned into 49 discrete haplogroups. Multiple divergent clusters were observed within C. gachua, C. marulius, C. punctata and C. striata suggesting the potential presence of cryptic species diversity within these lineages. Our findings demonstrate that DNA barcoding is a valuable tool for species identification in challenging and under-studied taxonomic groups such as snakeheads, and provides a useful framework for inferring invasion pathway

  1. Calibrating snakehead diversity with DNA barcodes: expanding taxonomic coverage to enable identification of potential and established invasive species.

    Science.gov (United States)

    Serrao, Natasha R; Steinke, Dirk; Hanner, Robert H

    2014-01-01

    Detecting and documenting the occurrence of invasive species outside their native range requires tools to support their identification. This can be challenging for taxa with diverse life stages and/or problematic or unresolved morphological taxonomies. DNA barcoding provides a potent method for identifying invasive species, as it allows for species identification at all life stages, including fragmentary remains. It also provides an efficient interim taxonomic framework for quantifying cryptic genetic diversity by parsing barcode sequences into discontinuous haplogroup clusters (typical of reproductively isolated species) and labelling them with unique alphanumeric identifiers. Snakehead fishes are a diverse group of opportunistic predators endemic to Asia and Africa that may potentially pose significant threats as aquatic invasive species. At least three snakehead species (Channa argus, C. maculata, and C. marulius) are thought to have entered North America through the aquarium and live-food fish markets, and have established populations, yet their origins remain unclear. The objectives of this study were to assemble a library of DNA barcode sequences derived from expert identified reference specimens in order to determine the identity and aid invasion pathway analysis of the non-indigenous species found in North America using DNA barcodes. Sequences were obtained from 121 tissue samples representing 25 species and combined with public records from GenBank for a total of 36 putative species, which then partitioned into 49 discrete haplogroups. Multiple divergent clusters were observed within C. gachua, C. marulius, C. punctata and C. striata suggesting the potential presence of cryptic species diversity within these lineages. Our findings demonstrate that DNA barcoding is a valuable tool for species identification in challenging and under-studied taxonomic groups such as snakeheads, and provides a useful framework for inferring invasion pathway analysis.

  2. Mapping of riparian invasive species with supervised classification of Unmanned Aerial System (UAS) imagery

    Science.gov (United States)

    Michez, Adrien; Piégay, Hervé; Jonathan, Lisein; Claessens, Hugues; Lejeune, Philippe

    2016-02-01

    Riparian zones are key landscape features, representing the interface between terrestrial and aquatic ecosystems. Although they have been influenced by human activities for centuries, their degradation has increased during the 20th century. Concomitant with (or as consequences of) these disturbances, the invasion of exotic species has increased throughout the world's riparian zones. In our study, we propose a easily reproducible methodological framework to map three riparian invasive taxa using Unmanned Aerial Systems (UAS) imagery: Impatiens glandulifera Royle, Heracleum mantegazzianum Sommier and Levier, and Japanese knotweed (Fallopia sachalinensis (F. Schmidt Petrop.), Fallopia japonica (Houtt.) and hybrids). Based on visible and near-infrared UAS orthophoto, we derived simple spectral and texture image metrics computed at various scales of image segmentation (10, 30, 45, 60 using eCognition software). Supervised classification based on the random forests algorithm was used to identify the most relevant variable (or combination of variables) derived from UAS imagery for mapping riparian invasive plant species. The models were built using 20% of the dataset, the rest of the dataset being used as a test set (80%). Except for H. mantegazzianum, the best results in terms of global accuracy were achieved with the finest scale of analysis (segmentation scale parameter = 10). The best values of overall accuracies reached 72%, 68%, and 97% for I. glandulifera, Japanese knotweed, and H. mantegazzianum respectively. In terms of selected metrics, simple spectral metrics (layer mean/camera brightness) were the most used. Our results also confirm the added value of texture metrics (GLCM derivatives) for mapping riparian invasive species. The results obtained for I. glandulifera and Japanese knotweed do not reach sufficient accuracies for operational applications. However, the results achieved for H. mantegazzianum are encouraging. The high accuracies values combined to

  3. 'Caribbean Creep' chills out: climate change and marine invasive species.

    Directory of Open Access Journals (Sweden)

    João Canning-Clode

    Full Text Available BACKGROUND: New marine invasions have been recorded in increasing numbers along the world's coasts due in part to the warming of the oceans and the ability of many invasive marine species to tolerate a broader thermal range than native species. Several marine invertebrate species have invaded the U.S. southern and mid-Atlantic coast from the Caribbean and this poleward range expansion has been termed 'Caribbean Creep'. While models have predicted the continued decline of global biodiversity over the next 100 years due to global climate change, few studies have examined the episodic impacts of prolonged cold events that could impact species range expansions. METHODOLOGY/PRINCIPAL FINDINGS: A pronounced cold spell occurred in January 2010 in the U.S. southern and mid-Atlantic coast and resulted in the mortality of several terrestrial and marine species. To experimentally test whether cold-water temperatures may have caused the disappearance of one species of the 'Caribbean Creep' we exposed the non-native crab Petrolisthes armatus to different thermal treatments that mimicked abnormal and severe winter temperatures. Our findings indicate that Petrolisthes armatus cannot tolerate prolonged and extreme cold temperatures (4-6 °C and suggest that aperiodic cold winters may be a critical 'reset' mechanism that will limit the range expansion of other 'Caribbean Creep' species. CONCLUSIONS/SIGNIFICANCE: We suggest that temperature 'aberrations' such as 'cold snaps' are an important and overlooked part of climate change. These climate fluctuations should be accounted for in future studies and models, particularly with reference to introduced subtropical and tropical species and predictions of both rates of invasion and rates of unidirectional geographic expansion.

  4. Species pools, community completeness and invasion: disentangling diversity effects on the establishment of native and alien species.

    Science.gov (United States)

    Bennett, Jonathan A; Riibak, Kersti; Kook, Ene; Reier, Ülle; Tamme, Riin; Guillermo Bueno, C; Pärtel, Meelis

    2016-12-01

    Invasion should decline with species richness, yet the relationship is inconsistent. Species richness, however, is a product of species pool size and biotic filtering. Invasion may increase with richness if large species pools represent weaker environmental filters. Measuring species pool size and the proportion realised locally (completeness) may clarify diversity-invasion relationships by separating environmental and biotic effects, especially if species' life-history stage and origin are accounted for. To test these relationships, we added seeds and transplants of 15 native and alien species into 29 grasslands. Species pool size and completeness explained more variation in invasion than richness alone. Although results varied between native and alien species, seed establishment and biotic resistance to transplants increased with species pool size, whereas transplant growth and biotic resistance to seeds increased with completeness. Consequently, species pools and completeness represent multiple independent processes affecting invasion; accounting for these processes improves our understanding of invasion.

  5. Abstracts of Presentation: Aquatic Species Program Annual Review Meeting, Golden, Colorado, 24-25 September 1986

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    The goal of the aquatic species program is to produce gasoline and diesel fuels from microalgae grown in saline waters of the desert southwest. Microalgae are known to accumulate lipids in large quantities and can thrive in high salinity water which currently has no other use.

  6. 75 FR 53273 - Federal Aquatic Nuisance Species Research Risk Analysis Protocol

    Science.gov (United States)

    2010-08-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE... aquatic nuisance species, which shall be administered through the National Sea Grant College Program and... comments and make revisions, as appropriate, to the Protocol before going final. You may submit a...

  7. Control of Invasive Species: Lessons from Miconia in Hawaii

    OpenAIRE

    Brooks Kaiser; Kimberly Burnett; James Roumasset

    2006-01-01

    Once established, invasive species can rapidly and irreversibly alter ecosystems and degrade the value of ecosystem services. Optimal control of an exotic pest solves for a trajectory of removals that minimizes the present value of removal costs and residual damages from the remaining pest population. The shrubby tree, Miconia calvescens, is used to illustrate dynamic policy options for a forest invader. Potential damages to Hawaii's forest ecosystems are related to decreased aquifer recharge...

  8. Tualatin River - Urban Refuge Combating Invasive Species through Learning and Participating

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This grant is 2 pronged with a strong focus on invasive species outreach and education and a supporting focus on active field management of native/invasive species....

  9. A 3D individual-based aquatic transport model for the assessment of the potential dispersal of planktonic larvae of an invasive bivalve.

    Science.gov (United States)

    Hoyer, Andrea B; Wittmann, Marion E; Chandra, Sudeep; Schladow, S Geoffrey; Rueda, Francisco J

    2014-12-01

    The unwanted impacts of non-indigenous species have become one of the major ecological and economic threats to aquatic ecosystems worldwide. Assessing the potential dispersal and colonization of non-indigenous species is necessary to prevent or reduce deleterious effects that may lead to ecosystem degradation and a range of economic impacts. A three dimensional (3D) numerical model has been developed to evaluate the local dispersal of the planktonic larvae of an invasive bivalve, Asian clam (Corbicula fluminea), by passive hydraulic transport in Lake Tahoe, USA. The probability of dispersal of Asian clam larvae from the existing high density populations to novel habitats is determined by the magnitude and timing of strong wind events. The probability of colonization of new near-shore areas outside the existing beds is low, but sensitive to the larvae settling velocity ws. High larvae mortality was observed due to settling in unsuitable deep habitats. The impact of UV-radiation during the pelagic stages, on the Asian clam mortality was low. This work provides a quantification of the number of propagules that may be successfully transported as a result of natural processes and in function of population size. The knowledge and understanding of the relative contribution of different dispersal pathways, may directly inform decision-making and resource allocation associated with invasive species management.

  10. Do low oxygen environments facilitate marine invasions? Relative tolerance of native and invasive species to low oxygen conditions.

    Science.gov (United States)

    Lagos, Marcelo E; Barneche, Diego R; White, Craig R; Marshall, Dustin J

    2017-02-17

    Biological invasions are one of the biggest threats to global biodiversity. Marine artificial structures are proliferating worldwide and provide a haven for marine invasive species. Such structures disrupt local hydrodynamics, which can lead to the formation of oxygen-depleted microsites. The extent to which native fauna can cope with such low oxygen conditions, and whether invasive species, long associated with artificial structures in flow-restricted habitats, have adapted to these conditions remains unclear. We measured water flow and oxygen availability in marinas and piers at the scales relevant to sessile marine invertebrates (mm). We then measured the capacity of invasive and native marine invertebrates to maintain metabolic rates under decreasing levels of oxygen using standard laboratory assays. We found that marinas reduce water flow relative to piers, and that local oxygen levels can be zero in low flow conditions. We also found that for species with erect growth forms, invasive species can tolerate much lower levels of oxygen relative to native species. Integrating the field and laboratory data showed that up to 30% of available microhabitats within low flow environments are physiologically stressful for native species, while only 18% of the same habitat is physiologically stressful for invasive species. These results suggest that invasive species have adapted to low oxygen habitats associated with manmade habitats, and artificial structures may be creating niche opportunities for invasive species.

  11. Bartonella species in invasive rats and indigenous rodents from Uganda.

    Science.gov (United States)

    Billeter, Sarah A; Borchert, Jeff N; Atiku, Linda A; Mpanga, Joseph T; Gage, Kenneth L; Kosoy, Michael Y

    2014-03-01

    The presence of bartonellae in invasive rats (Rattus rattus) and indigenous rodents (Arvicanthis niloticus and Cricetomys gambianus) from two districts in Uganda, Arua and Zombo, was examined by PCR detection and culture. Blood from a total of 228 R. rattus, 31 A. niloticus, and 5 C. gambianus was screened using genus-specific primers targeting the 16S-23S intergenic spacer region. Furthermore, rodent blood was plated on brain heart infusion blood agar, and isolates were verified as Bartonella species using citrate synthase gene- (gltA) specific primers. One hundred and four fleas recovered from R. rattus were also tested for the presence of Bartonella species using the same gltA primer set. An overall prevalence of 1.3% (three of 228) was obtained in R. rattus, whereas 61.3% of 31 A. niloticus and 60% of five C. gambianus were positive for the presence of Bartonella species. Genotypes related to Bartonella elizabethae, a known zoonotic pathogen, were detected in three R. rattus and one C. gambianus. Bartonella strains, similar to bacteria detected in indigenous rodents from other African countries, were isolated from the blood of A. niloticus. Bartonellae, similar to bacteria initially cultured from Ornithodorus sonrai (soft tick) from Senegal, were found in two C. gambianus. Interestingly, bartonellae detected in fleas from invasive rats were similar to bacteria identified in indigenous rodents and not their rat hosts, with an overall prevalence of 6.7%. These results suggest that if fleas are competent vectors of these bartonellae, humans residing in these two districts of Uganda are potentially at greater risk for exposure to Bartonella species from native rodents than from invasive rats. The low prevalence of bartonellae in R. rattus was quite surprising, in contrast, to the detection of these organisms in a large percentage of Rattus species from other geographical areas. A possible reason for this disparity is discussed.

  12. Effects of invasive European bird cherry (Prunus padus) on leaf litter processing by aquatic invertebrate shredder communities in urban Alaskan streams

    Science.gov (United States)

    Roon, David A.; Wipfli, Mark S.; Wurtz, Tricia L.

    2014-01-01

    European bird cherry (Prunus padus) (EBC) is an invasive ornamental tree that is spreading rapidly in riparian forests of urban Alaska. To determine how the spread of EBC affects leaf litter processing by aquatic invertebrate shredders, we conducted complementary leaf pack experiments in two streams located in Anchorage, Alaska. The first experiment contrasted invasive EBC with three native tree species—thin-leaf alder (Alnus tenuifolia), paper birch (Betula neoalaskana), and black cottonwood (Populus trichocarpa)—in one reach of Chester Creek; finding that EBC leaf litter broke down significantly faster than birch and cottonwood, but at a similar rate to alder. The second experiment contrasted EBC with alder in four reaches of Campbell and Chester creeks; finding that while EBC leaf litter broke down significantly faster than alder in Chester Creek, EBC broke down at a similar rate to alder in Campbell Creek. Although EBC sometimes supported fewer shredders by both count and mass, shredder communities did not differ significantly between EBC and native plants. Collectively, these data suggest that invasive EBC is not currently exhibiting strong negative impacts on leaf litter processing in these streams, but could if it continues to spread and further displaces native species over time.

  13. Mycorrhizal status helps explain invasion success of alien plant species.

    Science.gov (United States)

    Menzel, Andreas; Hempel, Stefan; Klotz, Stefan; Moora, Mari; Pyšek, Petr; Rillig, Matthias C; Zobel, Martin; Kühn, Ingolf

    2017-01-01

    It is still debated whether alien plants benefit from being mycorrhizal, or if engaging in the symbiosis constrains their establishment and spread in new regions. We analyzed the association between mycorrhizal status of alien plant species in Germany and their invasion success. We compared whether the representation of species with different mycorrhizal status (obligate, facultative, or non-mycorrhizal) differed at several stages of the invasion process. We used generalized linear models to explain the occupied geographical range of alien plants, incorporating interactions of mycorrhizal status with plant traits related to morphology, reproduction, and life-history. Non-naturalized aliens did not differ from naturalized aliens in the relative frequency of different mycorrhizal status categories. Mycorrhizal status significantly explained the occupied range of alien plants; with facultative mycorrhizal species inhabiting a larger range than non-mycorrhizal aliens and obligate mycorrhizal plant species taking an intermediate position. Aliens with storage organs, shoot metamorphoses, or specialized structures promoting vegetative dispersal occupied a larger range when being facultative mycorrhizal. We conclude that being mycorrhizal is important for the persistence of aliens in Germany and constitutes an advantage compared to being non-mycorrhizal. Being facultative mycorrhizal seems to be especially advantageous for successful spread, as the flexibility of this mycorrhizal status may enable plants to use a broader set of ecological strategies.

  14. Aquatic pollution-induced immunotoxicity in wildlife species.

    Science.gov (United States)

    Luebke, R W; Hodson, P V; Faisal, M; Ross, P S; Grasman, K A; Zelikoff, J

    1997-05-01

    The potential for chemicals to adversely affect human immunologic health has traditionally been evaluated in rodents, under laboratory conditions. These laboratory studies have generated valuable hazard identification and immunotoxicologic mechanism data; however, genetically diverse populations exposed in the wild may better reflect both human exposure conditions and may provide insight into potential immunotoxic effects in humans. In addition, comparative studies of species occupying reference and impacted sites provide important information on the effects of environmental pollution on the immunologic health of wildlife populations. In this symposium overview, Peter Hodson describes physiological changes in fish collected above or below the outflows of paper mills discharging effluent from the bleaching process (BKME). Effects attributable to BKME were identified, as were physiological changes attributable to other environmental factors. In this context, he discussed the problems of identifying true cause and effect relationships in field studies. Mohamed Faisal described changes in immune function of fish collected from areas with high levels of polyaromatic hydrocarbon contamination. His studies identified a contaminant-related decreases in the ability of anterior kidney leukocytes to bind to and kill tumor cell line targets, as well as changes in lymphocyte proliferation in response to mitogens. Altered proliferative responses of fish from the contaminated site were partially reversed by maintaining fish in water from the reference site. Peter Ross described studies in which harbor seals were fed herring obtained from relatively clean (Atlantic Ocean) and contaminated (Baltic Sea) waters. Decreased natural killer cell activity and lymphoproliferative responses to T and B cell mitogens, as well as depressed antibody and delayed hypersensitivity responses to injected antigens, were identified in seals fed contaminated herring. In laboratory studies, it was

  15. Towards Arctic Resource Governance of Marine Invasive Species

    DEFF Research Database (Denmark)

    Kourantidou, Melina; Kaiser, Brooks; Fernandez, Linda

    2015-01-01

    Scientific and policy-oriented publications highlighting the magnitude of uncertainty in the changing Arctic and the possibilities for effective regional governance are proliferating, yet it remains a challenging task to examine Arctic marine biodiversity. Limited scientific data are currently...... available. Through analysis of marine invasions in the Arctic, we work to identify and assess patterns in the knowledge gaps regarding invasive species in the Arctic that affect the ability to generate improved governance outcomes. These patterns are expected to depend on multiple aspects of scientific......, resource exploration) and indigenous communities (regarded as resource users, citizen scientists, and recipients of goods shipped from other locations). Governance gaps are examined in the context of applied national policies (such as promoting or intercepting intentional introductions), international...

  16. Interactions of gold nanoparticles with freshwater aquatic macrophytes are size and species dependent.

    Science.gov (United States)

    Glenn, J Brad; White, Sarah A; Klaine, Stephen J

    2012-01-01

    The partitioning of 4- and 18-nm gold nanoparticles (AuNPs) to aquatic macrophytes was investigated in vivo with exposure suspension in well water. Three morphologically distinct aquatic macrophytes were studied. Myriophyllum simulans Orch. and Egeria densa Planch. are submerged aquatic vascular plants, whereas Azolla caroliniana Willd. is a free-floating aquatic fern. Because aquatic plants absorb the majority of their nutrients from the water column, it is logical to hypothesize that they may absorb nanomaterials in suspension, potentially facilitating trophic transfer. Each plant was exposed to two different-sized gold nanospheres at a nominal concentration of 250 µg/L AuNPs for 24 h. Macrophytes were harvested at six time points (1, 3, 6, 12, 18, and 24 h), dried, and then analyzed for gold concentration via inductively coupled plasma-mass spectrometry. Concentrations were normalized to whole-plant dry tissue mass. The present study shows that absorption of AuNPs through root uptake was size and species dependent. Electron microscopy revealed that 4- and 18-nm AuNPs adsorbed to the roots of each species. Root tissue was sectioned, and transmission electron microscopy indicated that 4-nm and 18-nm AuNPs were absorbed by A. caroliniana, whereas only 4-nm AuNPs were absorbed by M. simulans. Egeria densa did not absorb AuNPs of either size. Gold nanoparticles were confirmed in tissue by using energy-dispersive X-ray spectroscopy. Absorption of AuNPs by plants may be a function of the salinity tolerance of each species.

  17. Aquatic species program review. Proceedings of the April 1984 principal investigators meeting

    Energy Technology Data Exchange (ETDEWEB)

    1984-05-01

    The purpose of the Aquatic Species program is to improve the productivity, conversion to fuels, and cost efficiency of aquatic plant species for energy. The emphasis of the program is on developing oil-yielding microalgae which will grow in the saline waters of the desert in the American Southwest. To meet this objective, research is carried out under three tasks: biological, engineering, and analysis. The principal objectives of the biological task are (1) to conduct a comprehensive and complete screening activity that will result in the selection of the best microalgae strains for production of fuels; (2) to establish a gene pool so that species can be improved through agronomic means; and (3) to develop techniques that will result in enhancing the yields of the desired fuel product. Engineering research is concerned with integrating biological concepts with engineering principals to develop the most cost-effective microalgal culture technology. Work is concentrated on developing culture management strategies and required subsystems such as harvesting technologies. Analysis supports the technology development through cost goal determination, resource assessment, and technology evaluation. The program also supports the development of macroalgae culture for methane gas or alcohols. This volume contains progress reports presented by the Aquatic Species Program subcontractors and SERI researchers at the SERI Biomass Program Review held in Boulder, Colorado, April 4, 1984. These reports present and discuss research advances achieved by the program participants during the preceding year. Separate abstracts have been prepared for each report for inclusion in the Energy Data Base.

  18. Species coexistence and the superior ability of an invasive species to exploit a facilitation cascade habitat.

    Science.gov (United States)

    Altieri, Andrew H; Irving, Andrew D

    2017-01-01

    Facilitation cascades generated by co-occurring foundation species can enhance the abundance and diversity of associated organisms. However, it remains poorly understood how differences among native and invasive species in their ability to exploit these positive interactions contribute to emergent patterns of community structure and biotic acceptance. On intertidal shorelines in New England, we examined the patterns of coexistence between the native mud crabs and the invasive Asian shore crab in and out of a facilitation cascade habitat generated by mid intertidal cordgrass and ribbed mussels. These crab species co-occurred in low intertidal cobbles adjacent to the cordgrass-mussel beds, despite experimental findings that the dominant mud crabs can kill and displace Asian shore crabs and thereby limit their successful recruitment to their shared habitat. A difference between the native and invasive species in their utilization of the facilitation cascade likely contributes to this pattern. Only the Asian shore crabs inhabit the cordgrass-mussel beds, despite experimental evidence that both species can similarly benefit from stress amelioration in the beds. Moreover, only Asian shore crabs settle in the beds, which function as a nursery habitat free of lethal mud crabs, and where their recruitment rates are particularly high (nearly an order of magnitude higher than outside beds). Persistence of invasive adult Asian shore crabs among the dominant native mud crabs in the low cobble zone is likely enhanced by a spillover effect of the facilitation cascade in which recruitment-limited Asian shore crabs settle in the mid intertidal cordgrass-mussel beds and subsidize their vulnerable populations in the adjacent low cobble zone. This would explain why the abundances of Asian shore crabs in cobbles are doubled when adjacent to facilitation cascade habitats. The propensity for this exotic species to utilize habitats created by facilitation cascades, despite the lack of a

  19. Evidence of qualitative differences between soil-occupancy effects of invasive vs. native grassland plant species

    Science.gov (United States)

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2011-01-01

    Diversified grasslands that contain native plant species are being recognized as important elements of agricultural landscapes and for production of biofuel feedstocks as well as a variety of other ecosystem services. Unfortunately, establishment of such grasslands is often difficult, unpredictable, and highly vulnerable to interference and invasion by weeds. Evidence suggests that soil-microbial "legacies" of invasive perennial species can inhibit growth of native grassland species. However, previous assessments of legacy effects of soil occupancy by invasive species that invade grasslands have focused on single invasive species and on responses to invasive soil occupancy in only a few species. In this study, we tested the hypothesis that legacy effects of invasive species differ qualitatively from those of native grassland species. In a glasshouse, three invasive and three native grassland perennials and a native perennial mixture were grown separately through three cycles of growth and soil conditioning in soils with and without arbuscular mycorrhizal fungi (AMF), after which we assessed seedling growth in these soils. Native species differed categorically from invasives in their response to soil conditioning by native or invasive species, but these differences depended on the presence of AMF. When AMF were present, native species largely had facilitative effects on invasive species, relative to effects of invasives on other invasives. Invasive species did not facilitate native growth; neutral effects were predominant, but strong soil-mediated inhibitory effects on certain native species occurred. Our results support the hypothesis that successful plant invaders create biological legacies in soil that inhibit native growth, but suggest also this mechanism of invasion will have nuanced effects on community dynamics, as some natives may be unaffected by such legacies. Such native species may be valuable as nurse plants that provide cost-effective restoration of

  20. Infestation of Lernaea cyprinacea (Copepoda: Lernaeidae in two invasive fish species in Romania, Lepomis gibbosus and Pseudorasbora parva

    Directory of Open Access Journals (Sweden)

    Stavrescu-Bedivan M.M.

    2014-01-01

    Full Text Available In this study we analyzed comparatively the host-parasite associations between two fish host species invasive in Europe (Lepomis gibbosus and Pseudorasbora parva and one known generalist parasite species, the copepod Lernaea cyprinacea. We used a fragment of the hypervariable region D1-D2 of the 28S rRNA to confirm that the copepod specimens collected on both host species in our study are indeed conspecific. The prevalence of infection was significantly different between the two host species in all three aquatic ecosystems. Two populations of L. gibbosus exhibited a positive correlation coefficient between the standard body length and infection intensity, while a negative correlation coefficient was observed in one population of P. parva. This is one of the few studies providing parasitological parameters of infections of Lernaea cypriancea in Lepomis gibbosus and Pseudorasbora parva.

  1. Effects of fishing technique on assessing species composition in aquatic systems in semi-arid Brazil

    Directory of Open Access Journals (Sweden)

    ESF Medeiros

    Full Text Available In most ecological field research, appropriate sampling is critical for the understanding of processes underlying fish populations and communities, and is even more important in heterogeneous environments such as the aquatic systems of the semi-arid region of Brazil. This study intends to make a contribution to the development of sampling programs and gear selection in aquatic systems of semi-arid Brazil by evaluating the effects of different fishing techniques on the assessment of richness and composition of the fish fauna in selected aquatic environments. Six sites were selected to represent typical artificial (reservoirs and natural (intermittent streams environments and four different types of sampling gear were applied to each site during four occasions. The present study shows that when selecting sampling techniques to be used in aquatic systems in semi-arid Brazil, one must consider the objectives of the study, e.g. ecological or taxonomic, in order to decide on inclusion of rare species in the sampling population. Also, the effect of the sampling gear on natural abundances of fish must be considered given that some sampling techniques are highly detrimental to fish population numbers.

  2. Biodegradation of pesticides using fungi species found in the aquatic environment.

    Science.gov (United States)

    Oliveira, B R; Penetra, A; Cardoso, V V; Benoliel, M J; Barreto Crespo, M T; Samson, R A; Pereira, V J

    2015-08-01

    Relatively limited attention has been given to the presence of fungi in the aquatic environment compared to their occurrence in other matrices. Taking advantage and recognizing the biodegradable capabilities of fungi is important, since these organisms may produce many potent enzymes capable of degrading toxic pollutants. Therefore, the aim of this study was to evaluate the potential ability of some species of filamentous fungi that occur in the aquatic environment to degrade pesticides in untreated surface water. Several laboratory-scale experiments were performed using the natural microbial population present in the aquatic environment as well as spiked fungi isolates that were found to occur in different water matrices, to test the ability of fungi to degrade several pesticides of current concern (atrazine, diuron, isoproturon and chlorfenvinphos). The results obtained in this study showed that, when spiked in sterile natural water, fungi were able to degrade chlorfenvinphos to levels below detection and unable to degrade atrazine, diuron and isoproturon. Penicillium citrinum, Aspergillus fumigatus, Aspergillus terreus and Trichoderma harzianum were found to be able to resist and degrade chlorfenvinphos. These fungi are therefore expected to play an important role in the degradation of this and other pollutants present in the aquatic environment.

  3. Two invasive acacia species secure generalist pollinators in invaded communities

    Science.gov (United States)

    Montesinos, Daniel; Castro, Sílvia; Rodríguez-Echeverría, Susana

    2016-07-01

    Exotic entomophilous plants need to establish effective pollinator interactions in order to succeed after being introduced into a new community, particularly if they are obligatory outbreeders. By establishing these novel interactions in the new non-native range, invasive plants are hypothesised to drive changes in the composition and functioning of the native pollinator community, with potential impacts on the pollination biology of native co-flowering plants. We used two different sites in Portugal, each invaded by a different acacia species, to assess whether two native Australian trees, Acacia dealbata and Acacia longifolia, were able to recruit pollinators in Portugal, and whether the pollinator community visiting acacia trees differed from the pollinator communities interacting with native co-flowering plants. Our results indicate that in the invaded range of Portugal both acacia species were able to establish novel mutualistic interactions, predominantly with generalist pollinators. For each of the two studied sites, only two other co-occurring native plant species presented partially overlapping phenologies. We observed significant differences in pollinator richness and visitation rates among native and non-native plant species, although the study of β diversity indicated that only the native plant Lithodora fruticosa presented a differentiated set of pollinator species. Acacias experienced a large number of visits by numerous pollinator species, but massive acacia flowering resulted in flower visitation rates frequently lower than those of the native co-flowering species. We conclude that the establishment of mutualisms in Portugal likely contributes to the effective and profuse production of acacia seeds in Portugal. Despite the massive flowering of A. dealbata and A. longifolia, native plant species attained similar or higher visitation rates than acacias.

  4. Seed Removal Increased by Scramble Competition with an Invasive Species.

    Directory of Open Access Journals (Sweden)

    Rebecca L Minor

    Full Text Available Competition for seeds has a major influence on the evolution of granivores and the plants on which they rely. The complexity of interactions and coevolutionary relationships vary across forest types. The introduction of non-native granivores has considerable potential to alter seed dispersal dynamics. Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As biological invasions continue to rise, it is important to understand mechanisms to build up strategies to mitigate the threat. Our field experiment quantified the impact of introduced Abert's squirrels (Sciurus aberti on rates of seed removal within the range of critically endangered Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis, which consumes similar foods. In the presence of invasive Abert's squirrels, the time cones were removed was faster than when the invasive was excluded, accounting for a median removal time of cones available to red and Abert's squirrels that is 32.8% less than that of cones available only to the rare native red squirrels. Moreover, in the presence of Abert's squirrels, removal rates are higher at great distance from a territorial red squirrel larderhoard and in more open portions of the forest, which suggests differential patterns of seed dispersal. The impact on food availability as a result of cone removal by Abert's squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Furthermore, the magnitude and differential spatial patterns of seed removal suggest that non-native granivores may have impacts on forest regeneration and structure.

  5. When can efforts to control nuisance and invasive species backfire?

    Science.gov (United States)

    Zipkin, E.F.; Kraft, C.E.; Cooch, E.G.; Sullivan, P.J.

    2009-01-01

    Population control through harvest has the potential to reduce the abundance of nuisance and invasive species. However, demographic structure and density-dependent processes can confound removal efforts and lead to undesirable consequences, such as overcompensation (an increase in abundance in response to harvest) and instability (population cycling or chaos). Recent empirical studies have demonstrated the potential for increased mortality (such as that caused by harvest) to lead to overcompensation and instability in plant, insect, and fish populations. We developed a general population model with juvenile and adult stages to help determine the conditions under which control harvest efforts can produce unintended outcomes. Analytical and simulation analyses of the model demonstrated that the potential for overcompensation as a result of harvest was significant for species with high fecundity, even when annual stage-specific survivorship values were fairly low. Population instability as a result of harvest occurred less frequently and was only possible with harvest strategies that targeted adults when both fecundity and adult survivorship were high. We considered these results in conjunction with current literature on nuisance and invasive species to propose general guidelines for assessing the risks associated with control harvest based on life history characteristics of target populations. Our results suggest that species with high per capita fecundity (over discrete breeding periods), short juvenile stages, and fairly constant survivorship rates are most likely to respond undesirably to harvest. It is difficult to determine the extent to which overcompensation and instability could occur during real-world removal efforts, and more empirical removal studies should be undertaken to evaluate population-level responses to control harvests. Nevertheless, our results identify key issues that have been seldom acknowledged and are potentially generic across taxa

  6. Lability of heavy metal species in aquatic humic substances characterized by ion exchange with cellulose phosphate.

    Science.gov (United States)

    Rocha, J C; Toscano, I A; Burba, P

    1997-01-01

    Labile metal species in aquatic humic substances (HSs) were characterized by ion exchange on cellulose phosphate (CellPhos) by applying an optimized batch procedure. The HSs investigated were pre-extracted from humic-rich waters by ultrafiltration and a resin XAD 8 procedure. The HS-metal species studied were formed by complexation with Cd(II), Ni(II), Cu(II), Mn(II) and Pb(II) as a function of time and the ratio ions to HSs. The kinetics and reaction order of this exchange process were studied. At the beginning ( Pb > Mn > Ni > Cd. The required metal determinations were carried out by atomic absorption spectrometry.

  7. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

    OpenAIRE

    Olumide A. Odeyemi; Ahmad, Asmat

    2015-01-01

    This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics – Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole...

  8. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

    OpenAIRE

    Olumide A. Odeyemi; Asmat Ahmad

    2017-01-01

    This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics – Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole...

  9. Willapa NWR: Initial Survey Instructions for Invasive Species Mapping and Monitoring - Spartina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Invasive plant species are ubiquitous in the Northwest and cover large areas of the Refuge. If new invasions can be contained early, large infestations can often be...

  10. Count your eggs before they invade: identifying and quantifying egg clutches of two invasive apple snail species (Pomacea.

    Directory of Open Access Journals (Sweden)

    Colin H Kyle

    Full Text Available Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and

  11. Elucidating the diversity of aquatic microdochium and trichoderma species and their activity against the fish pathogen Saprolegnia diclina

    NARCIS (Netherlands)

    Liu, Yiying; Zachow, Christin; Raaijmakers, J.M.; Bruijn, De Irene

    2016-01-01

    Animals and plants are increasingly threatened by emerging fungal and oomycete diseases. Amongst oomycetes, Saprolegnia species cause population declines in aquatic animals, especially fish and amphibians, resulting in significant perturbation in biodiversity, ecological balance and food security

  12. Mechanisms controlling the distribution of two invasive Bromus species

    Directory of Open Access Journals (Sweden)

    Olga Bykova

    2014-03-01

    Full Text Available In order to predict future range shifts for invasive species it is important to explore their ability to acclimate to the new environment and understand physiological and reproductive constraints controlling their distribution. My dissertation studied mechanisms by which temperature may affect the distribution of two aggressive plant invaders in North America, Bromus tectorum and Bromus rubens. I first evaluated winter freezing tolerance of Bromus species and demonstrated that the mechanism explaining their distinct northern range limits is different acquisition time of freezing tolerance. While B. rubens has a slower rate of freezing acclimation that leads to intolerance of sudden, late-autumn drops in temperature below -12°C, B. tectorum rapidly hardens and so is not impacted by the sudden onset of severe late-autumn cold. In addition, the analysis of male reproductive development and seed production showed that neither species produces seed at or above 36°C, due to complete pollen sterility, which might trigger climate-mediated range contractions at B. tectorum and B. rubens southern margins. Finally, a detailed gas-exchange analysis combined with biochemical modelling demonstrated that both species acclimate to a broad range of temperatures and photosynthetic response to temperature does not explain their current range separation.

  13. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?

    Directory of Open Access Journals (Sweden)

    Susana Pallarés

    2016-08-01

    Full Text Available Background Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to drying stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. Methods We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae with contrasting habitat specificity (lentic vs. lotic systems and different salinity optima from fresh- to hypersaline waters. We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate under controlled exposure to desiccation, and explored their variability within and between species. Results Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens’ initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Discussion Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin.

  14. Critical considerations for the application of environmental DNA methods to detect aquatic species

    Science.gov (United States)

    Goldberg, Caren S.; Turner, Cameron R.; Deiner, Kristy; Klymus, Katy E.; Thomsen, Philip Francis; Murphy, Melanie A.; Spear, Stephen F.; McKee, Anna; Oyler-McCance, Sara J.; Cornman, Robert S.; Laramie, Matthew B.; Mahon, Andrew R.; Lance, Richard F.; Pilliod, David S.; Strickler, Katherine M.; Waits, Lisette P.; Fremier, Alexander K.; Takahara, Teruhiko; Herder, Jelger E.; Taberlet, Pierre

    2016-01-01

    Species detection using environmental DNA (eDNA) has tremendous potential for contributing to the understanding of the ecology and conservation of aquatic species. Detecting species using eDNA methods, rather than directly sampling the organisms, can reduce impacts on sensitive species and increase the power of field surveys for rare and elusive species. The sensitivity of eDNA methods, however, requires a heightened awareness and attention to quality assurance and quality control protocols. Additionally, the interpretation of eDNA data demands careful consideration of multiple factors. As eDNA methods have grown in application, diverse approaches have been implemented to address these issues. With interest in eDNA continuing to expand, supportive guidelines for undertaking eDNA studies are greatly needed.Environmental DNA researchers from around the world have collaborated to produce this set of guidelines and considerations for implementing eDNA methods to detect aquatic macroorganisms.Critical considerations for study design include preventing contamination in the field and the laboratory, choosing appropriate sample analysis methods, validating assays, testing for sample inhibition and following minimum reporting guidelines. Critical considerations for inference include temporal and spatial processes, limits of correlation of eDNA with abundance, uncertainty of positive and negative results, and potential sources of allochthonous DNA.We present a synthesis of knowledge at this stage for application of this new and powerful detection method.

  15. Minimizing Risks of Invasive Alien Plant Species in Tropical Production Forest Management

    Directory of Open Access Journals (Sweden)

    Michael Padmanaba

    2014-08-01

    Full Text Available Timber production is the most pervasive human impact on tropical forests, but studies of logging impacts have largely focused on timber species and vertebrates. This review focuses on the risk from invasive alien plant species, which has been frequently neglected in production forest management in the tropics. Our literature search resulted in 114 publications with relevant information, including books, book chapters, reports and papers. Examples of both invasions by aliens into tropical production forests and plantation forests as sources of invasions are presented. We discuss species traits and processes affecting spread and invasion, and silvicultural practices that favor invasions. We also highlight potential impacts of invasive plant species and discuss options for managing them in production forests. We suggest that future forestry practices need to reduce the risks of plant invasions by conducting surveillance for invasive species; minimizing canopy opening during harvesting; encouraging rapid canopy closure in plantations; minimizing the width of access roads; and ensuring that vehicles and other equipment are not transporting seeds of invasive species. Potential invasive species should not be planted within dispersal range of production forests. In invasive species management, forewarned is forearmed.

  16. Assessment of mechanisms of metal-induced reproductive toxicity in aquatic species as a biomarker of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.; George, W.; Preslan, J. [and others

    1996-05-02

    This project discusses the following studies: identification and quantitation of heavy metals and petroleum products present in Bayou Trepagnier relative to control sites; assessment of the uptake and bioaccumulation of metals and organic contaminants of interest in aquatic species; establishment and use of polarographic methods for use in metal speciation studies to identify specific chemical forms present in sediments, waters and organism; and evaluation of contaminants on reproductive function of aquatic species as potential biomarkers of exposure. 14 refs.

  17. Annotated list of marine alien species in the Mediterranean with records of the worst invasive species

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2012-12-01

    Full Text Available This collaborative effort by many specialists across the Mediterranean presents an updated annotated list of alien marine species in the Mediterranean Sea. Alien species have been grouped into six broad categories namely established, casual, questionable, cryptogenic, excluded and invasive, and presented in lists of major ecofunctional/taxonomic groups. The establishment success within each group is provided while the questionable and excluded records are commented in brief. A total of 963 alien species have been reported from the Mediterranean until December 2005, 218 of which have been classified as excluded (23% leaving 745 of the recorded species as valid aliens. Of these 385 (52% are already well established, 262 (35% are casual records, while 98 species (13% remain “questionable” records. The species cited in this work belong mostly to zoobenthos and in particular to Mollusca and Crustacea, while Fish and Phytobenthos are the next two groups which prevail among alien biota in the Mediterranean. The available information depends greatly on the taxonomic group examined. Thus, besides the three groups explicitly addressed in the CIESM atlas series (Fish, Decapoda/Crustacea and Mollusca, which are however updated in the present work, Polychaeta, Phytobenthos, Phytoplankton and Zooplankton are also addressed in this study. Among other zoobenthic taxa sufficiently covered in this study are Echinodermata, Sipuncula, Bryozoa and Ascidiacea. On the contrary, taxa such as Foraminifera, Amphipoda and Isopoda, that are not well studied in the Mediterranean, are insufficiently covered. A gap of knowledge is also noticed in Parasites, which, although ubiquitous and pervasive in marine systems, have been relatively unexplored as to their role in marine invasions. Conclusively the lack of funding purely systematic studies in the region has led to underestimation of the number of aliens in the Mediterranean. Emphasis is put on those species that are

  18. Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

    Science.gov (United States)

    Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene

    2015-07-01

    The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests.

  19. Impact of Anthropogenic Noise on Aquatic Animals: From Single Species to Community-Level Effects.

    Science.gov (United States)

    Sabet, Saeed Shafiei; Neo, Yik Yaw; Slabbekoorn, Hans

    2016-01-01

    Anthropogenic noise underwater is on the rise and may affect aquatic animals of marine and freshwater ecosystems. Many recent studies concern some sort of impact assessment of a single species. Few studies addressed the noise impact on species interactions underwater, whereas there are some studies that address community-level impact but only on land in air. Key processes such as predator-prey or competitor interactions may be affected by the masking of auditory cues, noise-related disturbance, or attentional interference. Noise-associated changes in these interactions can cause shifts in species abundance and modify communities, leading to fundamental ecosystem changes. To gain further insight into the mechanism and generality of earlier findings, we investigated the impact on both a predator and a prey species in captivity, zebrafish (Danio rerio) preying on waterfleas (Daphnia magna).

  20. Toward a global information system for invasive species

    Science.gov (United States)

    Ricciardi, Anthony; Steiner, William W.M.; Mack, Richard N.; Simberloff, Daniel

    2000-01-01

    The growing frequency and impact of biological invasions worldwide threaten biodiversity, ecosystem functioning, resource availability, national economies, and human health (Ruesink et al. 1995, Simberloff 1996, Vitousek et al. 1997). Organisms are spreading into new regions at unprecedented rates. As a result, hundreds to thousands of nonindigenous species of invertebrates, vertebrates, plants, bacteria, and fungi have become established in all but the most remote areas of the planet (Vitousek et al. 1997). Recent examples are abundant and, in some cases, alarming. Cholera bacteria and toxic dinoflagellates have been discovered in the ballast waters of cargo ships (McCarthy and Khambaty 1994, Hallegraeff 1998). Asian tiger mosquitos—vectors of yellow fever and encephalitis—have spread to new continents in imported truck tires (Moore et al. 1988). Pasture and crop lands in Australia are being invaded by Parthenium, an aggressive Caribbean weed that causes severe allergic reactions in livestock and humans (Evans 1997). Rapid and widespread dieoffs of native freshwater mussels are occurring in the wake of the zebra mussel invasion in North America (Ricciardi et al. 1998). [[AQ4]Hardwood trees in American cities are being killed by Asian long-horned beetles introduced with wooden packing crates (Haack et al. 1997).

  1. Scale-dependent effects of habitat area on species interaction networks: invasive species alter relationships

    Directory of Open Access Journals (Sweden)

    Sugiura Shinji

    2012-07-01

    Full Text Available Abstract Background The positive relationship between habitat area and species number is considered a fundamental rule in ecology. This relationship predicts that the link number of species interactions increases with habitat area, and structure is related to habitat area. Biological invasions can affect species interactions and area relationships. However, how these relationships change at different spatial scales has remained unexplored. We analysed understory plant–pollinator networks in seven temperate forest sites at 20 spatial scales (radius 120–2020 m to clarify scale-associated relationships between forest area and plant–pollinator networks. Results The pooled data described interactions between 18 plant (including an exotic and 89 pollinator (including an exotic species. The total number of species and the number of interaction links between plant and pollinator species were negatively correlated with forest area, with the highest correlation coefficient at radii of 1520 and 1620 m, respectively. These results are not concordant with the pattern predicted by species–area relationships. However, when associations with exotic species were excluded, the total number of species and the number of interaction links were positively correlated with forest area (the highest correlation coefficient at a radius of 820 m. The network structure, i.e., connectance and nestedness, was also related to forest area (the highest correlation coefficients at radii of 720–820 m, when associations with exotics were excluded. In the study area, the exotic plant species Alliaria petiolata, which has invaded relatively small forest patches surrounded by agricultural fields, may have supported more native pollinator species than initially expected. Therefore, this invasive plant may have altered the original relationships between forest area and plant–pollinator networks. Conclusions Our results demonstrate scale-dependent effects of forest

  2. Distribution patterns of invasive alien species in Alabama, USA

    Directory of Open Access Journals (Sweden)

    Xiongwen Chen

    2012-12-01

    Full Text Available Invasive alien species (IAS cause environmental and economical problems. How to effectively manage all IAS at a large area is a challenge.Hypotheses about IAS (such as the “human activity” hypothesis, the “biotic acceptance” and the “biotic resistance” have been proposedfrom numerous studies. Here the state of Alabama in USA, widely occupied by IAS, is used as a case study for characterizing the emergentpatterns of IAS. The results indicate that most IAS are located in metropolitan areas and in the Black Belt area which is a historical intensiveland use area. There are positive relationships between the richness of IAS and the change of human population, the species richness and thenumber of endangered species, as well as the total road length and farmland area across Alabama. This study partially supports the abovethree hypotheses and provides a general pattern of local IAS. Based on possible processes related with IAS, some implications forstrategically managing local IAS are discussed.

  3. Synergistic impacts by an invasive amphipod and an invasive fish explain native gammarid extinction

    OpenAIRE

    Beggel, S.; Brandner, J.; Cerwenka, A. F.; Geist, J.

    2016-01-01

    Background Worldwide freshwater ecosystems are increasingly affected by invasive alien species. In particular, Ponto-Caspian gobiid fishes and amphipods are suspected to have pronounced effects on aquatic food webs. However, there is a lack of systematic studies mechanistically testing the potential synergistic effects of invasive species on native fauna. In this study we investigated the interrelations between the invasive amphipod Dikerogammarus villosus and the invasive fish species Neogob...

  4. Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities

    Science.gov (United States)

    Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

    2013-01-01

    Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

  5. Teaching Farmers and Commercial Pesticide Applicators about Invasive Species in Pesticide Training Workshops

    Science.gov (United States)

    Wyatt, Gary J.; Herzfeld, Dean; Haugen-Brown, Tana

    2015-01-01

    Farmers and agricultural professionals who are aware of species likely to invade agricultural landscapes can be active participants in efforts to detect invasive species. To reach this audience we created a short invasive species program and added it to the existing and required pesticide applicator recertification workshops. We highlighted four…

  6. Analytical fractionation of aquatic humic substances and their metal species by means of multistage ultrafiltration.

    Science.gov (United States)

    Aster, B; Burba, P; Broekaert, J A

    1996-03-01

    The molecular-size fractionation of aquatic humic substances (HS) and their metal species by means of a novel sequential-stage ultrafiltration (UF) device equipped with five appropriate ultramembranes (1, 5, 10, 50 and 100 kD) is described. First of all, the concentration dynamics of macromolecules, particulary HS, during five-stage UF and its subsequent washing step has been modelled. Based on these results, the fractionation of aquatic HS (from ground and bog water) by means of multistage UF has been optimized for an analytical scale (10 ml sample, 1 mg/ml HS, 10 ml washing solution, pH 6.0). The molecular size-distribution of selected aquatic HS (BOC 1/2 from the "DFG-Versuchsfeld Bocholt", VM 5 from "Venner Moor", Germany) studied by five-stage UF exhibited strong systematic influences of the procedure used for their isolation. The molecular-size distribution of HS obtained by on-line UF and gel permeation chromatography (GPC) showed a satisfactory agreement in the range 1-50 kD. Moreover, when interrupting multistage UF for > 48 h a slow transformation in the HS samples has been found as gradually additional HS fractions of complexation time. Metal determinations as carried out by flame AAS, showed that considerable metal fractions in HS especially are present in molecules > 50 kD, which seemed to be rather acid-inert. With complexation times of 10 kD) has been found.

  7. Predicting aquatic toxicities of chemical pesticides in multiple test species using nonlinear QSTR modeling approaches.

    Science.gov (United States)

    Basant, Nikita; Gupta, Shikha; Singh, Kunwar P

    2015-11-01

    In this study, we established nonlinear quantitative-structure toxicity relationship (QSTR) models for predicting the toxicities of chemical pesticides in multiple aquatic test species following the OECD (Organization for Economic Cooperation and Development) guidelines. The decision tree forest (DTF) and decision tree boost (DTB) based QSTR models were constructed using a pesticides toxicity dataset in Selenastrum capricornutum and a set of six descriptors. Other six toxicity data sets were used for external validation of the constructed QSTRs. Global QSTR models were also constructed using the combined dataset of all the seven species. The diversity in chemical structures and nonlinearity in the data were evaluated. Model validation was performed deriving several statistical coefficients for the test data and the prediction and generalization abilities of the QSTRs were evaluated. Both the QSTR models identified WPSA1 (weighted charged partial positive surface area) as the most influential descriptor. The DTF and DTB QSTRs performed relatively better than the single decision tree (SDT) and support vector machines (SVM) models used as a benchmark here and yielded R(2) of 0.886 and 0.964 between the measured and predicted toxicity values in the complete dataset (S. capricornutum). The QSTR models applied to six other aquatic species toxicity data yielded R(2) of >0.92 (DTF) and >0.97 (DTB), respectively. The prediction accuracies of the global models were comparable with those of the S. capricornutum models. The results suggest for the appropriateness of the developed QSTR models to reliably predict the aquatic toxicity of chemicals and can be used for regulatory purpose.

  8. Insecticide species sensitivity distributions: importance of test species selection and relevance to aquatic ecosystems

    NARCIS (Netherlands)

    Maltby, L.; Blake, N.; Brock, T.C.M.; Brink, van den P.J.

    2005-01-01

    Single-species acute toxicity data and (micro)mesocosm data were collated for 16 insecticides. These data were used to investigate the importance of test-species selection in constructing species sensitivity distributions (SSDs) and the ability of estimated hazardous concentrations (HCs) to protect

  9. Invasive species: Ocean ecosystem case studies for earth systems and environmental sciences

    Science.gov (United States)

    Schofield, Pam; Brown, Mary E.

    2016-01-01

    Marine species are increasingly transferred from areas where they are native to areas where they are not. Some nonnative species become invasive, causing undesirable impacts to environment, economy and/or human health. Nonnative marine species can be introduced through a variety of vectors, including shipping, trade, inland corridors (such as canals), and others. Effects of invasive marine species can be dramatic and irreversible. Case studies of four nonnative marine species are given (green crab, comb jelly, lionfish and Caulerpa algae).

  10. Aliens in Transylvania: risk maps of invasive alien plant species in Central Romania

    Directory of Open Access Journals (Sweden)

    Heike Zimmermann

    2015-01-01

    Full Text Available Using the MAXENT algorithm, we developed risk maps for eight invasive plant species in southern Transylvania, Romania, a region undergoing drastic land-use changes. Our findings show that invasion risk increased with landscape heterogeneity. Roads and agricultural areas were most prone to invasion, whereas forests were least at risk.

  11. Non-indigenous bamboo along headwater streams of the Luquillo Mountains, Puerto Rico: Leaf fall, aquatic leaf decay and patterns of invasion

    Science.gov (United States)

    O'Connor, P. J.; Covich, A.P.; Scatena, F.N.; Loope, L.L.

    2000-01-01

    The introduction of bamboo to montane rain forests of the Luquillo Mountains, Puerto Rico in the 1930s and 1940s has led to present-day bamboo monocultures in numerous riparian areas. When a non-native species invades a riparian ecosystem, in-stream detritivores can be affected. Bamboo dynamics expected to influence stream communities in the Luquillo Experimental Forest (LEF) were examined. Based on current distributions, bamboo has spread down-stream at a rate of 8 m y-1. Mean growth rate of bamboo culms was 15.3 cm d-1. Leaf fall from bamboo stands exceeded that of native mixed-species forest by c. 30% over a 10-mo study. Bamboo leaves (k = -0.021), and leaves from another abundant riparian exotic, Syzygium jambos (Myrtaceae) (k = -0.018), decayed at relatively slow rates when submerged in streams in fine-mesh bags which excluded macro-invertebrate leaf processors. In a second study, with leaf processors present, bamboo decay rates remained unchanged (k = -0.021), while decay rates of S. jambos increased (k = -0.037). Elemental losses from bamboo leaves in streams were rapid, further suggesting a change in riparian zone/stream dynamics following bamboo invasion. As non-indigenous bamboos spread along Puerto Rico streams, they are likely to alter aquatic communities dependent on leaf input.

  12. Evolutionary responses of native plant species to invasive plants: a review.

    Science.gov (United States)

    Oduor, Ayub M O

    2013-12-01

    Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.

  13. Occurrence and diversity of clinically important Vibrio species in the aquatic environments of Georgia

    Directory of Open Access Journals (Sweden)

    Tamari eKokashvili

    2015-10-01

    Full Text Available Among the more than 70 different Vibrio species inhabiting marine, estuarine, and freshwater ecosystems, 12 are recognized as human pathogens. The warm subtropical climate of the Black Sea coastal area and inland regions of Georgia likely provides a favorable environment for various Vibrio species. From 2006 to 2009, the abundance, ecology, and diversity of clinically important Vibrio species were studied in different locations in Georgia and across seasons. Over a 33-month period, 1,595 presumptive Vibrio isolates were collected from the Black Sea (n=657 and freshwater lakes around Tbilisi (n=938. Screening of a subset of 440 concentrated and enriched water samples by PCR-electrospray ionization/mass spectrometry (PCR-ESI/MS detected the presence of DNA from eight clinically important Vibrio species: V. cholerae, V. parahaemolyticus, V. vulnificus, V. mimicus, V. alginolyticus, V. harveyi, V. metschnikovii, and V. cincinnatiensis. Almost ninety percent of PCR/ESI-MS samples positive for Vibrio species were collected from June through November. Three important human pathogenic Vibrio species (V. cholerae, V. parahaemolyticus, and V. vulnificus were detected in 62.8%, 37.8%, and 21.4% of samples testing positive for vibrios, respectively. The results of these activities suggest that natural reservoirs for human-pathogenic Vibrios exist in Georgian aquatic environments. Water temperature at all sampling sites was positively correlated with the abundance of clinically important Vibrio spp. (except V. metschnikovii and salinity was correlated with species composition at particular Black Sea sites as well as inland reservoirs.

  14. A Source Area Approach Demonstrates Moderate Predictive Ability but Pronounced Variability of Invasive Species Traits.

    Directory of Open Access Journals (Sweden)

    Günther Klonner

    Full Text Available The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value, habitat use (agricultural and ruderal habitats, occurrence under the montane belt, and propagule pressure (frequency were most closely associated with invasiveness. However, even the best multiple model, including interactions, only explained a moderate fraction of the differences in invasive success. In addition, multidimensional variability in trait space was even larger among invasive than among non-invasive species. This pronounced variability suggests that invasive success has a considerable idiosyncratic component and is probably highly context specific. We conclude that basing risk assessment protocols on species trait profiles will probably face hardly reducible uncertainties.

  15. Making a Bad Situation Worse: An Invasive Species Altering the Balance of Interactions between Local Species

    Science.gov (United States)

    2016-01-01

    Biological invasions pose a significant threat to biodiversity, especially on oceanic islands. One of the primary explanations for the success of plant invaders is direct suppression of competitors. However, indirect interactions can also be important, although they are often overlooked in studies on biological invasion. The shrub Leucaena leucocephala is a widespread island invader with putative allelopathic effects on the germination and growth of other species. We quantified the impact of Leucaena on plant communities richness on an oceanic Brazilian island and, through nursery experiments, investigated the potential for allelopathic effects on the germination of Erythrina velutina, a native species that is often absent from stands of Leucaena. Additionally, in a manipulative field experiment, we examined the direct and indirect effects (mediated by the native species Capparis flexuosa) of the invader on the development of Erythrina. The species richness in invaded sites was lower than in uninvaded sites, and Capparis was the only native species that was frequently present in invaded sites. In the nursery experiments, we found no evidence that Leucaena affects the germination of Erythrina. In the field experiments, the odds of Erythrina germination were lower in the presence of Leucaena litter, but higher in the presence of Leucaena trees. However, the survival and growth of Erythrina were considerably inhibited by the presence of Leucaena trees. The isolated effect of native Capparis on the germination and growth of Erythrina varied from positive to neutral. However, when Capparis and Leucaena were both present, their combined negative effects on Erythrina were worse than the effect of Leucaena alone, which may be attributed to indirect effects. This study provides the first empirical evidence that the balance of the interactions between native species can shift from neutral/positive to negative in the presence of an exotic species. PMID:27010846

  16. Making a Bad Situation Worse: An Invasive Species Altering the Balance of Interactions between Local Species.

    Science.gov (United States)

    Mello, Thayná Jeremias; Oliveira, Alexandre Adalardo de

    2016-01-01

    Biological invasions pose a significant threat to biodiversity, especially on oceanic islands. One of the primary explanations for the success of plant invaders is direct suppression of competitors. However, indirect interactions can also be important, although they are often overlooked in studies on biological invasion. The shrub Leucaena leucocephala is a widespread island invader with putative allelopathic effects on the germination and growth of other species. We quantified the impact of Leucaena on plant communities richness on an oceanic Brazilian island and, through nursery experiments, investigated the potential for allelopathic effects on the germination of Erythrina velutina, a native species that is often absent from stands of Leucaena. Additionally, in a manipulative field experiment, we examined the direct and indirect effects (mediated by the native species Capparis flexuosa) of the invader on the development of Erythrina. The species richness in invaded sites was lower than in uninvaded sites, and Capparis was the only native species that was frequently present in invaded sites. In the nursery experiments, we found no evidence that Leucaena affects the germination of Erythrina. In the field experiments, the odds of Erythrina germination were lower in the presence of Leucaena litter, but higher in the presence of Leucaena trees. However, the survival and growth of Erythrina were considerably inhibited by the presence of Leucaena trees. The isolated effect of native Capparis on the germination and growth of Erythrina varied from positive to neutral. However, when Capparis and Leucaena were both present, their combined negative effects on Erythrina were worse than the effect of Leucaena alone, which may be attributed to indirect effects. This study provides the first empirical evidence that the balance of the interactions between native species can shift from neutral/positive to negative in the presence of an exotic species.

  17. Temperature-size responses match latitudinal-size clines in arthropods, revealing critical differences between aquatic and terrestrial species

    DEFF Research Database (Denmark)

    Horne, C.R.; Hirst, Andrew G.; Atkinson, D.

    2015-01-01

    of these gradients to date, and find that their direction and magnitude co-vary among 12 arthropod orders (r2 = 0.72). Body size in aquatic species generally reduces with both warming and decreasing latitude, whereas terrestrial species have much reduced and even opposite gradients. These patterns support...... the prediction that oxygen limitation is a major controlling factor in water, but not in air. Furthermore, voltinism explains much of the variation in T-S and L-S patterns in terrestrial but not aquatic species. While body size decreases with warming and with decreasing latitude in multivoltine terrestrial...

  18. Establishing research and management priorities for invasive water primroses (Ludwigia spp.)

    Science.gov (United States)

    This technical report provides background information on invasive, aquatic Ludwigia species to assist aquatic resource managers. The report includes a description of the problems caused by these invasive plant species and why their current aggressive spread should concern resource managers and poli...

  19. Aquatic toxicity structure-activity relationships for the zwitterionic surfactant alkyl dimethyl amine oxide to several aquatic species and a resulting species sensitivity distribution.

    Science.gov (United States)

    Belanger, Scott E; Brill, Jessica L; Rawlings, Jane M; McDonough, Kathleen M; Zoller, Ann C; Wehmeyer, Kenneth R

    2016-12-01

    Amine oxide (AO) is a cationically charged surfactant at environmental pH and has previously been assessed in the OECD (Organization for Economic Cooperation and Development) High Production Volume (HPV) chemicals program. Typical of cationic chemicals, AO is highly aquatically toxic. In this study we vastly improve the knowledge of AO toxicity by developing acute Quantitative Structure Activity Relationships (QSARs) for an alga (Desmodesmus subspicatus), an invertebrate (Daphnia magna) and a fish (Danio rerio) using the appropriate array of OECD Test Guidelines. A chronic toxicity QSAR was also determined for the most sensitive taxon, Desmodesmus. Pure AO spanning the chain lengths of C8 to C16 were tested individually with trace analytical confirmation of exposures in all tests. The QSARs were all of high quality (R(2) 0.92-0.98) with slopes ranging from -0.338 to -0.484. QSARs were then used to normalize toxicity outcomes for a larger, previously published data set used in HPV, European REACH (Registration, Evaluation, and Authorization of Chemicals), and peer reviewed publications. Two additional species, Lemna gibba (macrophyte) and Ankistrodesmus falcatus (alga) were studied in exposures to dodecyl (C12) AO to provide sufficient taxonomic diversity to conduct a Species Sensitivity Distribution (SSD) analysis. The SSD 5th percentile hazardous concentration (HC5) to C12 AO was found to be 0.052mg/L which is similar to an existing AO 28-d, 3-community periphyton community bioassay normalized to C12 AO (No-observed-effect-concentration or NOEC=0.152mg/L). The statistical properties of the SSD was probed suggesting that new studies of additional taxa would be required that were at least 10-fold more sensitive than the most sensitive taxon to move the HC5 lower by a factor of 3. The overall AO hazard assessment suggests a large margin of safety relative to published environmental exposure data.

  20. Expansion of invasive species on ombrotrophic bogs: desiccation or high N deposition?

    NARCIS (Netherlands)

    Tomassen, H.B.M.; Smolders, A.J.P.; Limpens, J.; Lamers, L.P.M.; Roelofs, J.G.M.

    2004-01-01

    1. In many ombrotrophic bog areas the invasion of grass (e.g. Molinia caerulea) and tree (e.g. Betula pubescens) species has become a major problem. We investigated whether the invasion of such species is due to high atmospheric nitrogen (N) deposition by conducting a fertilization experiment. 2. Th

  1. Invasive species change detection using artificial neural networks and CASI hyperspectral imagery

    Science.gov (United States)

    For monitoring and controlling the extent and intensity of an invasive species, a direct multi-date image classification method was applied in invasive species (saltcedar) change detection in the study area of Lovelock, Nevada. With multi-date Compact Airborne Spectrographic Imager (CASI) hyperspec...

  2. Phenotypic plasticity and population differentiation in an ongoing species invasion.

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    Full Text Available The ability to succeed in diverse conditions is a key factor allowing introduced species to successfully invade and spread across new areas. Two non-exclusive factors have been suggested to promote this ability: adaptive phenotypic plasticity of individuals, and the evolution of locally adapted populations in the new range. We investigated these individual and population-level factors in Polygonum cespitosum, an Asian annual that has recently become invasive in northeastern North America. We characterized individual fitness, life-history, and functional plasticity in response to two contrasting glasshouse habitat treatments (full sun/dry soil and understory shade/moist soil in 165 genotypes sampled from nine geographically separate populations representing the range of light and soil moisture conditions the species inhabits in this region. Polygonum cespitosum genotypes from these introduced-range populations expressed broadly similar plasticity patterns. In response to full sun, dry conditions, genotypes from all populations increased photosynthetic rate, water use efficiency, and allocation to root tissues, dramatically increasing reproductive fitness compared to phenotypes expressed in simulated understory shade. Although there were subtle among-population differences in mean trait values as well as in the slope of plastic responses, these population differences did not reflect local adaptation to environmental conditions measured at the population sites of origin. Instead, certain populations expressed higher fitness in both glasshouse habitat treatments. We also compared the introduced-range populations to a single population from the native Asian range, and found that the native population had delayed phenology, limited functional plasticity, and lower fitness in both experimental environments compared with the introduced-range populations. Our results indicate that the future spread of P. cespitosum in its introduced range will likely be

  3. 77 FR 23494 - Invasive Species Advisory Committee; Request for Nominations

    Science.gov (United States)

    2012-04-19

    ..., providing for their control, and minimizing the economic, ecological, and human health impacts that invasive... education; science and environmental journalism and outreach; natural resource economics; tribal...

  4. Global threats from invasive alien species in the twenty-first century and national response capacities

    Science.gov (United States)

    Early, Regan; Bradley, Bethany A.; Dukes, Jeffrey S.; Lawler, Joshua J.; Olden, Julian D.; Blumenthal, Dana M.; Gonzalez, Patrick; Grosholz, Edwin D.; Ibañez, Ines; Miller, Luke P.; Sorte, Cascade J. B.; Tatem, Andrew J.

    2016-01-01

    Invasive alien species (IAS) threaten human livelihoods and biodiversity globally. Increasing globalization facilitates IAS arrival, and environmental changes, including climate change, facilitate IAS establishment. Here we provide the first global, spatial analysis of the terrestrial threat from IAS in light of twenty-first century globalization and environmental change, and evaluate national capacities to prevent and manage species invasions. We find that one-sixth of the global land surface is highly vulnerable to invasion, including substantial areas in developing economies and biodiversity hotspots. The dominant invasion vectors differ between high-income countries (imports, particularly of plants and pets) and low-income countries (air travel). Uniting data on the causes of introduction and establishment can improve early-warning and eradication schemes. Most countries have limited capacity to act against invasions. In particular, we reveal a clear need for proactive invasion strategies in areas with high poverty levels, high biodiversity and low historical levels of invasion. PMID:27549569

  5. Global threats from invasive alien species in the twenty-first century and national response capacities.

    Science.gov (United States)

    Early, Regan; Bradley, Bethany A; Dukes, Jeffrey S; Lawler, Joshua J; Olden, Julian D; Blumenthal, Dana M; Gonzalez, Patrick; Grosholz, Edwin D; Ibañez, Ines; Miller, Luke P; Sorte, Cascade J B; Tatem, Andrew J

    2016-08-23

    Invasive alien species (IAS) threaten human livelihoods and biodiversity globally. Increasing globalization facilitates IAS arrival, and environmental changes, including climate change, facilitate IAS establishment. Here we provide the first global, spatial analysis of the terrestrial threat from IAS in light of twenty-first century globalization and environmental change, and evaluate national capacities to prevent and manage species invasions. We find that one-sixth of the global land surface is highly vulnerable to invasion, including substantial areas in developing economies and biodiversity hotspots. The dominant invasion vectors differ between high-income countries (imports, particularly of plants and pets) and low-income countries (air travel). Uniting data on the causes of introduction and establishment can improve early-warning and eradication schemes. Most countries have limited capacity to act against invasions. In particular, we reveal a clear need for proactive invasion strategies in areas with high poverty levels, high biodiversity and low historical levels of invasion.

  6. 外来侵袭物种的法律定义%Legal Definition on Alien Invasive Species

    Institute of Scientific and Technical Information of China (English)

    高敏

    2005-01-01

    Agriculture,economy,ecological environment and human health are heavily threatened by alien invasive species ,Alien invasive species is spreading in our country,How to prevent,control and destroy alien invasive species through systems and regulations is problem for related legislation to resolve,However,how to deline alien species,invasive and introduction is premise of legal control on alien invasive species,and determines scope and offect of legal control,through comparing and analyzing legal definition of other countries.legal definition on alien invasive species in our country is put forwarded in the article。

  7. POST-EXERCISE LACTATE PRODUCTION AND METABOLISM IN THREE SPECIES OF AQUATIC AND TERRESTRIAL DECAPOD CRUSTACEANS

    Science.gov (United States)

    Walsh

    1994-01-01

    Aquatic and terrestrial crustaceans are dependent on both aerobic and anaerobic metabolism for energy production during exercise. Anaerobic energy production is marked by an accumulation of lactate in both muscle tissue and haemolymph, but the metabolic fate of lactate is not clear. Lactate recycling via gluconeogenesis and the potential role of carbonic anhydrase (CA) in supplying bicarbonate for the carboxylation of pyruvate were investigated in three species of decapod crustaceans: Callinectes sapidus (aquatic), Cardisoma guanhumi (semi-terrestrial) and Gecarcinus lateralis (terrestrial). CA activity was found in mitochondria and cytoplasmic fractions of gill, hepatopancreas and muscle of all three species. Significant activities of key enzymes of gluconeogenesis (e.g. pyruvate carboxylase, phosphoenolpyruvate carboxykinase and fructose bisphosphatase), however, could not be detected. Exercise to exhaustion produced a species-specific pattern of accumulation and clearance of lactate in tissue and haemolymph, indicating a differential degree of reliance on anaerobic energy production. Treatment with acetazolamide, a CA inhibitor, did not significantly alter the pattern of lactate dynamics in animals given repeated bouts of exhaustive exercise interspersed with periods of recovery. Injection of [U-14C]lactate resulted in the appearance of label in both muscle glycogen and excreted carbon dioxide, suggesting multiple metabolic fates for lactate. Lactate turnover rates for G. lateralis were similar to those reported for fish. In these animals, gluconeogenesis possibly proceeds via the reversal of pyruvate kinase, or via the typical Cori cycle but so slowly that the uncatalysed supply of bicarbonate is sufficient to keep pace with the low activities of pyruvate carboxylase and the subsequent low rates of pyruvate carboxylation.

  8. In-situ non-invasive device for early detection of fouling in aquatic systems

    KAUST Repository

    Fortunato, Luca

    2017-01-05

    An in-situ, non-destructive sensor device, system and method are provided to detect or assess fouling at a very early stage of development. They can be used to detect or assess fouling on a surface of an aquatic system. They can be used to obtain a depth profile of the fouling. Data concerning the depth profile can be extracted and used to assess the fouling on the surface, in one or more aspects, the method can include providing an optical tomography spectrometer; optically positioning the optical tomography spectrometer in association with a surface of an area to be assessed for fouling in an aqueous system; irradiating the surface; acquiring, from irradiating the surface, a plurality of signals as a function of a distance from the surface at different times; extracting data from the signals as a function of the distance to obtain a depth profile of the surface at the different times; and determining a change in the depth profile between the different times to assess fouling on the surface.

  9. Invasive species in the flora of the Starobilsk grass-meadow steppe (Ukraine

    Directory of Open Access Journals (Sweden)

    Kucher Oksana O.

    2015-06-01

    Full Text Available The results of an investigation of the invasive species in the flora of the Starobilsk grass-meadow steppe are presented. Check-list of alien plant has over 386 species of vascular plants of which 28 species are invasive. We have identified 6 transformer species from the invasive plants. We aggregate data on the entry, distribution history, ecology, occurrence in different plant communities, degree of their naturalization and the habitats where they occur. The leading families of invasive species are: Asteraceae. The basis for this group is presented by origin from the North America and the Mediterranean. With respect to the time of immigration, most of them are kenophytes. By the method of introduction, ksenophytes are dominated; according to the degree of naturalization epoecophytes and agriophytes dominate in this group. With regard to the characteristics of life forms, half of invasive species are terophytes. The vast majority of plants are heliophytes and xeromesophytes. Most species are found in biotopes group I: Cultivated agricultural biotopes; least of all species found in biotopes group F: Biotopes dominated by chamephytes and nanophanerophytes. Only 3 species found in biotopes group F: Biotopes dominated by chamephytesand nanophanerophytes. The maps of distribution of 28 invasive species are provided. Most of the species marked dispersed in more than 30 squares.

  10. Analytical fractionation of aquatic humic substances and their metal species by means of multistage ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Aster, B. [Institute for Spectrochemistry and Applied Spectroscopy, Postfach 10 1352, D-44139 Dortmund (Germany); Burba, P. [Institute for Spectrochemistry and Applied Spectroscopy, Postfach 10 1352, D-44139 Dortmund (Germany); Broekaert, J.A.C. [University of Dortmund, D-44227 Dortmund (Germany)

    1996-03-01

    The molecular-size fractionation of aquatic humic substances (HS) and their metal species by means of a novel sequential-stage ultrafiltration (UF) device equipped with five appropriate ultramembranes (1, 5, 10, 50 and 100 kD) is described. First of all, the concentration dynamics of macromolecules, particulary HS, during five-stage UF and its subsequent washing step has been modelled. Based on these results, the fractionation of aquatic HS (from ground and bog water) by means of multistage UF has been optimized for an analytical scale (10 ml sample, 1 mg/ml HS, 10 ml washing solution, pH 6.0). The molecular size-distribution of selected aquatic HS (BOC 1/2 from the ``DFG-Versuchsfeld Bocholt``, VM 5 from ``Venner Moor``, Germany) studied by five-stage UF exhibited strong systematic influences of the procedure used for their isolation. The molecular-size distribution of HS obtained by on-line UF and gel permeation chromatography (GPC) showed a satisfactory agreement in the range 1-50 kD. Moreover, when interrupting multistage UF for > 48 h a slow transformation in the HS samples has been found as gradually additional HS fractions of < 1 kD have been formed. Besides unloaded HS molecules, the molecular-size distribution of freshly formed metal species of HS (1.0 mg metal/g HS of Al(III), Cd(II), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), Zn(II), each) has been characterized by multistage UF as a function of pH-value, degree of loading and complexation time. Metal determinations as carried out by flame AAS, showed that considerable metal fractions in HS especially are present in molecules > 50 kD, which seemed to be rather acid-inert. With complexation times of < 2 days a transient shift of the molecular size distribution of both HS and their metal species (e.g., Al(III), Fe(III)) to higher values (> 10 kD) has been found. (orig.). With 9 figs., 2 tabs.

  11. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  12. Advances in management and utilization of invasive water hyacinth (Eichhornia crassipes) in aquatic ecosystems - a review.

    Science.gov (United States)

    Yan, Shao-Hua; Song, Wei; Guo, Jun-Yao

    2017-03-01

    The objective of this review is to provide a concise summary of literature in the Chinese language since late 1970s and focuses on recent development in global scenarios. This work will replenish the FAO summary of water hyacinth utilization from 1917 to 1979 and review ecological and socioeconomic impacts of the water hyacinth from 1980 to 2010. This review also discusses the debate on whether the growth of the water hyacinth is a problem, a challenge or an opportunity. Literature suggested that integrated technologies and good management may be an effective solution and the perception of water hyacinth could change from that of a notorious aquatic weed to a valuable resource, including its utilization as a biological agent for the application in bioremediation for removing excess nutrients from eutrophic water bodies at low cost. Key aspects on system integration and innovation may focus on low-cost and efficient equipment and the creation of value-added goods from water hyacinth biomass. In the socioeconomic and ecological domain of global development, all the successful and sustainable management inputs for the water hyacinth must generate some sort of social and economic benefit simultaneously, as well as benefiting the ecosystem. Potential challenges exist in linkages between the management of water hyacinth on the large scale to the sustainable development of agriculture based on recycling nutrients, bio-energy production or silage and feed production. Further research and development may focus on more detailed biology of water hyacinth related with its utilization, cost-benefit analysis of middle to large-scale application of the technologies and innovation of the equipment used for harvesting and dehydrating the plant.

  13. Impacts of invasive plants on carbon pools depend on both species' traits and local climate.

    Science.gov (United States)

    Martin, Philip A; Newton, Adrian C; Bullock, James M

    2016-12-30

    Invasive plants can alter ecosystem properties, leading to changes in the ecosystem services on which humans depend. However, generalizing about these effects is difficult because invasive plants represent a wide range of life forms, and invaded ecosystems differ in their plant communities and abiotic conditions. We hypothesize that differences in traits between the invader and native species can be used to predict impacts and so aid generalization. We further hypothesize that environmental conditions at invaded sites modify the effect of trait differences and so combine with traits to predict invasion impacts. To test these hypotheses, we used systematic review to compile data on changes in aboveground and soil carbon pools following non-native plant invasion from studies across the World. Maximum potential height (Hmax ) of each species was drawn from trait databases and other sources. We used meta-regression to assess which of invasive species' Hmax , differences in this height trait between native and invasive plants, and climatic water deficit, a measure of water stress, were good predictors of changes in carbon pools following invasion. We found that aboveground biomass in invaded ecosystems relative to uninvaded ones increased as the value of Hmax of invasive relative to native species increased, but that this effect was reduced in more water stressed ecosystems. Changes in soil carbon pools were also positively correlated with the relative Hmax of invasive species, but were not altered by water stress. This study is one of the first to show quantitatively that the impact of invasive species on an ecosystem may depend on differences in invasive and native species' traits, rather than solely the traits of invasive species. Our study is also the first to show that the influence of trait differences can be altered by climate. Further developing our understanding of the impacts of invasive species using this framework could help researchers to identify not only

  14. Differential allocation to photosynthetic and non-photosynthetic nitrogen fractions among native and invasive species.

    Directory of Open Access Journals (Sweden)

    Jennifer L Funk

    Full Text Available Invasive species are expected to cluster on the "high-return" end of the leaf economic spectrum, displaying leaf traits consistent with higher carbon assimilation relative to native species. Intra-leaf nitrogen (N allocation should support these physiological differences; however, N biochemistry has not been examined in more than a few invasive species. We measured 34 leaf traits including seven leaf N pools for five native and five invasive species from Hawaii under low irradiance to mimic the forest understory environment. We found several trait differences between native and invasive species. In particular, invasive species showed preferential N allocation to metabolism (amino acids rather than photosynthetic light reactions (membrane-bound protein by comparison with native species. The soluble protein concentration did not vary between groups. Under these low irradiance conditions, native species had higher light-saturated photosynthetic rates, possibly as a consequence of a greater investment in membrane-bound protein. Invasive species may succeed by employing a wide range of N allocation mechanisms, including higher amino acid production for fast growth under high irradiance or storage of N in leaves as soluble protein or amino acids.

  15. Nestucca Bay - Coastal Prairie Restoration and Invasive Species Control 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Control highly aggressive, non-native grasses and other invasive plants on 25 acres (Restoration Area 3/5) of former coastal headland prairie on Cannery Hill and...

  16. Columbia - Invasive Species Detection from Remote and Groundbased Mapping

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Columbia NWR has a number of invasive plants that have gone untreated due to lack of staff for detection and mapping. Volunteers can be used to map some areas where...

  17. Comparative Aquatic Toxicity of Gold Nanoparticles and Ionic Gold Using a Species Sensitivity Distribution Approach

    Directory of Open Access Journals (Sweden)

    Tarryn L. Botha

    2015-01-01

    Full Text Available Gold nanoparticles (nAu are used in drug delivery systems allowing for targeted cellular distribution. The effects of increased use and release of nanoparticles into the environment are not well known. A species sensitivity distribution (SSD allows for the ecotoxicological hazard assessment of a chemical based on single species toxicity tests. Aquatic toxicity needs to be related to particle characterization in order to understand the effects. The behaviour of nAu in the medium changed as the concentration increased. The toxic potential of ionic gold and nAu was expressed as a hazardous concentration where 5% of species will be harmed (HC5. The HC5 for nAu was much higher (42.78 mg/L compared to the ionic gold (2.44 mg/L. The differences between the hazard potentials of nAu and ionic gold were attributed to the nAu not releasing any Au ions into solution during the exposures and following an aggregation theory response. Exposures to ionic gold on the other hand followed a clear dose dependent response based on the concentration of the ionic metal. Although SSDs present an indication of the relative hazard potential of nanoparticles, the true worth can only be achieved once other nanoparticle characteristics and their behavior in the environment are also considered.

  18. Approach to determine the diversity of Legionella species by nested PCR-DGGE in aquatic environments

    Science.gov (United States)

    Huang, Wen-Chien; Tsai, Hsin-Chi; Tao, Chi-Wei; Chen, Jung-Sheng; Shih, Yi-Jia; Kao, Po-Min; Huang, Tung-Yi; Hsu, Bing-Mu

    2017-01-01

    In this study, we describe a nested PCR-DGGE strategy to detect Legionella communities from river water samples. The nearly full-length 16S rRNA gene was amplified using bacterial primer in the first step. After, the amplicons were employed as DNA templates in the second PCR using Legionella specific primer. The third round of gene amplification was conducted to gain PCR fragments apposite for DGGE analysis. Then the total numbers of amplified genes were observed in DGGE bands of products gained with primers specific for the diversity of Legionella species. The DGGE patterns are thus potential for a high-throughput preliminary determination of aquatic environmental Legionella species before sequencing. Comparative DNA sequence analysis of excised DGGE unique band patterns showed the identity of the Legionella community members, including a reference profile with two pathogenic species of Legionella strains. In addition, only members of Legionella pneumophila and uncultured Legionella sp. were detected. Development of three step nested PCR-DGGE tactic is seen as a useful method for studying the diversity of Legionella community. The method is rapid and provided sequence information for phylogenetic analysis. PMID:28166249

  19. Diversity of Aquatic Pseudomonas Species and Their Activity against the Fish Pathogenic Oomycete Saprolegnia.

    Science.gov (United States)

    Liu, Yiying; Rzeszutek, Elzbieta; van der Voort, Menno; Wu, Cheng-Hsuan; Thoen, Even; Skaar, Ida; Bulone, Vincent; Dorrestein, Pieter C; Raaijmakers, Jos M; de Bruijn, Irene

    2015-01-01

    Emerging fungal and oomycete pathogens are increasingly threatening animals and plants globally. Amongst oomycetes, Saprolegnia species adversely affect wild and cultivated populations of amphibians and fish, leading to substantial reductions in biodiversity and food productivity. With the ban of several chemical control measures, new sustainable methods are needed to mitigate Saprolegnia infections in aquaculture. Here, PhyloChip-based community analyses showed that the Pseudomonadales, particularly Pseudomonas species, represent one of the largest bacterial orders associated with salmon eggs from a commercial hatchery. Among the Pseudomonas species isolated from salmon eggs, significantly more biosurfactant producers were retrieved from healthy salmon eggs than from Saprolegnia-infected eggs. Subsequent in vivo activity bioassays showed that Pseudomonas isolate H6 significantly reduced salmon egg mortality caused by Saprolegnia diclina. Live colony mass spectrometry showed that strain H6 produces a viscosin-like lipopeptide surfactant. This biosurfactant inhibited growth of Saprolegnia in vitro, but no significant protection of salmon eggs against Saprolegniosis was observed. These results indicate that live inocula of aquatic Pseudomonas strains, instead of their bioactive compound, can provide new (micro)biological and sustainable means to mitigate oomycete diseases in aquaculture.

  20. The widespread collapse of an invasive species: Argentine ants (Linepithema humile) in New Zealand

    OpenAIRE

    2011-01-01

    Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9–15.3 years). Resident ant communities had recovered or partly re...

  1. Contrasting phenotypic plasticity in the photoprotective strategies of the invasive species Carpobrotus edulis and the coexisting native species Crithmum maritimum.

    Science.gov (United States)

    Fenollosa, Erola; Munné-Bosch, Sergi; Pintó-Marijuan, Marta

    2017-01-05

    Photoprotective strategies vary greatly within the plant kingdom and reflect a plant's physiological status and capacity to cope with environment variations. The plasticity and intensity of these responses may determine plant success. Invasive species are reported to show increased vigor to displace native species. Describing the mechanisms that confer such vigor is essential to understanding the success of invasive species. We performed an experiment whereby two species were monitored: Carpobrotus edulis, an aggressive invasive species in the Mediterranean basin, and Crithmum maritimum, a coexisting native species in the Cap de Creus Natural Park (NE Spain). We analyzed their photoprotective responses to seasonal environmental dynamics by comparing the capacity of the invader to respond to the local environmental stresses throughout the year. Our study analyses ecophysiological markers and photoprotective strategies to gain an insight into the success of invaders. We found that both species showed completely different but effective photoprotective strategies: In summer, C. edulis took special advantage of the xanthophyll cycle, whereas the success of C. maritimum in summer stemmed from morphological changes and β-carotene levels. Winter also presented differences between the species, as the native showed reduced Fv /Fm ratios. Our experimental design allowed us to introduce a new approach to compare phenotypic plasticity: the integrated phenotypic plasticity index (PPint ), defined as the maximum Euclidian distance between phenotypes, using a combination of different variables to describe them. This index revealed significantly greater phenotypic plasticity in the invasive species compared to the native species.

  2. Pre-adaptation or genetic shift after introduction in the invasive species Impatiens glandulifera?

    Science.gov (United States)

    Elst, Evelyne M.; Acharya, Kamal P.; Dar, Pervaiz A.; Reshi, Zafar A.; Tufto, Jarle; Nijs, Ivan; Graae, Bente J.

    2016-01-01

    Invasive exotic plants often grow fast, reproduce rapidly and display considerable phenotypic plasticity in their invasive range, which may be essential characteristics for successful invasion. However, it remains unclear whether these characteristics are already present in native populations (pre-adaptation hypothesis) or evolve after introduction (genetic shift hypothesis). To test these hypotheses we compared means and phenotypic plasticity of vegetative and reproductive traits between populations of Impatiens glandulifera collected from either the invasive (Norway) or native range (India). Seeds were sown and the resulting plants were exposed to different experimental environments in a glasshouse. We also tested whether trait means and reaction norms harbored genetic variation, as this may promote fitness in the novel environment. We did not find evidence that invasive populations of I. glandulifera grew more vigorously or produced more seeds than native populations. Phenotypic plasticity did not differ between the native and invasive range, except for the number of nodes which was more plastic in the invasive range. Genetic variation in the slope of reaction norms was absent, suggesting that the lack of change in phenotypic plasticity between native and invasive populations resulted from low genetic variation in phenotypic plasticity initially harbored by this species. Post-introduction evolution of traits thus probably did not boost the invasiveness of I. glandulifera. Instead, the species seems to be pre-adapted for invasion. We suggest that differences in habitat between the native and invasive range, more specifically the higher nutrient availability observed in the new environment, are the main factor driving the invasion of this species. Indeed, plants in the more nutrient-rich invasive range had greater seed mass, likely conferring a competitive advantage, while seed mass also responded strongly to nutrients in the glasshouse. Interactions between

  3. Checklist of invasive alien species in CSIR-NBRI Botanic Garden, Lucknow, India

    Directory of Open Access Journals (Sweden)

    Shilpi Singh

    2015-08-01

    Full Text Available The invasive alien species of CSIR-NBRI Botanic Garden are enumerated and their impact on the surrounding ecosystem are discussed. This study deals with the information on habit, nativity and family of plant species occurring in the area of study. A total of 103 invasive alien species under 86 genera and 36 families were recorded. Among these, the eudicotyledons represent 85 species, 69 genera and 32 families; monocotyledons represent 18 species, 17 genera and 4 families. In terms of nativity, species from Tropical America are the most dominant group with 34 species. In addition, based on life forms, herbs are dominant (88 species, followed by shrubs (8 species, climbers (4 species and trees (3 species.

  4. Ecology and space: A case study in mapping harmful invasive species

    Science.gov (United States)

    David T. Barnett,; Jarnevich, Catherine S.; Chong, Geneva W.; Stohlgren, Thomas J.; Sunil Kumar,; Holcombe, Tracy R.; Brunn, Stanley D.; Dodge, Martin

    2017-01-01

    The establishment and invasion of non-native plant species have the ability to alter the composition of native species and functioning of ecological systems with financial costs resulting from mitigation and loss of ecological services. Spatially documenting invasions has applications for management and theory, but the utility of maps is challenged by availability and uncertainty of data, and the reliability of extrapolating mapped data in time and space. The extent and resolution of projections also impact the ability to inform invasive species science and management. Early invasive species maps were coarse-grained representations that underscored the phenomena, but had limited capacity to direct management aside from development of watch lists for priorities for prevention and containment. Integrating mapped data sets with fine-resolution environmental variables in the context of species-distribution models allows a description of species-environment relationships and an understanding of how, why, and where invasions may occur. As with maps, the extent and resolution of models impact the resulting insight. Models of cheatgrass (Bromus tectorum) across a variety of spatial scales and grain result in divergent species-environment relationships. New data can improve models and efficiently direct further inventories. Mapping can target areas of greater model uncertainty or the bounds of modeled distribution to efficiently refine models and maps. This iterative process results in dynamic, living maps capable of describing the ongoing process of species invasions.

  5. Public attitude in the city of Belgrade towards invasive alien plant species

    Directory of Open Access Journals (Sweden)

    Tomićević Jelena

    2012-01-01

    Full Text Available Biological invasions are seen as a major threat to biodiversity at a global level, while the number of new invasions is increasing at an alarming rate. Raising the awareness of the public, academic world and policy makers about the dangers caused by invasive species, is essential for the creation of the support needed to implement and coordinate the policies necessary to address this problem. The aim of this study is to determine the level of local public awareness of the existence of these plant species, examine the public attitude towards alien invasive plant species and willingness to get involved in the prevention of their spreading. The survey was conducted in four nurseries on the territory of the City of Belgrade and the investigation dealt only with alien invasive woody plant species. Thirty customers were questioned in each of the four nurseries. The results show that local public is uninformed on the issue of invasive plant species. It is necessary to constantly and intensively raise their awareness of this issue, as well as the awareness of harmful consequences that may occur due to the uncontrolled spreading of alien invasive species. This refers not only to the population that visits the nurseries and buys the plants there and to those employed in plant production and selling, but also to the whole local public and decision makers.

  6. Modelling species invasions using thermal and trophic niche dynamics under climate change

    Directory of Open Access Journals (Sweden)

    Simone eLibralato

    2015-05-01

    Full Text Available Changing marine temperatures modify the distributional ranges of natural populations, but the success of invasion of new areas depends on local physical and ecological conditions. We explore the invasion by thermophilic species and their ecosystem effects by simulating a sea surface temperature increase using a trophodynamic model for the northern Adriatic Sea (NAS, in which thermal and trophic niches are explicitly represented for each thermophilic non-indigenous species and native species. The NAS acts as a cul-de-sac for local species, preventing a further poleward migration as a response to temperature rise. In this situation, model results showed that effects of warming and invasion produced complex, non-linear changes on biomasses but never resulted in a complete overturn of a group of native species and/or a bloom of invasive ones. Despite this, the diversity index stabilizes at increased values after simulating invasion, possibly indicating that in such enclosed systems the establishment of invasive species could represent enrichment in ecosystem structure. In addition, the absence of complete species substitution clearly showed the contribution of resident species towards increasing the resilience, i.e. the capability of the system to cope with invasion without changing substantially. Contrasting scenarios highlighted that changes in ecosystem primary production and species adaptation had secondary effects in ecosystem structure, while results for scenarios with different exploitation levels indicated that fishing can destabilize community structure in these change contexts, e.g. reducing community resilience. The results confirmed the importance of an ecological niche approach to analyze possible effects of invasion and highlighted the complexity of dynamics linked to temperature-driven species invasion’, in terms of both the predicted strength of impacts and the direction of biomass change.

  7. Utilizing next generation sequencing to characterize microsatellite loci in a tropical aquatic plant species Cryptocoryne cordata var. cordata (Araceae)

    DEFF Research Database (Denmark)

    Rosazlina, Rusly; Jacobsen, Niels; Ørgaard, Marian

    2015-01-01

    Abstract Cryptocoryne cordata var. cordata (2n = 34) is an aquatic plant species distributed from the southern part of Peninsular Thailand through the Malay Peninsula. It propagates both sexually and asexually via stolons. The current study is aimed at developing nuclear microsatellite markers...

  8. 76 FR 18575 - Nominations of New Members to the Invasive Species Advisory Committee (ISAC)

    Science.gov (United States)

    2011-04-04

    ... utilities, recreational users, tourism, etc.); representing sectors of the national economy whose routine..., providing for their control, and minimizing the economic, ecological, and human health impacts that invasive... to document, evaluate, and monitor impacts from invasive species; and facilitates establishment of...

  9. Invasive species: The categorization of wildlife in science, policy, and wildlife management

    NARCIS (Netherlands)

    Boonman-Berson, S.H.; Turnhout, E.; Tatenhove, van J.P.M.

    2014-01-01

    Species categories commonly used in nature conservation, such as protected, endangered, reintroduced,or invasive, are open to various interpretations that can result in diverging and sometimes serious con-sequences. This is vividly apparent with respect to invasiveness because the categorization of

  10. Proceedings of the SERI Biomass Program Principal Investigators' Review Meeting: Aquatic Species Program Reports; 23-25 June 1982, Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    1982-12-01

    The Aquatic Species Program (ASP) is concerned with how plant biomass that naturally occurs in wetland or submerged areas is utilized. Processes are being developed in this program to make use of those aquatic species, capitalizing on their inherent capacity for rapid growth as well as on their extraordinary chemical compositions.

  11. Effect of the Internet Commerce on Dispersal Modes of Invasive Alien Species

    Science.gov (United States)

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M. H.; Moroń, Dawid; Sutherland, William J.; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal. PMID:24932498

  12. Effect of the internet commerce on dispersal modes of invasive alien species.

    Science.gov (United States)

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M H; Moroń, Dawid; Sutherland, William J; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal.

  13. Monitoring of the aquatic environment by species accumulator of pollutants: a review

    Directory of Open Access Journals (Sweden)

    Oscar RAVERA

    2001-09-01

    Full Text Available This paper is a short review on the biomonitoring of aquatic environments by animal and plant species accumulators of toxic pollutants ("scavengers". This monitoring is based on the relationship between the pollutant concentration in the organism and that in its environment, and not on alterations produced by pollution on the biota. The latter is the basis of other types of biomonitoring, such as those based on the biotic and diversity indices and saprobic scale. The various aspects of monitoring by pollutant accumulators are illustrated; for example, the uptake and loss of pollutants, the "critical organs" and "tissues", the detoxification mechanisms and the most common factors (C.F., BAF, BSAF for establishing a connection between the pollutant concentration in the organism and that in its environment. Several examples of this monitoring on heavy metals, radioisotopes and organic micropollutants are reported. The advantages of this monitoring, the characteristics of the species to be used as bioaccumulators and some practical suggestions are listed. A close collaboration between the scientific teams working on the biomonitoring based on accumulator organisms and on the chemical monitoring is recommended from the scientific and economic point of view.

  14. Anti-biogram and resistogram profiling of Aeromonas species isolated from Malaysian aquatic sources

    Directory of Open Access Journals (Sweden)

    Olumide Adedokun Odeyemi

    2013-09-01

    Full Text Available Objective: To investigate antibiotics and heavy metals resistance profile of Aeromonas species isolated from Kuala Gula and Kuala Sepetang, Perak. Methods: Isolated Aeromonas species were subjected to 12 antibiotics: penicillin G 10 units, tetracycline 30 µg, novobiocin 5 µg, nitrofurantoin 100 µg, ampicillin 10 µg, chloramphenicol 10 µg, fluconazole 25 µg, gentamicin 10 µg, streptomycin 10 µg and 25 µg, kanamycin 30 µg, and vancomycin 30 µg and 5 heavy metals: MnSO4.H2O, Cr(NO3.9H2O, CuSO4, Pb(NO32, HgCl2. Results: Results from this study revealed that isolates from the two sources-displayed varied resistance. Isolates from Kuala Sepetang showed 91%, 66%, 61%, and 52% resistance to vancomycin, Novobiocin, streptomycin and gentamycin while Kuala Gula isolates showed 76%, 93%, 28% and 14% respectively. High rate of resistance was shown to be against lead (Pb, Chromium (Cr, copper (Cu and Manganese (Mn with minimum inhibitory concentration ranging from 2 560 µg/mL to >5 120 µg/mL. Low resistance to mercury was observed among isolates from Kuala Gula. Conclusions: This study showed that there was widespread of both heavy metals and antibiotics resistance among Aeromonas isolates from the two marine sources with isolates from Kuala Sepetang showing more resistance thereby posing danger to both aquatic animals and human health.

  15. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

    Directory of Open Access Journals (Sweden)

    Olumide A. Odeyemi

    2017-01-01

    Full Text Available This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13, bivalve (n = 10, sea cucumber (n = 16 and sea water (n = 14 and resistance to 12 antibiotics – Tetracycline (30 μg, Kanamycin (30 μg, Oxytetracycline (30 μg, Ampicillin (10 μg, Streptomycin (10 μg, Gentamicin (10 μg, Sulphamethoxazole (25 μg, Nalixidic acid (30 μg, Trimethoprim (1.25 μg, Novobiocin (5 μg, Penicilin (10 μg and Chloramphenicol (10 μg was tested. The results obtained from this study reveal multi drug resistance pattern among the isolates. All the isolates were completely resistant to Ampicillin, Novobiocin, Sulphamethoxazole and Trimethoprim, respectively but susceptible to Tetracycline (100%, Kanamycin (5.7%, Gentamicin (5.7% and Oxytetracycline (24.5%. Antibiotics phenotyping of the bacteria revealed 21 different phenotypes among the isolates.

  16. Anti-biogram and resistogram profiling of Aeromonas species isolated from Malaysian aquatic sources

    Institute of Scientific and Technical Information of China (English)

    Olumide Adedokun Odeyemi; Asmat Ahmad

    2013-01-01

    Objective: To investigate antibiotics and heavy metals resistance profile of Aeromonas species isolated from Kuala Gula and Kuala Sepetang, Perak. Methods: Isolated Aeromonas species were subjected to 12 antibiotics: penicillin G 10 units, tetracycline 30 µg, novobiocin 5 µg, nitrofurantoin 100 µg, ampicillin 10 µg, chloramphenicol 10 µg, fluconazole 25 µg, gentamicin 10 µg, streptomycin 10 µg and 25 µg, kanamycin 30 µg, and vancomycin 30 µg and 5 heavy metals: MnSO4.H2O, Cr(NO3).9H2O, CuSO4, Pb(NO3)2, HgCl2. Results: Results from this study revealed that isolates from the two sources-displayed varied resistance. Isolates from Kuala Sepetang showed 91%, 66%, 61%, and 52% resistance to vancomycin, Novobiocin, streptomycin and gentamycin while Kuala Gula isolates showed 76%, 93%, 28% and 14% respectively. High rate of resistance was shown to be against lead (Pb), Chromium (Cr), copper (Cu) and Manganese (Mn) with minimum inhibitory concentration ranging from 2 560 µg/mL to>5120 µg/mL. Low resistance to mercury was observed among isolates from Kuala Gula. Conclusions: This study showed that there was widespread of both heavy metals and antibiotics resistance among Aeromonas isolates from the two marine sources with isolates from Kuala Sepetang showing more resistance thereby posing danger to both aquatic animals and human health.

  17. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources.

    Science.gov (United States)

    Odeyemi, Olumide A; Ahmad, Asmat

    2017-01-01

    This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics - Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole (25 μg), Nalixidic acid (30 μg), Trimethoprim (1.25 μg), Novobiocin (5 μg), Penicilin (10 μg) and Chloramphenicol (10 μg) was tested. The results obtained from this study reveal multi drug resistance pattern among the isolates. All the isolates were completely resistant to Ampicillin, Novobiocin, Sulphamethoxazole and Trimethoprim, respectively but susceptible to Tetracycline (100%), Kanamycin (5.7%), Gentamicin (5.7%) and Oxytetracycline (24.5%). Antibiotics phenotyping of the bacteria revealed 21 different phenotypes among the isolates.

  18. Indirect effects of invasive species affecting the population structure of an ecosystem engineer

    NARCIS (Netherlands)

    Waser, A.M.; Splinter, W.; van der Meer, J.

    2015-01-01

    Species invasion is of increasing concern as non-native species often have negative impacts on ecosystems that they were introduced to. Invaders negatively affect the abundance of native species due to direct interactions like predation and competition. Additionally, invaders may benefit native biot

  19. Integrating conventional classifiers with a GIS expert system to increase the accuracy of invasive species mapping

    NARCIS (Netherlands)

    Masocha, M.; Skidmore, A.K.

    2011-01-01

    Mapping the cover of invasive species using remotely sensed data alone is challenging, because many invaders occur as mid-level canopy species or as subtle understorey species and therefore contribute little to the spectral signatures captured by passive remote sensing devices. In this study, two co

  20. Invasive mycosis due to species of Blastobotrys in immunocompromised patients with reduced susceptibility to antifungals

    NARCIS (Netherlands)

    Kumar, A.; Babu, R.; Bijulal, S.; Abraham, M.; Sasidharan, P.; Kathuria, S.; Sharma, C.; Meis, J.F.G.M.; Chowdhary, A.

    2014-01-01

    Cases of invasive mycosis due to Blastobotrys serpentis and B. proliferans identified by sequencing in a preterm patient and a rhabdomyosarcoma patient, respectively, are reported. Both species revealed elevated fluconazole and echinocandin MICs by the CLSI broth microdilution method. Additionally,

  1. The widespread collapse of an invasive species: Argentine ants (Linepithema humile) in New Zealand.

    Science.gov (United States)

    Cooling, Meghan; Hartley, Stephen; Sim, Dalice A; Lester, Philip J

    2012-06-23

    Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9-15.3 years). Resident ant communities had recovered or partly recovered after their collapse. Our models suggest that climate change will delay colony collapse, as increasing temperature and decreasing rainfall significantly increased their longevity, but only by a few years. Economic and environmental costs of invasive species may be small if populations collapse on their own accord.

  2. Mapping Habitat and Potential Distributions of Invasive Plant Species on USFWS National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Many invasive species ecologists prefer to use ecological niche models that rely on presence-only data and not make any assumptions on whether or not an absence...

  3. Tualatin River - Surveying, Monitoring and Combating Invasive Plant Species through Volunteers and Outreach

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Refuge, through a Cooperative Agreement with our Friends of the Tualatin River Refuge, proposes to build volunteer capacity for combating invasive species on the...

  4. 77 FR 37064 - Request for Nominations for the Invasive Species Advisory Committee; Extension of Submission...

    Science.gov (United States)

    2012-06-20

    ... international cooperation in addressing invasive species; facilitates the development of a coordinated network...; animal health protection; shipping, tourism, highways, and other transportation industries; international development and trade; public land access and management; lake, estuary, and coastal management;...

  5. [Montana MOYOCO Invasive Species Strike Team Final Report 2013] National Bison Range, Lee Metcalf ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  6. Mid-Columbia - Invasive Species Mapping and Management with Volunteers 2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Mid-Columbia River National Wildlife Refuge Complex proposed to survey, map, and ultimately control invasive species on Toppenish National Wildlife Refuge and...

  7. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] National Bison Range, Lee Metcalf ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  8. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Ninepipe National Wildlife Refuge, Lee Metcalf ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  9. Central European plant species from more productive habitats are more invasive at a global scale

    OpenAIRE

    Dostal, Petr; Dawson, Wayne; van Kleunen, Mark; Keser, Lidewij H.; Fischer, Markus

    2013-01-01

    Aim: Accumulating evidence indicates that species may be pre-adapted for invasionsuccess in new ranges. In the light of increasing global nutrient accumulation,an important candidate pre-adaptation for invasiveness is the ability to grow innutrient-rich habitats. Therefore we tested whether globally invasive species originating from Central Europe have come from more productive rather than lessproductive habitats. A further important candidate pre-adaptation for invasivenessis large niche wid...

  10. An invasive-native mammalian species replacement process captured by camera trap survey random encounter models

    OpenAIRE

    2016-01-01

    Camera traps are used to estimate densities or abundances using capture-recapture and, more recently, random encounter models (REMs). We deploy REMs to describe an invasive-native species replacement process, and to demonstrate their wider application beyond abundance estimation. The Irish hare Lepus timidus hibernicus is a high priority endemic of conservation concern. It is threatened by an expanding population of non-native, European hares L. europaeus, an invasive species of global import...

  11. Hypoxanthine-guanine phosphoribosyltransferase and inosine 5'-monophosphate dehydrogenase activities in three mammalian species: aquatic (Mirounga angustirostris), semi-aquatic (Lontra longicaudis annectens) and terrestrial (Sus scrofa).

    Science.gov (United States)

    Barjau Pérez-Milicua, Myrna; Zenteno-Savín, Tania; Crocker, Daniel E; Gallo-Reynoso, Juan P

    2015-01-01

    Aquatic and semiaquatic mammals have the capacity of breath hold (apnea) diving. Northern elephant seals (Mirounga angustirostris) have the ability to perform deep and long duration dives; during a routine dive, adults can hold their breath for 25 min. Neotropical river otters (Lontra longicaudis annectens) can hold their breath for about 30 s. Such periods of apnea may result in reduced oxygen concentration (hypoxia) and reduced blood supply (ischemia) to tissues. Production of adenosine 5'-triphosphate (ATP) requires oxygen, and most mammalian species, like the domestic pig (Sus scrofa), are not adapted to tolerate hypoxia and ischemia, conditions that result in ATP degradation. The objective of this study was to explore the differences in purine synthesis and recycling in erythrocytes and plasma of three mammalian species adapted to different environments: aquatic (northern elephant seal) (n = 11), semiaquatic (neotropical river otter) (n = 4), and terrestrial (domestic pig) (n = 11). Enzymatic activity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) was determined by spectrophotometry, and activity of inosine 5'-monophosphate dehydrogenase (IMPDH) and the concentration of hypoxanthine (HX), inosine 5'-monophosphate (IMP), adenosine 5'-monophosphate (AMP), adenosine 5'-diphosphate (ADP), ATP, guanosine 5'-diphosphate (GDP), guanosine 5'-triphosphate (GTP), and xanthosine 5'-monophosphate (XMP) were determined by high-performance liquid chromatography (HPLC). The activities of HGPRT and IMPDH and the concentration of HX, IMP, AMP, ADP, ATP, GTP, and XMP in erythrocytes of domestic pigs were higher than in erythrocytes of northern elephant seals and river otters. These results suggest that under basal conditions (no diving, sleep apnea or exercise), aquatic, and semiaquatic mammals have less purine mobilization than their terrestrial counterparts.

  12. Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

    Directory of Open Access Journals (Sweden)

    Merle Ööpik

    2013-06-01

    Full Text Available Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

  13. Will climate change promote future invasions?

    Science.gov (United States)

    Bellard, C.; Thuiller, W.; Leroy, B.; Genovesi, P.; Bakkenes, M.; Courchamp, F.

    2013-01-01

    Biological invasion is increasingly recognized as one of the greatest threats to biodiversity. Using ensemble forecasts from species distribution models to project future suitable areas of the “100 of the world’s worst invasive species” defined by the IUCN, we show that both climate and land use changes will likely cause drastic species range shifts. Looking at potential spatial aggregation of invasive species, we identify three future hotspots of invasion in Europe, northeastern North America, and Oceania. We also emphasize that some regions could lose a significant number of invasive alien species, creating opportunities for ecosystem restoration. From the list of 100, scenarios of potential range distributions show a consistent shrinking for invasive amphibians and birds, while for aquatic and terrestrial invertebrates distributions are projected to substantially increase in most cases. Given the harmful impacts these invasive species currently have on ecosystems, these species will likely dramatically influence the future of biodiversity. PMID:23913552

  14. Cabomba caroliniana A. Gray 1837: A new, alien and potentially invasive species in Serbia

    Directory of Open Access Journals (Sweden)

    Vukov Dragana

    2013-01-01

    Full Text Available During field studies of the vegetation in the canal network of the Hydro-System Danube-Tisa-Danube in Serbia, in 2008, 2011 and 2012, populations of Cabomba caroliniana A. Gray 1837 were recorded. Cabomba caroliniana was not previously recorded in the aquatic vegetation in Serbia. It is a popular aquarium plant native to South America (Brazil, Uruguay, Paraguay, and northeastern Argentina and, according to some authors, to southeastern United States. It was introduced into the rest of the USA, Canada, Australia, Asia (China, Malaysia, India, Japan, and in many regions of its new range it is considered an invasive and noxious aquatic weed. In Europe, it was found in the United Kingdom (introduced to England, Belgium, the Netherlands, and Hungary. Newly recorded populations in Serbia are restricted to the canals in Bačka. Populations are established only on two localities (Mali Stapar and Odžaci. [Projekat Ministarstva nauke Republike Srbije, br. III43002

  15. Exotic annual Bromus invasions: comparisons among species and ecoregions in the western United States

    Science.gov (United States)

    Brooks, Matthew L.; Brown, Cynthia S.; Chambers, Jeanne C.; D'Antonio, Carla M.; Keeley, Jon E.; Belnap, Jayne

    2016-01-01

    Exotic annual Bromus species are widely recognized for their potential to invade, dominate, and alter the structure and function of ecosystems. In this chapter, we summarize the invasion potential, ecosystem threats, and management strategies for different Bromus species within each of five ecoregions of the western United States. We characterize invasion potential and threats in terms of ecosystem resistance to Bromus invasion and ecosystem resilience to disturbance with an emphasis on the importance of fi re regimes. We also explain how soil temperature and moisture regimes can be linked to patterns of resistance and resilience and provide a conceptual framework that can be used to evaluate the relative potential for invasion and ecological impact of the dominant exotic annual Bromus species in the western United States.

  16. Federated or cached searches:Providing expected performance from multiple invasive species databases

    Institute of Scientific and Technical Information of China (English)

    Jim GRAHAM; Catherine S.JARNEVICH; Annie SIMPSON; Gregory J.NEWMAN; Thomas J.STOHLGREN

    2011-01-01

    Invasive species are a universal global problem,but the information to identify them,manage them,and prevent invasions is stored around the globe in a variety of formats.The Global Invasive Species Information Network is a consortium of organizations working toward providing seamless access to these disparate databases via the Internet.A distributed network of databases can be created using the Intemet and a standard web service protocol.There are two options to provide this integration.First,federated searches are being proposed to allow users to search "deep" web documents such as databases for invasive species.A second method is to create a cache of data from the databases for searching.We compare these two methods,and show that federated searches will not provide the performance and flexibility required from users and a central cache of the datum are required to improve performance.

  17. A case study of species assessment in invasion biology: the Village Weaverbird Ploceus cucullatus

    Directory of Open Access Journals (Sweden)

    Lahti, D. C.

    2003-01-01

    Full Text Available Application of recent insights gained in invasion biology to particular species may aid in addressing a central problem of the field, that of prediction of the dynamics of future introduction and invasion. The Village Weaverbird (Ploceus cucullatus is concluded to be a potential invader of concern in several regions, especially the Mediterranean, Caribbean, and southeastern United States. This conclusion is supported by the introduction and invasion history of the species, factors concluded in recent reviews and quantitative studies to correlate with introduction success or invasiveness in birds, the species' agricultural pest status in its current range, and a published rating system. A proactive stance is recommended since control efforts have met with little success, but certain characteristics of the Village Weaver may provide opportunities for management.

  18. Federated or cached searches: Providing expected performance from multiple invasive species databases

    Science.gov (United States)

    Graham, Jim; Jarnevich, Catherine S.; Simpson, Annie; Newman, Gregory J.; Stohlgren, Thomas J.

    2011-06-01

    Invasive species are a universal global problem, but the information to identify them, manage them, and prevent invasions is stored around the globe in a variety of formats. The Global Invasive Species Information Network is a consortium of organizations working toward providing seamless access to these disparate databases via the Internet. A distributed network of databases can be created using the Internet and a standard web service protocol. There are two options to provide this integration. First, federated searches are being proposed to allow users to search "deep" web documents such as databases for invasive species. A second method is to create a cache of data from the databases for searching. We compare these two methods, and show that federated searches will not provide the performance and flexibility required from users and a central cache of the datum are required to improve performance.

  19. NASA and USGS invest in invasive species modeling to evaluate habitat for Africanized Honey Bees

    Science.gov (United States)

    2009-01-01

    Invasive non-native species, such as plants, animals, and pathogens, have long been an interest to the U.S. Geological Survey (USGS) and NASA. Invasive species cause harm to our economy (around $120 B/year), the environment (e.g., replacing native biodiversity, forest pathogens negatively affecting carbon storage), and human health (e.g., plague, West Nile virus). Five years ago, the USGS and NASA formed a partnership to improve ecological forecasting capabilities for the early detection and containment of the highest priority invasive species. Scientists from NASA Goddard Space Flight Center (GSFC) and the Fort Collins Science Center developed a longterm strategy to integrate remote sensing capabilities, high-performance computing capabilities and new spatial modeling techniques to advance the science of ecological invasions [Schnase et al., 2002].

  20. Adherence to and invasion of human intestinal cells by Arcobacter species and their virulence genotypes.

    Science.gov (United States)

    Levican, Arturo; Alkeskas, Aldukali; Günter, Claudia; Forsythe, Stephen J; Figueras, María José

    2013-08-01

    The genus Arcobacter is composed of 17 species which have been isolated from various sources. Of particular interest are A. butzleri, A. cryaerophilus, and A. skirrowii, as these have been associated with human cases of diarrhea, the probable transmission routes being through the ingestion of contaminated drinking water and food. To date, only limited studies of virulence traits in this genus have been undertaken. The present study used 60 Arcobacter strains isolated from different sources, representing 16 of the 17 species of the genus, to investigate their ability to adhere to and invade the human intestinal cell line Caco-2. In addition, the presence of five putative virulence genes (ciaB, cadF, cj1349, hecA, and irgA) was screened for in these strains by PCR. All Arcobacter species except A. bivalviorum and Arcobacter sp. strain W63 adhered to Caco-2 cells, and most species (10/16) were invasive. The most invasive species were A. skirrowii, A. cryaerophilus, A. butzleri, and A. defluvii. All invasive strains were positive for ciaB (encoding a putative invasion protein). Other putative virulence genes were present in other species, i.e., A. butzleri (cadF, cj1349, irgA, and hecA), A. trophiarum (cj1349), A. ellisii (cj1349), and A. defluvii (irgA). No virulence genes were detected in strains which showed little or no invasion of Caco-2 cells. These results indicate that many Arcobacter species are potential pathogens of humans and animals.

  1. The spreading front of invasive species in favorable habitat or unfavorable habitat

    Science.gov (United States)

    Lei, Chengxia; Lin, Zhigui; Zhang, Qunying

    2014-07-01

    Spatial heterogeneity and habitat characteristic are shown to determine the asymptotic profile of the solution to a reaction-diffusion model with free boundary, which describes the moving front of the invasive species. A threshold value R0Fr(D,t) is introduced to determine the spreading and vanishing of the invasive species. We prove that if R0Fr(D,t0)⩾1 for some t0⩾0, the spreading must happen; while if R0Fr(D,0)species in the favorable habitat can establish itself if the diffusion is slow or the occupying habitat is large. In an unfavorable habitat, the species dies out if the initial value of the species is small. However, big initial number of the species is benefit for the species to survive. When the species spreads in the whole habitat, the asymptotic spreading speed is given. Some implications of these theoretical results are also discussed.

  2. The invasion of five alien species in the Delta do Parnaíba Environmental Protection Area, Northeastern Brazil.

    Science.gov (United States)

    Loebmann, Daniel; Mai, Ana Cecília G; Lee, James T

    2010-09-01

    Marine biological invasions have been regarded as one of the major causes of native biodiversity loss, with shipping and aquaculture being the leading contributors for the introductions of alien species in aquatic ecosystems. In the present study, five aquatic alien species (one mollusk, three crustaceans and one fish species) were detected during dives, shore searches and from the fisheries on the coast of the Delta do Parnaíba Environmental Protection Area, in the States of Piauí and Maranhão, Northeastern Brazil. The species were the bicolor purse-oyster Isognomon bicolor, the whiteleg shrimp Litopenaeus vannamei, the giant river prawn Macrobrachium rosenbergii, the Indo-Pacific swimming crab Charybdis hellerii and, the muzzled blenny Omobranchus punctatus. Ballast water (I. bicolor, C. hellerii, and O. punctatus) and aquaculture activities (L. vannamei and M. rosenbergii) in adjacent areas are the most likely vectors of introduction. All exotic species found have potential impact risks to the environment because they are able to compete against native species for resources (food and habitat). Isognomon bicolor share the same habitat and food items with the native bivalve species of mussels and barnacles. Litopenaeus vannamei share the same habitat and food items with the native penaeids such as the pinkspot shrimp Farfantepenaeus brasiliensis, the Southern brown shrimp Farfantepenaeus subtilis, and the Southern white shrimp Litopenaeus schmitti, and in the past few years L. vannamei was responsible for a viral epidemics in the cultivation tanks that could be transmitted to native penaeid shrimps. Charybdis hellerii is also able to cause impacts on the local fisheries as the species can decrease the populations of native portunid crabs which are commercialized in the studied region. Macrobrachium rosenbergii may be sharing natural resources with the Amazon River prawn Macrobrachium amazonicum. Omobranchus punctatus shares habit with the native redlip blenny

  3. Public Perception of Invasive Plant Species: Assessing the Impact of Workshop Activities to Promote Young Students' Awareness

    Science.gov (United States)

    Schreck Reis, Catarina; Marchante, Helia; Freitas, Helena; Marchante, Elizabete

    2013-01-01

    Invasive species are one of the main threats to biodiversity worldwide. Even though they are identified and recognized as such by the Portuguese law, the majority of the population is not yet aware of this problem. Aiming to increase awareness about biological invasions among young students, a workshop on Invasive Plant Species was organized at…

  4. Public Perception of Invasive Plant Species: Assessing the Impact of Workshop Activities to Promote Young Students' Awareness

    Science.gov (United States)

    Schreck Reis, Catarina; Marchante, Helia; Freitas, Helena; Marchante, Elizabete

    2013-01-01

    Invasive species are one of the main threats to biodiversity worldwide. Even though they are identified and recognized as such by the Portuguese law, the majority of the population is not yet aware of this problem. Aiming to increase awareness about biological invasions among young students, a workshop on Invasive Plant Species was organized at…

  5. Evaluation of Integrating the Invasive Species Forecasting System to Support National Park Service Decisions on Fire Management Activities and Invasive Plant Species Control

    Science.gov (United States)

    Ma, Peter; Morisette, T.; Rodman, Ann; McClure, Craig; Pedelty, Jeff; Benson, Nate; Paintner, Kara; Most, Neal; Ullah, Asad; Cai, Weijie; Rocca, Monique; Silverman, Joel; Schunase, John L.

    2007-01-01

    The USGS and NASA, in conjunction with Colorado State University, George Mason University and other partners, have developed the Invasive Species Forecasting System (ISFS), a flexible tool that capitalizes on NASA's remote sensing resource to produce dynamic habitat maps of invasive terrestrial plant species across the United States. In 2006 ISFS was adopted to generate predictive invasive habitat maps to benefit noxious plant and fire management teams in three major National Park systems: The Greater Yellowstone Area (Yellowstone / Grand Tetons National Parks), Sequoia and Kings Canyon National Park, and interior Alaskan (between Denali, Gates of The Arctic and Yukon-Charley). One of the objectives of this study is to explore how the ISFS enhances decision support apparatus in use by National Park management teams. The first step with each park system was to work closely with park managers to select top-priority invasive species. Specific species were chosen for each study area based on management priorities, availability of observational data, and their potential for invasion after fire disturbances. Once focal species were selected, sources of presence/absence data were collected from previous surveys for each species in and around the Parks. Using logistic regression to couple presence/absence points with environmental data layers, the first round of ISFS habitat suitability maps were generated for each National Park system and presented during park visits over the summer of 2006. This first engagement provided a demonstration of what the park service can expect from ISFS and initiated the ongoing dialog on how the parks can best utilized the system to enhance their decisions related to invasive species control. During the park visits it was discovered that separate "expert opinion" maps would provide a valuable baseline to compare against the ISFS model output. Opinion maps are a means of spatially representing qualitative knowledge into a quantitative two

  6. Housing is positively associated with invasive exotic plant species richness in New England, USA.

    Science.gov (United States)

    Gavier-Pizarro, Gregorio I; Radeloff, Volker C; Stewart, Susan I; Huebner, Cynthia D; Keuler, Nicholas S

    2010-10-01

    Understanding the factors related to invasive exotic species distributions at broad spatial scales has important theoretical and management implications, because biological invasions are detrimental to many ecosystem functions and processes. Housing development facilitates invasions by disturbing land cover, introducing nonnative landscaping plants, and facilitating dispersal of propagules along roads. To evaluate relationships between housing and the distribution of invasive exotic plants, we asked (1) how strongly is housing associated with the spatial distribution of invasive exotic plants compared to other anthropogenic and environmental factors; (2) what type of housing pattern is related to the richness of invasive exotic plants; and (3) do invasive plants represent ecological traits associated with specific housing patterns? Using two types of regression analysis (best subset analysis and hierarchical partitioning analysis), we found that invasive exotic plant richness was equally or more strongly related to housing variables than to other human (e.g., mean income and roads) and environmental (e.g., topography and forest cover) variables at the county level across New England. Richness of invasive exotic plants was positively related to area of wildland-urban interface (WUI), low-density residential areas, change in number of housing units between 1940 and 2000, mean income, plant productivity (NDVI), and altitudinal range and rainfall; it was negatively related to forest area and connectivity. Plant life history traits were not strongly related to housing patterns. We expect the number of invasive exotic plants to increase as a result of future housing growth and suggest that housing development be considered a primary factor in plans to manage and monitor invasive exotic plant species.

  7. Use of exotic species in afforestation and facilitation for the establishment of biological invasion

    Directory of Open Access Journals (Sweden)

    Juliano Ricardo Fabricante

    2017-02-01

    Full Text Available This study aimed to inventory the species used in landscaping the Campus of Agricultural Sciences of the Federal University of Paraíba, Areia, PB, Brazil and to rank them according to their origin and their invasive potential. Through walks throughout the study area (active search, we cataloged all the species used in local afforestation and classified them as native or exotic. Exotic plants were also classified as to their invasive potential. Altogether, we identified 76 species belonging to 67 genera and 25 families. Of these, only 26 species were native. The results of this study are worrisome because of the large number of exotic species used for planting at the study site (50 species, including known aggressive species: Artocarpus heterophyllus Lam., Azadirachta indica A. Juss. and Leucaena leucocephala (Lam. de Wit.

  8. Vegetation development following stream/river restoration: more natural fluvial dynamics and morphology, return of aquatic and riparian plant species?

    Science.gov (United States)

    Soons, M. B.

    2012-04-01

    After centuries of human interventions in stream/river dynamics and morphology aimed at optimizing landscapes for agricultural and industrial purposes, new insights have inspired water managers to try and combine stream and river ecosystem functions with the conservation of biodiversity. Around the world, aquatic and riparian species have declined strongly due to pollution, destruction and fragmentation of their habitat, so that biodiversity conservation initiatives primarily focus on habitat restoration. In the past decades many stream and river restoration projects have been carried out and often hydrological dynamics and morphology have been restored to a more natural state. However, the successful restoration of aquatic and riparian habitats very often failed to result in restoration of their biodiversity. This lack of success from a biodiversity conservation perspective is usually attributed to 'dispersal limitation', meaning that the habitat may be restored, but species fail to reach the site and re-colonize it. Especially re-colonization by aquatic and riparian plant species is important, as such species function as ecosystem engineers: their presence alters fluvial dynamics and morphology, generates additional habitat heterogeneity and provides habitat and food for animal species. Following minor disturbances, re-colonization is often possible through locally remaining populations, by seeds in the seed bank or by surviving plant fragments. However, following major disturbances, colonization and establishment from other source populations are necessary. This usually occurs through dispersal of seeds (and in more aquatic species also by dispersal of vegetative fragments) into the restored wetland area. As dispersal occurs predominantly over short distances and source populations of aquatic and riparian species may be lacking in the surroundings, dispersal may be a limiting factor in the development of aquatic and riparian vegetation at a restored site. But

  9. Hurricane activity and the large-scale pattern of spread of an invasive plant species.

    Science.gov (United States)

    Bhattarai, Ganesh P; Cronin, James T

    2014-01-01

    Disturbances are a primary facilitator of the growth and spread of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used historical aerial imagery to determine the growth rate of invasive Phragmites australis patches in wetlands along the Atlantic and Gulf Coasts of the United States. These were relatively undisturbed wetlands where P. australis had room for unrestricted growth. Over the past several decades, invasive P. australis stands expanded in size by 6-35% per year. Based on tropical storm and hurricane activity over that same time period, we found that the frequency of hurricane-force winds explained 81% of the variation in P. australis growth over this broad geographic range. The expansion of P. australis stands was strongly and positively correlated with hurricane frequency. In light of the many climatic models that predict an increase in the frequency and intensity of hurricanes over the next century, these results suggest a strong link between climate change and species invasion and a challenging future ahead for the management of invasive species.

  10. Analysis of the Trojan Y-Chromosome eradication strategy for an invasive species.

    Science.gov (United States)

    Wang, Xueying; Walton, Jay R; Parshad, Rana D; Storey, Katie; Boggess, May

    2014-06-01

    The Trojan Y-Chromosome (TYC) strategy, an autocidal genetic biocontrol method, has been proposed to eliminate invasive alien species. In this work, we analyze the dynamical system model of the TYC strategy, with the aim of studying the viability of the TYC eradication and control strategy of an invasive species. In particular, because the constant introduction of sex-reversed trojan females for all time is not possible in practice, there arises the question: What happens if this injection is stopped after some time? Can the invasive species recover? To answer that question, we perform a rigorous bifurcation analysis and study the basin of attraction of the recovery state and the extinction state in both the full model and a certain reduced model. In particular, we find a theoretical condition for the eradication strategy to work. Additionally, the consideration of an Allee effect and the possibility of a Turing instability are also studied in this work. Our results show that: (1) with the inclusion of an Allee effect, the number of the invasive females is not required to be very low when the introduction of the sex-reversed trojan females is stopped, and the remaining Trojan Y-Chromosome population is sufficient to induce extinction of the invasive females; (2) incorporating diffusive spatial spread does not produce a Turing instability, which would have suggested that the TYC eradication strategy might be only partially effective, leaving a patchy distribution of the invasive species.

  11. Analysis of the Trojan Y-Chromosome eradication strategy for an invasive species

    KAUST Repository

    Wang, Xueying

    2013-05-24

    The Trojan Y-Chromosome (TYC) strategy, an autocidal genetic biocontrol method, has been proposed to eliminate invasive alien species. In this work, we analyze the dynamical system model of the TYC strategy, with the aim of studying the viability of the TYC eradication and control strategy of an invasive species. In particular, because the constant introduction of sex-reversed trojan females for all time is not possible in practice, there arises the question: What happens if this injection is stopped after some time? Can the invasive species recover? To answer that question, we perform a rigorous bifurcation analysis and study the basin of attraction of the recovery state and the extinction state in both the full model and a certain reduced model. In particular, we find a theoretical condition for the eradication strategy to work. Additionally, the consideration of an Allee effect and the possibility of a Turing instability are also studied in this work. Our results show that: (1) with the inclusion of an Allee effect, the number of the invasive females is not required to be very low when the introduction of the sex-reversed trojan females is stopped, and the remaining Trojan Y-Chromosome population is sufficient to induce extinction of the invasive females; (2) incorporating diffusive spatial spread does not produce a Turing instability, which would have suggested that the TYC eradication strategy might be only partially effective, leaving a patchy distribution of the invasive species. © 2013 Springer-Verlag Berlin Heidelberg.

  12. Aquatic macrophytes of Itaipu Reservoir, Brazil: survey of species and ecological considerations

    Directory of Open Access Journals (Sweden)

    Sidinei Magela Thomaz

    1999-01-01

    Full Text Available In a survey of the aquatic macrophytes of the Itaipu Reservoir, we identified 62 taxa in 25 families and 42 genera. The highest number taxa was observed for the emergent macrophytes (40 taxa. Reduced fluctuation in water level, increased light penetration, and sediment enrichment by nutrients and organic matter following the formation of the reservoir favored the appearance of a species-rich community of submerged macrophytes (23% of the taxa identified. The aquatic macrophytes were found mainly near the mouths of the main tributaries of the reservoir, in shallow area of depth less than 2 meters. In addition to the shallow depth, the greater nutrient input from the tributaries and relative protection from wind explained this distribution. Among the species found, Egeria najas merits mention for its occurrence in all localities sampled, with biomass values varying between 98 and 186 gDW/m². Some potential nuisance species such as Eichhornia crassipes, Salvinia auriculata, and Pistia stratiotes also deserve attention, since they were also observed to be covering large areas of Itaipu Reservoir.Em um levantamento de macrófitas aquáticas realizado no reservatório de Itaipu foram identificados 62 táxons pertencentes a 25 famílias e 42 gêneros. O maior número de táxons foi representado pelas macrófitas emergentes (40 táxons. O surgimento de uma rica comunidade de espécies submersas (23% dos táxons identificados parece ter sido favorecido pelas alterações decorrentes da formação dor reservatório, tais como redução da flutuação dos níveis de água, aumento da penetração de luz e enriquecimento do sedimento em nutrientes e matéria orgânica. As macrófitas aquáticas foram registradas principalmente próximo à foz dos tributários do reservatório, em áreas rasas (profundidade inferior a 2 metros. Além da reduzida profundidade, o maior aporte de nutrientes associado à proteção do vento explicam essa distribuição. Entre

  13. Ecological impact of Prosopis species invasion in Turkwel riverine forest, Kenya

    NARCIS (Netherlands)

    Muturi, G.M.; Poorter, L.; Mohren, G.M.J.; Kigomo, B.N.

    2013-01-01

    The impact of Prosopis species invasion in the Turkwel riverine forest in Kenya was investigated under three contrasting: Acacia, Prosopis and Mixed species (Acacia and Prosopis) canopies. Variation amongst canopies was assessed through soil nutrients and physical properties, tree characteristics an

  14. Assessing and Managing the Current and Future Pest Risk from Water Hyacinth, (Eichhornia crassipes), an Invasive Aquatic Plant Threatening the Environment and Water Security

    Science.gov (United States)

    Brunel, Sarah

    2016-01-01

    Understanding and managing the biological invasion threats posed by aquatic plants under current and future climates is a growing challenge for biosecurity and land management agencies worldwide. Eichhornia crassipes is one of the world’s worst aquatic weeds. Presently, it threatens aquatic ecosystems, and hinders the management and delivery of freshwater services in both developed and developing parts of the world. A niche model was fitted using CLIMEX, to estimate the potential distribution of E. crassipes under historical and future climate scenarios. Under two future greenhouse gas emission scenarios for 2080 simulated with three Global Climate Models, the area with a favourable temperature regime appears set to shift polewards. The greatest potential for future range expansion lies in Europe. Elsewhere in the northern hemisphere temperature gradients are too steep for significant geographical range expansion under the climate scenarios explored here. In the Southern Hemisphere, the southern range boundary for E. crassipes is set to expand southwards in Argentina, Australia and New Zealand; under current climate conditions it is already able to invade the southern limits of Africa. The opportunity exists to prevent its spread into the islands of Tasmania in Australia and the South Island of New Zealand, both of which depend upon hydroelectric facilities that would be threatened by the presence of E. crassipes. In Europe, efforts to slow or stop the spread of E. crassipes will face the challenge of limited internal biosecurity capacity. The modelling technique demonstrated here is the first application of niche modelling for an aquatic weed under historical and projected future climates. It provides biosecurity agencies with a spatial tool to foresee and manage the emerging invasion threats in a manner that can be included in the international standard for pest risk assessments. It should also support more detailed local and regional management. PMID:27513336

  15. Non-use Economic Values for Little-Known Aquatic Species at Risk: Comparing Choice Experiment Results from Surveys Focused on Species, Guilds, and Ecosystems

    Science.gov (United States)

    Rudd, Murray A.; Andres, Sheri; Kilfoil, Mary

    2016-09-01

    Accounting for non-market economic values of biological diversity is important to fully assess the benefits of environmental policies and regulations. This study used three choice experiments (species-, guild-, and ecosystem-based surveys) in parallel to quantify non-use values for little-known aquatic species at risk in southern Ontario. Mean willingness-to-pay (WTP) ranged from 9.45 to 21.41 per listing status increment under Canada's Species at Risk Act for both named and unnamed little-known species. Given the broad range of valuable ecosystem services likely to accrue to residents from substantial increases in water quality and the rehabilitation of coastal wetlands, the difference in WTP between species- and ecosystem-based surveys seemed implausibly small. It appeared that naming species—the `iconization' of species in two of the three surveys—had an important effect on WTP. The results suggest that reasonable annual household-level WTP values for little-known aquatic species may be 10 to 25 per species or 10 to 20 per listing status increment. The results highlighted the utility of using parallel surveys to triangulate on non-use economic values for little-known species at risk.

  16. Rapid Prototyping of Hyperspectral Image Analysis Algorithms for Improved Invasive Species Decision Support Tools

    Science.gov (United States)

    Bruce, L. M.; Ball, J. E.; Evangilista, P.; Stohlgren, T. J.

    2006-12-01

    Nonnative invasive species adversely impact ecosystems, causing loss of native plant diversity, species extinction, and impairment of wildlife habitats. As a result, over the past decade federal and state agencies and nongovernmental organizations have begun to work more closely together to address the management of invasive species. In 2005, approximately 500M dollars was budgeted by U.S. Federal Agencies for the management of invasive species. Despite extensive expenditures, most of the methods used to detect and quantify the distribution of these invaders are ad hoc, at best. Likewise, decisions on the type of management techniques to be used or evaluation of the success of these methods are typically non-systematic. More efficient methods to detect or predict the occurrence of these species, as well as the incorporation of this knowledge into decision support systems, are greatly needed. In this project, rapid prototyping capabilities (RPC) are utilized for an invasive species application. More precisely, our recently developed analysis techniques for hyperspectral imagery are being prototyped for inclusion in the national Invasive Species Forecasting System (ISFS). The current ecological forecasting tools in ISFS will be compared to our hyperspectral-based invasives prediction algorithms to determine if/how the newer algorithms enhance the performance of ISFS. The PIs have researched the use of remotely sensed multispectral and hyperspectral reflectance data for the detection of invasive vegetative species. As a result, the PI has designed, implemented, and benchmarked various target detection systems that utilize remotely sensed data. These systems have been designed to make decisions based on a variety of remotely sensed data, including high spectral/spatial resolution hyperspectral signatures (1000's of spectral bands, such as those measured using ASD handheld devices), moderate spectral/spatial resolution hyperspectral images (100's of spectral bands, such

  17. Aquatic molluscs in high mountain lakes of the Eastern Alps (Austria): Species-environment relationships and specific colonization behaviour

    Institute of Scientific and Technical Information of China (English)

    STURM Robert

    2012-01-01

    Mountain lakes represent essential stages for aquatic species on their way colonizing habitats of more elevated regions.Despite extensive biological and chemical study,only little has been reported about the species number and density of freshwater molluscs in these waters.The article presented here elucidates the dispersal of aquatic gastropods and bivalves in 12 mountain lakes that are commonly situated in the Eastern Alps,Austria.Molluscs were recorded at 120 sample points,where a total of 13 species (8 gastropods and 5 bivalves) could be determined.Species distribution data as well as results from contemporarily conducted physico-chemical factor recording were subject to weighted average analysis.In addition,a global marginality coefficient indicating the particularity of a habitat inhabited by a focal species as well as a global tolerance coefficient expressing the width of a niche occupied by this species were computed.Species-environment relationships exhibited that species number and specific density decrease with increasing geographic altitude,declining water temperature,and decreasing amount of submerged vegetation.Whilst waters of the montane altitude level are partly charcterized by high number of mollusc species (>10),lakes of the subalpine altitude level commonly bear 1 or 2 species with <<1 ind./m2.As proposed by the results of statistics,9 of the 13 mollusc species are characterized by a pronounced behaviour as specialists with respect to most environmental factors.The four remaining species,Pisidium casertanum,Galba truncatula,Radix labiata,and Radix balthica,act as generalists which increases their pioneering role in the long-term occupation of the Central-alpine region.

  18. Association between Opuntia species invasion and changes in land-cover in the Mediterranean region

    OpenAIRE

    Vilà, Montserrat; Pino i Vilalta, Joan

    2003-01-01

    In Mediterranean regions, biological invasions pose a major threat to the conservation of native species and the integrity of ecosystems. In addition, changes in land-cover are a widespread phenomenon in Mediterranean regions, where an increase in urban areas and major changes from agricultural abandonment to shrub encroachment and afforestation are occurring. However, the link between biological invasions and changes in land-cover has scarcely been analyzed. We conducted a regional survey of...

  19. Colloquium paper: species invasions and extinction: the future of native biodiversity on islands.

    Science.gov (United States)

    Sax, Dov F; Gaines, Steven D

    2008-08-12

    Predation by exotic species has caused the extinction of many native animal species on islands, whereas competition from exotic plants has caused few native plant extinctions. Exotic plant addition to islands is highly nonrandom, with an almost perfect 1 to 1 match between the number of naturalized and native plant species on oceanic islands. Here, we evaluate several alternative implications of these findings. Does the consistency of increase in plant richness across islands imply that a saturation point in species richness has been reached? If not, should we expect total plant richness to continue to increase as new species are added? Finally, is the rarity of native plant extinctions to date a misleading measure of the impact of past invasions, one that hides an extinction debt that will be paid in the future? By analyzing historical records, we show that the number of naturalized plant species has increased linearly over time on many individual islands. Further, the mean ratio of naturalized to native plant species across islands has changed steadily for nearly two centuries. These patterns suggest that many more species will become naturalized on islands in the future. We also discuss how dynamics of invasion bear upon alternative saturation scenarios and the implications these scenarios have for the future retention or extinction of native plant species. Finally, we identify invasion-motivated research gaps (propagule pressure, time-lags to extinction, abundance shifts, and loss of area) that can aid in forecasting extinction and in developing a more comprehensive theory of species extinctions.

  20. Elaeagnus umbellata thunb. as the potential invasive species in Belgrade region

    Directory of Open Access Journals (Sweden)

    Skočajić Dragana

    2008-01-01

    Full Text Available It is known that invasive plant species, as the species which most often spread and suppress the native species, form stable populations and become dominant firstly by occupying the sites of urban areas, and later on by continuing their invasion to the neighbouring suburban and rural areas. This paper presents the research of biological and ecological characters of Elaeagnus umbellata Thunb., one of the potential invasive species. The phenological observation of this species yield abundance and periodicity and the biometric analysis of fruits and seeds point to a high quality of its generative reproductive material. The analysis of seed dormancy of this species in our conditions, as the significant factor of the control of potential invasiveness, shows its double dormancy and its elimination requires combined chemical treatments and several months of stratification. The study of mechanisms of autumn olive dormancy breaking (overcoming the reproductive barrier and seed dispersion (overcoming the dispersion barrier is very significant for the forecast of further dispersion of this species.

  1. Rapid species diagnosis for invasive candidiasis using mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Carine Marinach-Patrice

    Full Text Available BACKGROUND: Matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI TOF-MS allows the identification of most bacteria and an increasing number of fungi. The potential for the highest clinical benefit of such methods would be in severe acute infections that require prompt treatment adapted to the infecting species. Our objective was to determine whether yeasts could be identified directly from a positive blood culture, avoiding the 1-3 days subculture step currently required before any therapeutic adjustments can be made. METHODOLOGY/PRINCIPAL FINDINGS: Using human blood spiked with Candida albicans to simulate blood cultures, we optimized protocols to obtain MALDI TOF-MS fingerprints where signals from blood proteins are reduced. Simulated cultures elaborated using a set of 12 strains belonging to 6 different species were then tested. Quantifiable spectral differences in the 5000-7400 Da mass range allowed to discriminate between these species and to build a reference database. The validation of the method and the statistical approach to spectral analysis were conducted using individual simulated blood cultures of 36 additional strains (six for each species. Correct identification of the species of these strains was obtained. CONCLUSIONS/SIGNIFICANCE: Direct MALDI TOF-MS analysis of aliquots from positive blood cultures allowed rapid and accurate identification of the main Candida species, thus obviating the need for sub-culturing on specific media. Subsequent to this proof-of-principle demonstration, the method can be extended to other clinically relevant yeast species, and applied to an adequate number of clinical samples in order to establish its potential to improve antimicrobial management of patients with fungemia.

  2. Exploring new Routes for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with 31P NMR

    Science.gov (United States)

    Vestergren, Johan; Persson, Per; Sundman, Annelie; Ilstedt, Ulrik; Giesler, Reiner; Schleucher, Jürgen; Gröbner, Gerhard

    2014-05-01

    develop a new method to retrieve and characterize P components in water. By utilizing passive sampling with ion-exchange resin and subsequent analysis with solid state 31P MAS NMR we could identify various P-species extracted from the aquatic systems. By using this approach we can also study the dynamics of the absorption process at the resin as a function of P-species and temperature. This even enabled us to extract the fraction of bound versus free P as a function of temperature for different model P-components (manuscript in preparation). REFERENCES: Gilbert N. Nature 461 716-718 (2009) Vincent AG. et al., Biogeochemistry, 10.1007/s10533-011-9612-0 (2011). Vestergren J et al., Environ. Sci. Technol, 46, 3950-3956, (2012). Vincent AG et al., Plant Soil, 367, 149-162, (2013). Laudon H., et al., Water Resour. Res., 49, 7154-7158, (2013).

  3. Using the Maxent program for species distribution modelling to assess invasion risk

    Science.gov (United States)

    Jarnevich, Catherine S.; Young, Nicholas E.; Venette, R.C

    2015-01-01

    MAXENT is a software package used to relate known species occurrences to information describing the environment, such as climate, topography, anthropogenic features or soil data, and forecast the presence or absence of a species at unsampled locations. This particular method is one of the most popular species distribution modelling techniques because of its consistent strong predictive performance and its ease to implement. This chapter discusses the decisions and techniques needed to prepare a correlative climate matching model for the native range of an invasive alien species and use this model to predict the potential distribution of this species in a potentially invaded range (i.e. a novel environment) by using MAXENT for the Burmese python (Python molurus bivittatus) as a case study. The chapter discusses and demonstrates the challenges that are associated with this approach and examines the inherent limitations that come with using MAXENT to forecast distributions of invasive alien species.

  4. Non-lethal effects of an invasive species in the marine environment: the importance of early life-history stages.

    Science.gov (United States)

    Rius, Marc; Turon, Xavier; Marshall, Dustin J

    2009-04-01

    Studies examining the effects of invasive species have focussed traditionally on the direct/lethal effects of the invasive on the native community but there is a growing recognition that invasive species may also have non-lethal effects. In terrestrial systems, non-lethal effects of invasive species can disrupt early life-history phases (such as fertilisation, dispersal and subsequent establishment) of native species, but in the marine environment most studies focus on adult rather than early life-history stages. Here, we examine the potential for an introduced sessile marine invertebrate (Styela plicata) to exert both lethal and non-lethal effects on a native species (Microcosmus squamiger) across multiple early life-history stages. We determined whether sperm from the invasive species interfered with the fertilisation of eggs from the native species and found no effect. However, we did find strong effects of the invasive species on the post-fertilisation performance of the native species. The invasive species inhibited the settlement of native larvae and, in the field, the presence of the invasive species was associated with a ten-fold increase in the post-settlement mortality of the native species, as well as an initial reduction of growth in the native. Our results suggest that larvae of the native species avoid settling near the invasive species due to reduced post-settlement survival in its presence. Overall, we found that invasive species can have complex and pervasive effects (both lethal and non-lethal) across the early life-history stages of the native species, which are likely to result in its displacement and to facilitate further invasion.

  5. Multiple origins of pyrethroid insecticide resistance across the species complex of a nontarget aquatic crustacean, Hyalella azteca.

    Science.gov (United States)

    Weston, Donald P; Poynton, Helen C; Wellborn, Gary A; Lydy, Michael J; Blalock, Bonnie J; Sepulveda, Maria S; Colbourne, John K

    2013-10-08

    Use of pesticides can have substantial nonlethal impacts on nontarget species, including driving evolutionary change, often with unknown consequences for species, ecosystems, and society. Hyalella azteca, a species complex of North American freshwater amphipods, is widely used for toxicity testing of water and sediment and has frequently shown toxicity due to pyrethroid pesticides. We demonstrate that 10 populations, 3 from laboratory cultures and 7 from California water bodies, differed by at least 550-fold in sensitivity to pyrethroids. The populations sorted into four phylogenetic groups consistent with species-level divergence. By sequencing the primary pyrethroid target site, the voltage-gated sodium channel, we show that point mutations and their spread in natural populations were responsible for differences in pyrethroid sensitivity. At least one population had both mutant and WT alleles, suggesting ongoing evolution of resistance. Although nonresistant H. azteca were susceptible to the typical neurotoxic effects of pyrethroids, gene expression analysis suggests the mode of action in resistant H. azteca was not neurotoxicity but was oxidative stress sustained only at considerably higher pyrethroid concentrations. The finding that a nontarget aquatic species has acquired resistance to pesticides used only on terrestrial pests is troubling evidence of the impact of chronic pesticide transport from land-based applications into aquatic systems. Our findings have far-reaching implications for continued uncritical use of H. azteca as a principal species for monitoring and environmental policy decisions.

  6. Mapping invasive species and spectral mixture relationships with neotropical woody formations in southeastern Brazil

    Science.gov (United States)

    Amaral, Cibele H.; Roberts, Dar A.; Almeida, Teodoro I. R.; Souza Filho, Carlos R.

    2015-10-01

    Biological invasion substantially contributes to the increasing extinction rates of native vegetative species. The remote detection and mapping of invasive species is critical for environmental monitoring. This study aims to assess the performance of a Multiple Endmember Spectral Mixture Analysis (MESMA) applied to imaging spectroscopy data for mapping Dendrocalamus sp. (bamboo) and Pinus elliottii L. (slash pine), which are invasive plant species, in a Brazilian neotropical landscape within the tropical Brazilian savanna biome. The work also investigates the spectral mixture between these exotic species and the native woody formations, including woodland savanna, submontane and alluvial seasonal semideciduous forests (SSF). Visible to Shortwave Infrared (VSWIR) imaging spectroscopy data at one-meter spatial resolution were atmospherically corrected and subset into the different spectral ranges (VIS-NIR1: 530-919 nm; and NIR2-SWIR: 1141-2352 nm). The data were further normalized via continuum removal (CR). Multiple endmember selection methods, including Interactive Endmember Selection (IES), Endmember average root mean square error (EAR), Minimum average spectral angle (MASA) and Count-based (CoB) (collectively called EMC), were employed to create endmember libraries for the targeted vegetation classes. The performance of the MESMA was assessed at the pixel and crown scales. Statistically significant differences (α = 0.05) were observed between overall accuracies that were obtained at various spectral ranges. The infrared region (IR) was critical for detecting the vegetation classes using spectral data. The invasive species endmembers exhibited spectral patterns in the IR that were not observed in the native formations. Bamboo was characterized as having a high green vegetation (GV) fraction, lower non-photosynthetic vegetation (NPV) and a low shade fraction, while pine exhibited higher NPV and shade fractions. The invasive species showed a statistically

  7. Marine Invasive Species Management: Adapting in the Arctic

    DEFF Research Database (Denmark)

    Kaiser, Brooks

    2014-01-01

    The rapid pace of climate change and increased human disturbance of ecosystems in the Arctic is bringing urgency to concern over non-native species introductions and their potential threats to the marine environment and its economic productivity, where before environmental conditions served as a ...

  8. Invasive Alien Species of Terrestrial Vegetation of North-Eastern Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Sumit Srivastava

    2014-01-01

    Full Text Available The vegetational landscape of north-eastern Terai region at the foot hills of Central Himalayas is a mosaic of grassland, old-field, wasteland, and forest ecosystems. Like many other parts of the country, this region is also infested with alien intruders which not only interfere with the growth and production of food crops but also exercise adverse effects on the biodiversity of native species. The present study attempts to catalogue the invasive alien species of the terrestrial vegetation of north-eastern Uttar Pradesh especially with reference to their habit, taxonomic position, and nativity. A total of 1135 plant species within 580 genera under 119 families are so far known to occur in the region. Of these, only 149 species within 100 genera under 41 families have been found to be invasive aliens as evident from their center of origin, past history, nature of aggregation, and invasion observed under field conditions. About 80% of these invaders have been introduced from neotropics. Out of 173 invasive plants across India, this region shares 149 species, out of which 66% of species have come from Tropical America, 14% from African continent, and the rest from other countries. A better planning in the form of early identification and reporting of infestation and spread of noxious weeds is needed for their control.

  9. Attack of the invasive garden ant: aggression behaviour of Lasius neglectus (Hymenoptera: Formicidae) against native Lasius species in Spain

    DEFF Research Database (Denmark)

    Cremer, Sylvia; Ugelvig, Line Vej; Lommen, Suzanne T.E.;

    2006-01-01

    Invasive species often dramatically change native species communities by directly and indirectly out-competing na-tive species. We studied the direct interference abilities of the invasive garden ant, Lasius neglectus VAN LOON, BOOMSMA & ANDRÁSFALVY, 1990, by performing one-to-one aggression tests...

  10. Review on studies of Eupatorium adenophorum--an important invasive species in China

    Institute of Scientific and Technical Information of China (English)

    SUNXiao-yu; LUZhao-hua; SANGWei-guo

    2004-01-01

    Eupatorium adenophorum Spreng. was introduced in Yunnan Province of China around 1940. Since then it has been spreading rapidly, particularly in the southern and southwestern parts of China and caused serious economic loss. The biological research and integrated control on E. adenophorum were carried out from 1980's in Yunnan Province. Together with other 15 invasive external species, the weed has been listed in the White Paper by The State Environmental Protection Administration of China. This paper briefly reviews thestudies on natural distribution, biological character, ecological character, chemical component, hazard, potential application and the control of E. adenophorum. The research direction for this invasive external species in future was also discussed.

  11. Invasive species triggers a massive loss of ecosystem services through a trophic cascade.

    Science.gov (United States)

    Walsh, Jake R; Carpenter, Stephen R; Vander Zanden, M Jake

    2016-04-12

    Despite growing recognition of the importance of ecosystem services and the economic and ecological harm caused by invasive species, linkages between invasions, changes in ecosystem functioning, and in turn, provisioning of ecosystem services remain poorly documented and poorly understood. We evaluate the economic impacts of an invasion that cascaded through a food web to cause substantial declines in water clarity, a valued ecosystem service. The predatory zooplankton, the spiny water flea (Bythotrephes longimanus), invaded the Laurentian Great Lakes in the 1980s and has subsequently undergone secondary spread to inland lakes, including Lake Mendota (Wisconsin), in 2009. In Lake Mendota, Bythotrephes has reached unparalleled densities compared with in other lakes, decreasing biomass of the grazer Daphnia pulicaria and causing a decline in water clarity of nearly 1 m. Time series modeling revealed that the loss in water clarity, valued at US$140 million (US$640 per household), could be reversed by a 71% reduction in phosphorus loading. A phosphorus reduction of this magnitude is estimated to cost between US$86.5 million and US$163 million (US$430-US$810 per household). Estimates of the economic effects of Great Lakes invasive species may increase considerably if cases of secondary invasions into inland lakes, such as Lake Mendota, are included. Furthermore, such extreme cases of economic damages call for increased investment in the prevention and control of invasive species to better maximize the economic benefits of such programs. Our results highlight the need to more fully incorporate ecosystem services into our analysis of invasive species impacts, management, and public policy.

  12. The Physical and Biochemical Alteration of the Platte River by Phragmites australis, an Invasive Species of Wetland Grass

    Science.gov (United States)

    Mohr, R. C.; Krueger, R.; Triplett, L.; Michal, T.; Kettenring, K. M.

    2014-12-01

    Invasive species can have a profound impact on the ecosystems to which they are introduced. Beginning in 2003, the Platte River, Nebraska, USA, was invaded by an aggressive species of wetland grass, Phragmites australis. The invasion by Phragmites, in combination with river flow reductions due to agricultural irrigation, has drastically altered the character and morphology of the river. Once a braided and largely unvegetated river, the Platte had become densely colonized with vegetation by 2010. We measured some physical and biochemical characteristics of Platte River sediments to infer how that vegetation has changed the system. Specifically, we measured particle size, which is an indicator of flow velocity, and biogenic silica (BSi), which is a critical source of silicon for some aquatic organisms. Sediment was collected from areas of the riverbed that are unvegetated, and from areas that are occupied by Phragmites or native vegetation. Particle size was measured using a laser diffractometer to determine how much fine particle deposition was occurring. Biogenic silica (BSi) concentrations were measured using timed NaOH digestions and inductively coupled plasma mass spectrometry (ICP-MS). Our results indicate that stands of Phragmites in the Platte River cause more deposition of finer silt-sized particles than other parts of the river that are unvegetated or are occupied by native vegetation. Also, Phragmites increased the sequestration of BSi in the river sediments. These changes to the Platte reverberate beyond the river itself; by sequestering silica in sediments, Phragmites could be diminishing the supply of silica to estuaries and coastal oceans. Hypothesizing that the silica content of the Platte's water had been reduced by the arrival of Phragmites, we measured dissolved (DSi) and biogenic silica (BSi) concentrations of Platte water using ICP-MS to compare to existing data from the 1990s.

  13. Previous Land Use and Invasive Species Impacts on Long-term Afforestation Success

    Directory of Open Access Journals (Sweden)

    Joshua B. Nickelson

    2015-09-01

    Full Text Available The conversion of agricultural lands to forests has increased worldwide over the past few decades for multiple reasons including increasing forest connectivity and wildlife habitat. However, previous land cover and competing vegetation often impede afforestation. We established 219 plots in 29 Quercus plantations on four previous land cover types (LCT: Clover, Soybeans, Woody Brush, and Herbaceous Weeds. Plantations were located in Illinois, USA and were sampled 15–18 years after planting. Sampling data for all trees (planted and volunteer included species, diameter, and vine presence on the main bole of the tree. Free-to-grow status was recorded for all Quercus species and estimated cover of two invasive species, Elaeagnus umbellata and Lonicera japonica, was documented on each plot. There was a strong relationship between total tree density and invasive species cover across all sites. Stocking success was lower and E. umbellata cover was higher on Woody Brush sites compared to Clover and Soybean cover types. Additionally, significantly more free-to-grow Quercus saplings occurred in Clover and Soybean cover types compared to the Woody Brush sites. The results indicate that previous land cover plays a critical role in forest afforestation. Furthermore, while historically, volunteer tree species were thought to be detrimental to the development of planted species these results suggest that with the increasing prevalence of invasive species worldwide the role of volunteer species in afforestation should be reconsidered and silvicultural protocols adjusted accordingly.

  14. Detecting an elusive invasive species: a diagnostic PCR to detect Burmese python in Florida waters and an assessment of persistence of environmental DNA.

    Science.gov (United States)

    Piaggio, Antoinette J; Engeman, Richard M; Hopken, Matthew W; Humphrey, John S; Keacher, Kandy L; Bruce, William E; Avery, Michael L

    2014-03-01

    Recent studies have demonstrated that detection of environmental DNA (eDNA) from aquatic vertebrates in water bodies is possible. The Burmese python, Python bivittatus, is a semi-aquatic, invasive species in Florida where its elusive nature and cryptic coloration make its detection difficult. Our goal was to develop a diagnostic PCR to detect P. bivittatus from water-borne eDNA, which could assist managers in monitoring this invasive species. First, we used captive P. bivittatus to determine whether reptilian DNA could be isolated and amplified from water samples. We also evaluated the efficacy of two DNA isolation methods and two DNA extraction kits commonly used in eDNA preparation. A fragment of the mitochondrial cytochrome b gene from P. bivittatus was detected in all water samples isolated with the sodium acetate precipitate and the QIAamp DNA Micro Kit. Next, we designed P. bivittatus-specific primers and assessed the degradation rate of eDNA in water. Our primers did not amplify DNA from closely related species, and we found that P. bivittatus DNA was consistently detectable up to 96 h. Finally, we sampled water from six field sites in south Florida. Samples from five sites, where P. bivittatus has been observed, tested positive for eDNA. The final site was negative and had no prior documented evidence of P. bivittatus. This study shows P. bivittatus eDNA can be isolated from water samples; thus, this method is a new and promising technique for the management of invasive reptiles.

  15. Flow regime in a restored wetland determines trophic links and species composition in the aquatic macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    González-Ortegón, E., E-mail: quique.gonzalezortegon@andaluciajunta.es [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom); IFAPA Centro El Toruño, Camino Tiro de Pichón s/n, 11500 El Puerto de Santa María (Spain); Walton, M.E.M.; Moghaddam, B. [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom); Vilas, C.; Prieto, A. [IFAPA Centro El Toruño, Camino Tiro de Pichón s/n, 11500 El Puerto de Santa María (Spain); Kennedy, H.A. [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom); Pedro Cañavate, J. [IFAPA Centro El Toruño, Camino Tiro de Pichón s/n, 11500 El Puerto de Santa María (Spain); Le Vay, L. [School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB (United Kingdom)

    2015-01-15

    In a restored wetland (South of Spain), where different flow regimes control water exchange with the adjacent Guadalquivir estuary, the native Palaemon varians coexists with an exotic counterpart species Palaemon macrodactylus. This controlled m/acrocosm offers an excellent opportunity to investigate how the effects of water management, through different flow regimes, and the presence of a non-native species affect the aquatic community and the trophic niche (by gut contents and C-N isotopic composition) of the native shrimp Palaemon varians. We found that increased water exchange rate (5% day{sup −1} in mixed ponds vs. 0.1% day{sup −1} in extensive ponds) modified the aquatic community of this wetland; while extensive ponds are dominated by isopods and amphipods with low presence of P. macrodactylus, mixed ponds presented high biomass of mysids, corixids, copepods and both shrimp species. An estuarine origin of nutrients and primary production might explain seasonal and spatial differences found among ponds of this wetland. A combined analysis of gut contents and isotopic composition of the native and the exotic species showed that: (1) native P. varians is mainly omnivorous (2) while the non-native P. macrodactylus is more zooplanktivorous and (3) a dietary overlap occurred when both species coexist at mixed ponds where a higher water exchange and high abundance of mysids and copepods diversifies the native species' diet. Thus differences in the trophic ecology of both species are clearly explained by water management. This experimental study is a valuable tool for integrated management between river basin and wetlands since it allows quantification of wetland community changes in response to the flow regime. - Highlights: • Flow regimen is a major determinant of physicochemical habitat of a wetland. • Water exchanges wetland-estuary modify its aquatic community and trophic links. • Omnivory and physiological tolerance key in the resistance of a

  16. Species Distribution Model for Management of an Invasive Vine in Forestlands of Eastern Texas

    Directory of Open Access Journals (Sweden)

    Hsiao-Hsuan Wang

    2015-11-01

    Full Text Available Invasive plants decrease biodiversity, modify vegetation structure, and inhibit growth and reproduction of native species. Japanese honeysuckle (Lonicera japonica Thunb. is the most prevalent invasive vine in the forestlands of eastern Texas. Hence, we aimed to identify potential factors influencing the distribution of the species, quantify the relative importance of each factor, and test possible management strategies. We analyzed an extensive dataset collected as part of the Forest Inventory and Analysis Program of the United States Department of Agriculture (USDA Forest Service to quantify the range expansion of Japanese honeysuckle in the forestlands of eastern Texas from 2006 to 2011. We then identified potential factors influencing the likelihood of presence of Japanese honeysuckle using boosted regression trees. Our results indicated that the presence of Japanese honeysuckle on sampled plots almost doubled during this period (from 352 to 616 plots, spreading extensively, geographically. The probability of invasion was correlated with variables representing landscape conditions, climatic conditions, forest features, disturbance factors, and forest management activities. Habitats most at risk to invasion under current conditions occurred primarily in northeastern Texas, with a few invasion hotspots in the south. Estimated probabilities of invasion were reduced most by artificial site regeneration, with habitats most at risk again occurring primarily in northeastern Texas.

  17. Invasive species management restores a plant-pollinator mutualism in Hawaii

    Science.gov (United States)

    Hanna, Cause; Foote, David; Kremen, Claire

    2013-01-01

    1.The management and removal of invasive species may give rise to unanticipated changes in plant–pollinator mutualisms because they can alter the composition and functioning of plant–pollinator interactions in a variety of ways. To utilize a functional approach for invasive species management, we examined the restoration of plant–pollinator mutualisms following the large-scale removal of an invasive nectar thief and arthropod predator, Vespula pensylvanica. 2.We reduced V. pensylvanica populations in large plots managed over multiple years to examine the response of plant–pollinator mutualisms and the fruit production of a functionally important endemic Hawaiian tree species, Metrosideros polymorpha. To integrate knowledge of the invader's behaviour and the plant's mating system, we determined the efficacy of V. pensylvanica as a pollinator of M. polymorpha and quantified the dependence of M. polymorpha on animal pollination (e.g. level of self-compatibility and pollen limitation). 3.The reduction of V. pensylvanica in managed sites, when compared to unmanaged sites, resulted in a significant increase in the visitation rates of effective bee pollinators (e.g. introduced Apis mellifera and native Hylaeus spp.) and in the fruit production of M. polymorpha. 4.Apis mellifera, following the management of V. pensylvanica, appears to be acting as a substitute pollinator for M. polymorpha, replacing extinct or threatened bird and bee species in our study system. 5.Synthesis and applications. Fruit production of the native M. polymorpha was increased after management of the invasive pollinator predator V. pensylvanica; however, the main pollinators were no longer native but introduced. This research thus demonstrates the diverse impacts of introduced species on ecological function and the ambiguous role they play in restoration. We recommend incorporating ecological function and context into invasive species management as this approach may enable conservation

  18. Antibiotic susceptibility of body surface and gut micro flora of two aquatic leech species (Hirudinaria manillensis and Hirudinaria javanica) in Malaysia

    Institute of Scientific and Technical Information of China (English)

    Parimannan Sivachandran; Kasi Marimuthu; Manickam Ravichandran; Jesu Arockiaraj

    2013-01-01

    Objective: To elucidate the antibiotic susceptibility of body surface and gut associated microflora of two local aquatic leech species Hirudinaria manillensis and Hirudinaria javanica.Methods:Four commercially available antibiotics (doxycycline, chloramphenicol, tetracycline and ciprofloxacin) were used in this study. A total of 13 isolated gut and two surface micro flora from Hirudinaria manillensis and two gut and two surface micro flora from Hirudinaria javanica were tested for their antibiotic susceptibility. Results: Based on the susceptibility, it was observed that all the isolated bacteria were found to be susceptible to at least three of the antibiotics except Microbacterium resistens, Serratiamarcescens and Morganella morganii. This study also found that the bacterial species Bacillus fusiformis has displayed resistance against tetracycline and Tsukamurella inchonensis against chloramphenicol.Conclusions:Among all the antibiotics tested, ciprofloxacin was found to be the best bactericidal agent. The immersion of leeches in ciprofloxacin before the application to the patient may be beneficial to prevent invasive infection of the patient. Further study is needed to sterilize the live leech by immersion/oral mode of administration for the tested antibiotics.

  19. Antibiotic susceptibility of body surface and gut micro flora of two aquatic leech species (Hirudinaria manillensis and Hirudinaria javanica in Malaysia

    Directory of Open Access Journals (Sweden)

    Parimannan Sivachandran

    2013-08-01

    Full Text Available Objective: To elucidate the antibiotic susceptibility of body surface and gut associated microflora of two local aquatic leech species Hirudinaria manillensis and Hirudinaria javanica. Methods: Four commercially available antibiotics (doxycycline, chloramphenicol, tetracycline and ciprofloxacin were used in this study. A total of 13 isolated gut and two surface micro flora from Hirudinaria manillensis and two gut and two surface micro flora from Hirudinaria javanica were tested for their antibiotic susceptibility. Results: Based on the susceptibility, it was observed that all the isolated bacteria were found to be susceptible to at least three of the antibiotics except Microbacterium resistens, Serratia marcescens and Morganella morganii. This study also found that the bacterial species Bacillus fusiformis has displayed resistance against tetracycline and Tsukamurella inchonensis against chloramphenicol. Conclusions: Among all the antibiotics tested, ciprofloxacin was found to be the best bactericidal agent. The immersion of leeches in ciprofloxacin before the application to the patient may be beneficial to prevent invasive infection of the patient. Further study is needed to sterilize the live leech by immersion/oral mode of administration for the tested antibiotics.

  20. Analysis of Satellite and Airborne Imagery for Detection of Water Hyacinth and Other Invasive Floating Macrophytes and Tracking of Aquatic Weed Control Efficacy

    Science.gov (United States)

    Potter, Christopher

    2016-01-01

    Waterways of the Sacramento San Joaquin Delta have recently become infested with invasive aquatic weeds such as floating water hyacinth (Eichhoria crassipes) and water primrose (Ludwigia peploides). These invasive plants cause many negative impacts, including, but not limited to: the blocking of waterways for commercial shipping and boating; clogging of irrigation screens, pumps and canals; and degradation of biological habitat through shading. Zhang et al. (1997, Ecological Applications, 7(3), 1039-1053) used NASA Landsat satellite imagery together with field calibration measurements to map physical and biological processes within marshlands of the San Francisco Bay. Live green biomass (LGB) and related variables were correlated with a simple vegetation index ratio of red and near infra-red bands from Landsat images. More recently, the percent (water area) cover of water hyacinth plotted against estimated LGB of emergent aquatic vegetation in the Delta from September 2014 Landsat imagery showed an 80 percent overall accuracy. For the past two years, we have partnered with the U. S. Department of Agriculture (USDA) and the Department of Plant Sciences, University of California at Davis to conduct new validation surveys of water hyacinth and water primrose coverage and LGB in Delta waterways. A plan is underway to transfer decision support tools developed at NASA's Ames Research Center based on Landsat satellite images to improve Delta-wide integrated management of floating aquatic weeds, while reducing chemical control costs. The main end-user for this application project will be the Division of Boating and Waterways (DBW) of the California Department of Parks and Recreation, who has the responsibility for chemical control of water hyacinth in the Delta.

  1. Using Satellite Remote Sensing to Map Changes in Aquatic Invasive Plant Cover in the Sacramento-San Joaquin River Delta of California

    Science.gov (United States)

    Potter, Christopher

    2017-01-01

    Waterways of the Sacramento San Joaquin Delta have recently become infested with invasive aquatic weeds such as floating water hyacinth (Eichhoria crassipes) and water primrose (Ludwigia peploides). These invasive plants cause many negative impacts, including, but not limited to: the blocking of waterways for commercial shipping and boating; clogging of irrigation screens, pumps and canals; and degradation of biological habitat through shading. Zhang et al. (1997, Ecological Applications, 7(3), 1039-1053) used NASA Landsat satellite imagery together with field calibration measurements to map physical and biological processes within marshlands of the San Francisco Bay. Live green biomass (LGB) and related variables were correlated with a simple vegetation index ratio of red and near infra-red bands from Landsat images. More recently, the percent (water area) cover of water hyacinth plotted against estimated LGB of emergent aquatic vegetation in the Delta from September 2014 Landsat imagery showed a 80% overall accuracy. For the past two years, we have partnered with the U. S. Department of Agriculture (USDA) and the Department of Plant Sciences, University of California at Davis to conduct new validation surveys of water hyacinth and water primrose coverage and LGB in Delta waterways. A plan is underway to transfer decision support tools developed at NASA's Ames Research Center based on Landsat satellite images to improve Delta-wide integrated management of floating aquatic weeds, while reducing chemical control costs. The main end-user for this application project will be the Division of Boating and Waterways (DBW) of the California Department of Parks and Recreation, who has the responsibility for chemical control of water hyacinth in the Delta.

  2. Species diversity defends against the invasion of Nile tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Gu Dang E.

    2014-05-01

    Full Text Available Nile tilapia (Oreochromis niloticus is one of the most widely cultured species globally and has successfully colonized much of the world. Despite numerous studies of this exotic species, how differences in native communities mitigate the consequences of Nile tilapia invasion is unknown. Theory predicts that communities that are more diverse should be more resistant to exotic species, an effect that is referred to as “biotic resistance”, but these effects are spatially dependent and organism-specific. Field surveys and laboratory experiments were conducted to test the theory of “biotic resistance” and ascertain the relationship between native species richness and the invasion of Nile tilapia. In the field, we found that as native species richness increased, the biomass of Nile tilapia was significantly reduced. Consistent with results from the field, our manipulative experiment indicated that the growth of Nile tilapia was negatively related to native species richness. Thus, our study supports the theory of “biotic resistance” and suggests that species biodiversity represents an important defense against the invasion of Nile tilapia.

  3. Turbidity alters pre-mating social interactions between native and invasive stream fishes

    Science.gov (United States)

    Glotzbecker, Gregory J.; Ward, Jessica L.; Walters, David M.; Blum, Michael J.

    2015-01-01

    Environmental degradation can result in the loss of aquatic biodiversity if impairment promotes hybridisation between non-native and native species. Although aquatic biological invasions involving hybridisation have been attributed to elevated water turbidity, the extent to which impaired clarity influences reproductive isolation among non-native and native species is poorly understood.

  4. Abundance modelling of invasive and indigenous Culicoides species in Spain

    Directory of Open Access Journals (Sweden)

    Els Ducheyne

    2013-11-01

    Full Text Available In this paper we present a novel methodology applied in Spain to model spatial abundance patterns of potential vectors of disease at a medium spatial resolution of 5 x 5 km using a countrywide database with abundance data for five Culicoides species, random regression Forest modelling and a spatial dataset of ground measured and remotely sensed eco-climatic and environmental predictor variables. First the probability of occurrence was computed. In a second step a direct regression between the probability of occurrence and trap abundance was established to verify the linearity of the relationship. Finally the probability of occurrence was used in combination with the set of predictor variables to model abundance. In each case the variable importance of the predictors was used to biologically interpret results and to compare both model outputs, and model performance was assessed using four different accuracy measures. Results are shown for C. imicola, C. newsteadii, C. pulicaris group, C. punctatus and C. obsoletus group. In each case the probability of occurrence is a good predictor of abundance at the used spatial resolution of 5 x 5 km. In addition, the C. imicola and C. obsoletus group are highly driven by summer rainfall. The spatial pattern is inverse between the two species, indicating that the lower and upper thresholds are different. C. pulicaris group is mainly driven by temperature. The patterns for C. newsteadii and C. punctatus are less clear. It is concluded that the proposed methodology can be used as an input to transmission-infection-recovery (TIR models and R0 models. The methodology will become available to the general public as part of the VECMAPTM software.

  5. A simultaneous multiple species acute toxicity test comparing relative sensitivities of six aquatic organisms to HgCl{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    McCrary, J.E.; Heagler, M.G. [McNeese State Univ., Lake Charles, LA (United States). Dept. of Biological and Environmental Science

    1995-12-31

    In the last few years there has been concern in the scientific community about observed declines in some amphibian species. These population declines could be reflecting a global phenomenon due to a general class sensitivity or may be part of a natural cycle. The suggestion of an overall greater sensitivity of amphibians is not supported. Studies show that amphibians, as a class, are neither more or less susceptible than fish to environmental conditions. Mercury has been found to be one of the most toxic of the heavy metals introduced into amphibian breeding waters. Six aquatic species were simultaneously exposed in a comparative acute toxicity test with mercury chloride: three amphibians, Rana catesbeiana (bullfrog), R. clamitans (green frog), and R. sphenocephala (southern leopard frog, formally classified as R. utricularia); two fish, Gambusia affinis (mosquitofish) and Notemigonus crysoleucas (golden shiner); one aquatic aligochaete, Lumbriculus variegatus (aquatic earthworm). The five test concentrations used were 1.4, 3.9, 12.0, 110.0, and 487.0 {micro}g Hg/L respectively. Ten organisms per species were randomly placed into the six test tanks (control and five concentrations), each species in a separate chamber. The resultant LC50-96hr values produced the following rank order: R. sphenocephala, 6.59 {micro}g Hg/L; R. clamitans, 14.7 {micro}g Hg/L; N. crysoleucas, 16.75 {micro}g Hg/L; L. variegatus, 43.72,ug Hg/L; G. affinis, 52.62 {micro}g Hg/L; R. catesbeiana, 63.36 {micro}g Hg/L. No general organism class sensitivity trend, for amphibians, was developed from this data, contrary to the implicit suggestions of some researchers.

  6. Teaching citizen science skills online: Implications for invasive species training programs

    Science.gov (United States)

    Newman, G.; Crall, A.; Laituri, M.; Graham, J.; Stohlgren, T.; Moore, J.C.; Kodrich, K.; Holfelder, K.A.

    2010-01-01

    Citizen science programs are emerging as an efficient way to increase data collection and help monitor invasive species. Effective invasive species monitoring requires rigid data quality assurances if expensive control efforts are to be guided by volunteer data. To achieve data quality, effective online training is needed to improve field skills and reach large numbers of remote sentinel volunteers critical to early detection and rapid response. The authors evaluated the effectiveness of online static and multimedia tutorials to teach citizen science volunteers (n = 54) how to identify invasive plants; establish monitoring plots; measure percent cover; and use Global Positioning System (GPS) units. Participants trained using static and multimedia tutorials provided less (p Group, LLC.

  7. Improving invasive species management by integrating priorities and contributions of scientists and decision makers.

    Science.gov (United States)

    N'Guyen, Anouk; Hirsch, Philipp E; Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia

    2016-04-01

    Managing invasive species is a major challenge for society. In the case of newly established invaders, rapid action is key for a successful management. Here, we develop, describe and recommend a three-step transdisciplinary process (the "butterfly model") to rapidly initiate action for invasion management. In the framing of a case study, we present results from the first of these steps: assessing priorities and contributions of both scientists and decision makers. Both scientists and decision makers prioritise research on prevention. The available scientific knowledge contributions, however, are publications on impacts rather than prevention of the invasive species. The contribution of scientific knowledge does thus not reflect scientists' perception of what is essentially needed. We argue that a more objective assessment and transparent communication of not only decision makers' but also scientists' priorities is an essential basis for a successful cooperation. Our three-step model can help achieve objectivity via transdisciplinary communication.

  8. INVASIVESNET towards an International Association for Open Knowledge on Invasive Alien Species

    Science.gov (United States)

    Lucy, Frances E; Roy, Helen; Simpson, Annie; Carlton, James T.; Hanson, John Mark; Magellan, Kit; Campbell, Marnie L.; Costello, Mark J.; Pagad, Shyama; Hewitt, Chad L; McDonald, Justin; Cassey, Phillip; Thomaz, Sidinei M; Katsanevakis, Stelios; Zenetos, Argyro; Tricarico, Elena; Boggero, Angela; Groom, Quentin J; Adriaens, Tim; Vanderhoeven, Sonia; Torchin, Mark E.; Hufbauer, Ruth A.; Fuller, Pam; Carman, Mary R; Conn, David Bruce; Vitule, Jean R. S.; Canning-Clode, João; Galil, Bella S; Ojaveer, Henn; Bailey, Sarah A; Therriault, Thomas W; Claudi, Renata; Gazda, Anna; Dick, Jaimie T A; Caffrey, Joe; Witt, Arne; Kenis, Marc; Lehtiniemi, Maiju; Helmisaari, Harry; Panov, Vadim E

    2016-01-01

    In a world where invasive alien species (IAS) are recognised as one of the major threats to biodiversity, leading scientists from five continents have come together to propose the concept of developing an international association for open knowledge and open data on IAS—termed “INVASIVESNET”. This new association will facilitate greater understanding and improved management of invasive alien species (IAS) and biological invasions globally, by developing a sustainable network of networks for effective knowledge exchange. In addition to their inclusion in the CBD Strategic Plan for Biodiversity, the increasing ecological, social, cultural and economic impacts associated with IAS have driven the development of multiple legal instruments and policies. This increases the need for greater co-ordination, co-operation, and information exchange among scientists, management, the community of practice and the public.

  9. Historic Mining and Agriculture as Indicators of Occurrence and Abundance of Widespread Invasive Plant Species.

    Directory of Open Access Journals (Sweden)

    Kellen Calinger

    Full Text Available Anthropogenic disturbances often change ecological communities and provide opportunities for non-native species invasion. Understanding the impacts of disturbances on species invasion is therefore crucial for invasive species management. We used generalized linear mixed effects models to explore the influence of land-use history and distance to roads on the occurrence and abundance of two invasive plant species (Rosa multiflora and Berberis thunbergii in a 900-ha deciduous forest in the eastern U.S.A., the Powdermill Nature Reserve. Although much of the reserve has been continuously forested since at least 1939, aerial photos revealed a variety of land-uses since then including agriculture, mining, logging, and development. By 2008, both R. multiflora and B. thunbergii were widespread throughout the reserve (occurring in 24% and 13% of 4417 10-m diameter regularly-placed vegetation plots, respectively with occurrence and abundance of each varying significantly with land-use history. Rosa multiflora was more likely to occur in historically farmed, mined, logged or developed plots than in plots that remained forested, (log odds of 1.8 to 3.0; Berberis thunbergii was more likely to occur in plots with agricultural, mining, or logging history than in plots without disturbance (log odds of 1.4 to 2.1. Mining, logging, and agriculture increased the probability that R. multiflora had >10% cover while only past agriculture was related to cover of B. thunbergii. Proximity to roads was positively correlated with the occurrence of R. multiflora (a 0.26 increase in the log odds for every 1-m closer but not B. thunbergii, and roads had no impact on the abundance of either species. Our results indicated that a wide variety of disturbances may aid the introduction of invasive species into new habitats, while high-impact disturbances such as agriculture and mining increase the likelihood of high abundance post-introduction.

  10. Historic Mining and Agriculture as Indicators of Occurrence and Abundance of Widespread Invasive Plant Species.

    Science.gov (United States)

    Calinger, Kellen; Calhoon, Elisabeth; Chang, Hsiao-Chi; Whitacre, James; Wenzel, John; Comita, Liza; Queenborough, Simon

    2015-01-01

    Anthropogenic disturbances often change ecological communities and provide opportunities for non-native species invasion. Understanding the impacts of disturbances on species invasion is therefore crucial for invasive species management. We used generalized linear mixed effects models to explore the influence of land-use history and distance to roads on the occurrence and abundance of two invasive plant species (Rosa multiflora and Berberis thunbergii) in a 900-ha deciduous forest in the eastern U.S.A., the Powdermill Nature Reserve. Although much of the reserve has been continuously forested since at least 1939, aerial photos revealed a variety of land-uses since then including agriculture, mining, logging, and development. By 2008, both R. multiflora and B. thunbergii were widespread throughout the reserve (occurring in 24% and 13% of 4417 10-m diameter regularly-placed vegetation plots, respectively) with occurrence and abundance of each varying significantly with land-use history. Rosa multiflora was more likely to occur in historically farmed, mined, logged or developed plots than in plots that remained forested, (log odds of 1.8 to 3.0); Berberis thunbergii was more likely to occur in plots with agricultural, mining, or logging history than in plots without disturbance (log odds of 1.4 to 2.1). Mining, logging, and agriculture increased the probability that R. multiflora had >10% cover while only past agriculture was related to cover of B. thunbergii. Proximity to roads was positively correlated with the occurrence of R. multiflora (a 0.26 increase in the log odds for every 1-m closer) but not B. thunbergii, and roads had no impact on the abundance of either species. Our results indicated that a wide variety of disturbances may aid the introduction of invasive species into new habitats, while high-impact disturbances such as agriculture and mining increase the likelihood of high abundance post-introduction.

  11. Increase in quantity and quality of suitable areas for invasive species as climate changes.

    Science.gov (United States)

    Bertelsmeier, Cleo; Luque, Gloria M; Courchamp, Franck

    2013-12-01

    As climatically suitable range projections become increasingly used to assess distributions of species, we recommend systematic assessments of the quality of habitat in addition to the classical binary classification of habitat. We devised a method to assess occurrence probability, captured by a climatic suitability index, through which we could determine variations in the quality of potential habitat. This relative risk assessment circumvents the use of an arbitrary suitability threshold. We illustrated our method with 2 case studies on invasive ant species. We estimated invasion potential of the destroyer ant (Monomorium destructor) and the European fire ant (Myrmica rubra) on a global scale currently and by 2080 with climate change. We found that 21.1% of the world's landmass currently has a suitable climate for the destroyer ant and 16% has a suitable climate for European fire ant. Our climatic suitability index showed that both ant species would benefit from climate change, but in different ways. The size of the potential distribution increased by 35.8% for the destroyer ant. Meanwhile, the total area of potential distribution remained the same for the European fire ant (>0.05%), but the level of climatic suitability within this range increased greatly and led to an improvement in habitat quality (i.e., of invasive species' establishment likelihood). Either through quantity or quality of suitable areas, both invasive ant species are likely to increase the extent of their invasion in the future, following global climate change. Our results show that species may increase their range if either more areas become suitable or if the available areas present improved suitability. Studies in which an arbitrary suitability threshold was used may overlook changes in area quality within climatically suitable areas and as a result reach incorrect predictions. Incremento de la Cantidad y Calidad de Áreas Idóneas para Especies Invasoras a Medida que Cambia el Clima.

  12. Climate, invasive species and land use drive population dynamics of a cold-water specialist

    Science.gov (United States)

    Kovach, Ryan P.; Al-Chokhachy, Robert K.; Whited, Diane C.; Schmetterling, David A.; Dux, Andrew M; Muhlfeld, Clint C.

    2017-01-01

    Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stressors.We used long-term data from 92 populations of bull trout Salvelinus confluentus – one of North America's most cold-adapted fishes – to quantify additive and interactive effects of climate, invasive species and land use on population dynamics (abundance, variability and growth rate).Populations were generally depressed, more variable and declining where spawning and rearing stream habitat was limited, invasive species and land use were prevalent and stream temperatures were highest. Increasing stream temperature acted additively and independently, whereas land use and invasive species had additive and interactive effects (i.e. the impact of one stressor depended on exposure to the other stressor).Most (58%–78%) of the explained variation in population dynamics was attributed to the presence of invasive species, differences in life history and management actions in foraging habitats in rivers, lakes and reservoirs. Although invasive fishes had strong negative effects on populations in foraging habitats, proactive control programmes appeared to effectively temper their negative impact.Synthesis and applications. Long-term demographic data emphasize that climate warming will exacerbate imperilment of cold-water specialists like bull trout, yet other stressors – especially invasive fishes – are immediate threats that can be addressed by proactive management actions. Therefore, climate-adaptation strategies for freshwater biodiversity should consider existing abiotic and biotic stressors, some of which provide potential and realized opportunity for conservation

  13. Invasive mycosis due to species of Blastobotrys in immunocompromised patients with reduced susceptibility to antifungals.

    Science.gov (United States)

    Kumar, Anil; Babu, Rachana; Bijulal, Swapna; Abraham, Mohan; Sasidharan, P; Kathuria, Shallu; Sharma, Cheshta; Meis, Jacques F; Chowdhary, Anuradha

    2014-11-01

    Cases of invasive mycosis due to Blastobotrys serpentis and B. proliferans identified by sequencing in a preterm patient and a rhabdomyosarcoma patient, respectively, are reported. Both species revealed elevated fluconazole and echinocandin MICs by the CLSI broth microdilution method. Additionally, B. serpentis exhibited high amphotericin B MICs, thus posing serious therapeutic challenges.

  14. Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners

    NARCIS (Netherlands)

    Macel, M.; Vos, de R.C.H.; Jansen, J.J.; Putten, van der W.H.; Dam, van N.M.

    2014-01-01

    It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native co

  15. On the potential of plant species invasion influencing bio-geomorphologic landscape formation in salt marshes

    NARCIS (Netherlands)

    Schwarz, C.; Ysebaert, T.; Vandenbruwaene, W.; Temmerman, S.; Zhang, L.; Herman, P.

    2016-01-01

    Species invasions are known to change biotic and abiotic ecosystem characteristics such as community structure, cycling of materials and dynamics of rivers. However, their ability to alter interactions between biotic and abiotic ecosystem components, in particular bio-geomorphic feedbacks and the re

  16. On the potential of plant species invasion influencing bio-geomorphologic landscape formation in salt marshes

    NARCIS (Netherlands)

    Schwarz, Christian; Ysebaert, Tom; Vandenbruwaene, Wouter; Temmerman, Stijn; Zhang, Li Quan; Herman, Peter M.J.

    2016-01-01

    Species invasions are known to change biotic and abiotic ecosystem characteristics such as community structure, cycling of materials and dynamics of rivers. However, their ability to alter interactions between biotic and abiotic ecosystem components, in particular bio-geomorphic feedbacks and the

  17. Dynamic economic analysis on invasive species management: some policy implications of catchability.

    Science.gov (United States)

    Kotani, Koji; Kakinaka, Makoto; Matsuda, Hiroyuki

    2009-07-01

    The problem of controlling invasive species has emerged as a global issue. In response to invasive species threats, governments often propose eradication. This article challenges the eradication view by studying optimal strategies for controlling invasive species in a simple dynamic model. The analysis mainly focuses on deriving policy implications of catchability in a situation where a series of controlling actions incurs operational costs that derive from the fact that catchability depends on the current stock size of invasive species. We analytically demonstrate that the optimal policy changes drastically, depending on the sensitivity of catchability in response to a change in the stock size, as well as on the initial stock. If the sensitivity of catchability is sufficiently high, the constant escapement policy with some interior target level is optimal. In contrast, if the sensitivity of catchability is sufficiently low, there could exist a threshold of the initial stock which differentiates the optimal action between immediate eradication and giving-up without any control. In the intermediate range, immediate eradication, giving-up without any control, or more complex policies may be optimal. Numerical analysis is employed to present economic intuitions and insights in both analytically tractable and intractable cases.

  18. Missing the Boat on Invasive Alien Species: A Review of Post-Secondary Curricula in Canada

    Science.gov (United States)

    Smith, Andrea L.; Bazely, Dawn R.; Yan, Norman D.

    2011-01-01

    Invasive alien species (IAS) cause major environmental and economic damage worldwide, and also threaten human food security and health. The impacts of IAS are expected to rise with continued globalization, land use modification, and climate change. Developing effective strategies to deal with IAS requires a collaborative, interdisciplinary…

  19. Prediction of Prosopis species invasion in Kenya using geographical information system techniques

    NARCIS (Netherlands)

    Muturi, G.M.; Mohren, G.M.J.; Kimani, J.N.

    2010-01-01

    Tree species from Prosopis genus were widely planted for rehabilitation of degraded drylands of Kenya. However, they have invaded riverine ecosystems where they cause negative socio-economic and ecological impacts. GIS was used to estimate the reverine area threatened by Prosopis invasion in Kenya.

  20. The application of the European strategy on invasive alien species: an example with introduced squirrels

    OpenAIRE

    Sandro Bertolino; Piero Genovesi

    2005-01-01

    Abstract We assessed the cases of squirrel species already introduced into Italy inside the framework proposed by the European strategy on invasive alien species. We collected information on 9 introductions that originated 8 populations: 3 of grey squirrels (Sciurus carolinensis), 2 of Finlayson's squirrels (Callosciurus finlaysonii), and 3 of Siberian chip-munks (Eutamias sibiricus). Food opportunism...

  1. The aggressive invasion of exotic reptiles in Florida with a focus on prominent species: A review

    Institute of Scientific and Technical Information of China (English)

    Richard ENGEMAN; Elliott JACOBSON; Michael L. AVERY; Walter E. MESHAKA

    2011-01-01

    Florida,along with Hawaii,has among the two worst invasive species problems in the USA,and the state is especially susceptible to establishment by alien reptiles.Besides the large numbers of established non-native reptile species in Florida,many of these species present novel difficulties for management,or have other characteristics making effective management extremely challenging.Moreover,initiation of management action requires more than recognition by experts that a potentially harmful species has become established.It also requires the political will along with concomitant resources and appropriate personnel to develop effective methods and apply them.We review the situation in Florida,including assessment of risk for establishment,and we use a subset of prominent species to illustrate in more detail the array of invasive reptile species circumstances in Florida,including routes of introduction,impacts,and potential and implemented management actions.These examples not only highlight the severity of the invasive reptile problems in the state,but they also show the diversity in resolve and response towards them and the motivating factors [Current Zoology 57 (5):599-612,2011].

  2. Thermal ecological physiology of native and invasive frog species: do invaders perform better?

    Science.gov (United States)

    Cortes, Pablo A; Puschel, Hans; Acuña, Paz; Bartheld, José L; Bozinovic, Francisco

    2016-01-01

    Biological invasions are recognized as an important biotic component of global change that threatens the composition, structure and functioning of ecosystems, resulting in loss of biodiversity and displacement of native species. Although ecological characteristics facilitating the establishment and spread of non-native species are widely recognized, little is known about organismal attributes underlying invasion success. In this study, we tested the effect of thermal acclimation on thermal tolerance and locomotor performance in the invasive Xenopus laevis and the Chilean native Calyptocephalella gayi. In particular, the maximal righting performance (μMAX), optimal temperature (TO), lower (CTmin) and upper critical thermal limits (CTmax), thermal breadth (Tbr) and the area under the performance curve (AUC) were studied after 6 weeks acclimation to 10 and 20°C. We observed higher values of μmax and AUC in X. laevis in comparison to C. gayi. On the contrary, the invasive species showed lower values of CTmin in comparison to the native one. In contrast, CTmax, TO and Tbr showed no inter-specific differences. Moreover, we found that both species have the ability to acclimate their locomotor performance and lower thermal tolerance limit at low temperatures. Our results demonstrate that X. laevis is a better performer than C. gayi. Although there were differences in CTmin, the invasive and native frogs did not differ in their thermal tolerance. Interestingly, in both species the lower and upper critical thermal limits are beyond the minimal and maximal temperatures encountered in nature during the coldest and hottest month, respectively. Overall, our findings suggest that both X. laevis and C. gayi would be resilient to climate warming expectations in Chile.

  3. Does the order of invasive species removal matter? The case of the eagle and the pig.

    Directory of Open Access Journals (Sweden)

    Paul W Collins

    Full Text Available BACKGROUND: Invasive species are recognized as a primary driver of native species endangerment and their removal is often a key component of a conservation strategy. Removing invasive species is not always a straightforward task, however, especially when they interact with other species in complex ways to negatively influence native species. Because unintended consequences may arise if all invasive species cannot be removed simultaneously, the order of their removal is of paramount importance to ecological restoration. In the mid-1990s, three subspecies of the island fox Urocyon littoralis were driven to near extinction on the northern California Channel Islands owing to heightened predation by golden eagles Aquila chrysaetos. Eagles were lured to the islands by an abundant supply of feral pigs Sus scrofa and through the process of apparent competition pigs indirectly facilitated the decline in foxes. As a consequence, both pigs and eagles had to be removed to recover the critically endangered fox. Complete removal of pigs was problematic: removing pigs first could force eagles to concentrate on the remaining foxes, increasing their probability of extinction. Removing eagles first was difficult: eagles are not easily captured and lethal removal was politically distasteful. METHODOLOGY/PRINCIPAL FINDINGS: Using prey remains collected from eagle nests both before and after the eradication of pigs, we show that one pair of eagles that eluded capture did indeed focus more on foxes. These results support the premise that if the threat of eagle predation had not been mitigated prior to pig removal, fox extinction would have been a more likely outcome. CONCLUSIONS/SIGNIFICANCE: If complete eradication of all interacting invasive species is not possible, the order in which they are removed requires careful consideration. If overlooked, unexpected consequences may result that could impede restoration.

  4. Genetic networking of the Bemisia tabaci cryptic species complex reveals pattern of biological invasions.

    Directory of Open Access Journals (Sweden)

    Paul De Barro

    Full Text Available BACKGROUND: A challenge within the context of cryptic species is the delimitation of individual species within the complex. Statistical parsimony network analytics offers the opportunity to explore limits in situations where there are insufficient species-specific morphological characters to separate taxa. The results also enable us to explore the spread in taxa that have invaded globally. METHODOLOGY/PRINCIPAL FINDINGS: Using a 657 bp portion of mitochondrial cytochrome oxidase 1 from 352 unique haplotypes belonging to the Bemisia tabaci cryptic species complex, the analysis revealed 28 networks plus 7 unconnected individual haplotypes. Of the networks, 24 corresponded to the putative species identified using the rule set devised by Dinsdale et al. (2010. Only two species proposed in Dinsdale et al. (2010 departed substantially from the structure suggested by the analysis. The analysis of the two invasive members of the complex, Mediterranean (MED and Middle East - Asia Minor 1 (MEAM1, showed that in both cases only a small number of haplotypes represent the majority that have spread beyond the home range; one MEAM1 and three MED haplotypes account for >80% of the GenBank records. Israel is a possible source of the globally invasive MEAM1 whereas MED has two possible sources. The first is the eastern Mediterranean which has invaded only the USA, primarily Florida and to a lesser extent California. The second are western Mediterranean haplotypes that have spread to the USA, Asia and South America. The structure for MED supports two home range distributions, a Sub-Saharan range and a Mediterranean range. The MEAM1 network supports the Middle East - Asia Minor region. CONCLUSION/SIGNIFICANCE: The network analyses show a high level of congruence with the species identified in a previous phylogenetic analysis. The analysis of the two globally invasive members of the complex support the view that global invasion often involve very small portions of

  5. Aquatic macrophyte diversity of the Pantanal wetland and upper basin

    Directory of Open Access Journals (Sweden)

    VJ. Pott

    Full Text Available This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz Morrone & Zuloaga.

  6. Aquatic macrophyte diversity of the Pantanal wetland and upper basin.

    Science.gov (United States)

    Pott, V J; Pott, A; Lima, L C P; Moreira, S N; Oliveira, A K M

    2011-04-01

    This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas) and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga.

  7. Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Houserova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic)]. E-mail: kuban@mendelu.cz; Kracmar, Stanislav [Department of Animal Nutrition, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Sitko, Jilji [Commenius Museum, Moravian Ornithological Station, Horni nam. 1, Prerov CZ-751 52 (Czech Republic)

    2007-01-15

    Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg{sup 2+}) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F {sub 4.6} = 56.71, P < 10{sup -5}). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed.

  8. Research Progress on Invasion Mechanism of Alien Invasive Species%外来物种入侵机制的研究进展

    Institute of Scientific and Technical Information of China (English)

    张巧; 郝建锋

    2011-01-01

    To make foundation for further study of alien plant invasion and fundamentally control alien plant invasion, in this paper the invasion status of alien plants in China was generalized, the process and mechanisms of biological invasion were analyzed and prevention and control measures were proposed which is of great significance to prevention of malignant alien invasive species invasion.%为了从根本上有效控制外来植物的入侵,为外来植物入侵的深入研究提供参考,综述了我国外来物种入侵现状,分析外来物种入侵过程及入侵机制,提出对入侵物种的预防和控制措施,对于防治恶性外来入侵物种有重要意义.

  9. Selenium exposure results in reduced reproduction in an invasive ant species and altered competitive behavior for a native ant species.

    Science.gov (United States)

    De La Riva, Deborah G; Trumble, John T

    2016-06-01

    Competitive ability and numerical dominance are important factors contributing to the ability of invasive ant species to establish and expand their ranges in new habitats. However, few studies have investigated the impact of environmental contamination on competitive behavior in ants as a potential factor influencing dynamics between invasive and native ant species. Here we investigated the widespread contaminant selenium to investigate its potential influence on invasion by the exotic Argentine ant, Linepithema humile, through effects on reproduction and competitive behavior. For the fecundity experiment, treatments were provided to Argentine ant colonies via to sugar water solutions containing one of three concentrations of selenium (0, 5 and 10 μg Se mL(-1)) that fall within the range found in soil and plants growing in contaminated areas. Competition experiments included both the Argentine ant and the native Dorymyrmex bicolor to determine the impact of selenium exposure (0 or 15 μg Se mL(-1)) on exploitation- and interference-competition between ant species. The results of the fecundity experiment revealed that selenium negatively impacted queen survival and brood production of Argentine ants. Viability of the developing brood was also affected in that offspring reached adulthood only in colonies that were not given selenium, whereas those in treated colonies died in their larval stages. Selenium exposure did not alter direct competitive behaviors for either species, but selenium exposure contributed to an increased bait discovery time for D. bicolor. Our results suggest that environmental toxins may not only pose problems for native ant species, but may also serve as a potential obstacle for establishment among exotic species.

  10. Is there a need for a more explicit accounting of invasive alien species under the Water Framework Directive?

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    Jochen Vandekerkhove

    2013-01-01

    Full Text Available Through ratification of the Water Framework Directive (WFD, EU Member States committed themselves to a pressure-based assessment ofthe ecological status of their water bodies. Invasive alien species (IAS constitute a major pressure in many aquatic ecosystems, yet are notexplicitly accounted for by the majority of WFD assessment methods. Most Member States argue that no explicit assessment of IAS isrequired, assuming that significant IAS pressures will affect the WFD biological quality elements (BQEs, and be detected by generic WFDstatus assessments. We tested this assumption for a selection of country-by-surface-water category combinations, covering nearly 40,000water bodies. For each of the combinations, the pressure by high-impact IAS is higher in water bodies with ecological status varying from bad to moderate than in water bodies in good or high ecological status. Most high-impact IAS show strong associations with low status class categories. Of the 17 most frequently occurring high-impact IAS, only Mustela vison (Schreber, 1777 and Potamopyrgus antipodarum(Gray, 1853 are disproportionately frequent in high status water bodies. The sensitivity of WFD methods varies across BQEs, withmacrophyte-based methods showing a consistently high sensitivity to IAS pressures. However, significant pressures are observed in anumber of high status water bodies. This points to a need for further optimization of existing methods so that they address the full range of pressures exerted by IAS.

  11. Comparative sensitivity of aquatic invertebrate and vertebrate species to wastewater from an operational coal mine in central Queensland, Australia.

    Science.gov (United States)

    Lanctôt, C; Wilson, S P; Fabbro, L; Leusch, F D L; Melvin, S D

    2016-07-01

    Coal excavation and refinement processes generate substantial volumes of contaminated effluent that may be detrimental to aquatic ecosystems. As such, understanding the impacts of coal mine water releases on aquatic animals and ecosystems is essential for effectively managing and protecting neighboring environments. Such information will ultimately be applied towards developing ongoing monitoring strategies that are protective of native wildlife. Despite intensive mining operations in Australia, few studies have documented toxicity associated with coal mine wastewater (CMW) on native species. To address existing knowledge gaps, we investigated acute toxicity (48-96h) using eight native invertebrate species and sub-chronic effects (2 week) using three vertebrate species following exposure to wastewater from two dams (CMW1 and CMW2) located at an open-cut coal mine licensed to discharge into the Fitzroy catchment (Queensland, Australia). Wastewater from these sites is characterized by elevated conductivity, pH, sulfates as well as relatively high total and dissolved metal(loid)s (including As, Al, B, Cu, Mn, Ni, Se and Zn). Acute exposures revealed cladocerans (Daphnia carinata) and planarians (Dugesia sp.) to be the most sensitive species, exhibiting significant mortality after 48 and 96h exposure to CMW2, respectively. Neither wastewater was found to elicit acute toxicity in vertebrates, but a range of sub-lethal morphological effects were observed following the sub-chronic exposures. The overall response pattern was characterized by decreased condition factor and hepatosomatic index in the fish Hypseleotris compressa and Pseudomugil signifier, and in Limnodynastes peronii tadpoles. Tadpoles were generally more sensitive compared to the two fish species. Differences in responses were observed amongst CMW1 and CMW2, which likely relates to differences in physico-chemical properties between sites. Our results have identified several candidate vertebrate and

  12. Freshwater Aquatic Nuisance Species Impacts and Management Costs and Benefits at Federal Water Resources Projects

    Science.gov (United States)

    2006-09-01

    the Mayan cichlid (Cichlasoma urophthalmus) and black acara (Cichlasoma bimaculatum) from tropical America. A large predator of the same family, the...plant management. IMPLICATION FOR CORPS CIVIL WORKS: Recent analyses by Rockwell (2003) and Lovell and Stone (2005) emphasize the shortage of...of the Army (2004)). In 2003, the Corps Civil Works program reported about $5 million in aquatic plant control costs (USACE 2004). Over 77 percent of

  13. Management of invasive plant species in Nigeria through economic exploitation: lessons from other countries

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    Folaranmi Dapo Babalola

    2012-12-01

    Full Text Available Invasive alien species, once they made entry into a region or country, often become difficult to eradicate and it appears that they have cometo stay. Worse still, their adverse effects on the native biodiversity are enormous and they are considered ecologically harmful. Agriculturaland economic losses to invasive species are comparatively high. Mechanical control is expensive and difficult in some terrains; chemicalcontrol is also expensive, requires constant application and has its environmental implications, while biological control is mirred with mixedfailures and successes. This paper reviewed that economic exploitation of some notorious invasive species in other countries – such asSudan, Ethiopia, India, Senegal, Mali and the Gambia – and how this had helped reduce the spread of these invasives and at the same time,became source of income to the poor people. It is believed that adopting this concept in Nigeria will create incentives for harvesting invasivespecies with more commitment, while it is an indirect way of controlling them. Furthermore, harvesting could be labour intensive, thuscreating jobs for people, while it provides additional means of income for rural people, which is a key adaptation strategy for climate change.

  14. Restoration versus invasive species: Bigheaded carps’ use of a rehabilitated backwater

    Science.gov (United States)

    Coulter, Alison A; Schultz, Douglas; Tristano, Elizabeth; Brey, Marybeth; Garvey, James E.

    2017-01-01

    Knowledge of how invasive species use invaded habitats can aid in developing management practices to exclude them. Swan Lake, a 1100-ha Illinois River (USA) backwater, was rehabilitated to restore ecosystem functions, but may provide valuable habitat for invasive bigheaded carps [bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix)]. Use (residency and passages) of Swan Lake by invasive bigheaded carps was monitored using acoustic telemetry (n = 50 individuals/species) to evaluate the use of a large, restored habitat from 2004 to 2005. Passages (entrances/exits) by bigheaded carps were highest in winter, and residency was highest in the summer. Bighead carp backwater use was associated with the differences in temperature between the main channel and backwater, and passages primarily occurred between 18:00 h and midnight. Silver carp backwater use was positively correlated with water level and main channel discharge, and fewer passages occurred between 12:00 h and 18:00 h than during any other time of day. Harvest occurring during summer or high main channel discharge could reduce backwater abundances while maintenance of low water levels could reduce overall backwater use. Conclusions from this study regarding the timing of bigheaded carps' use of backwater habitats are critical to integrated pest management plans to control invasive species.

  15. Plant pollinator interactions: comparison between an invasive and a native congeneric species

    Science.gov (United States)

    Vanparys, Valérie; Meerts, Pierre; Jacquemart, Anne-Laure

    2008-11-01

    Plant-pollinator interactions determine reproductive success for animal-pollinated species and, in the case of invasive plants, they are supposed to play an important role in invasive success. We compared the invasive Senecio inaequidens to its native congener S. jacobaea in terms of interactions with pollinators. Visitor guild, visitation rate, and seed set were compared over 3 years in three sites in Belgium. Floral display (capitula number and arrangement) and phenology were quantified, and visiting insects were individually censused, i.e. number of visited capitula and time per visited capitulum. As expected from capitula resemblance, visitor guilds of both species were very similar (proportional similarity = 0.94). Senecio inaequidens was visited by 33 species, versus 36 for S. jacobaea. For both species, main visitors were Diptera, especially Syrphidae, and Hymenoptera. Visitation rate averaged 0.13 visitor per capitulum per 10 min for S. inaequidens against 0.08 for S. jacobaea. However, insects visited more capitula per plant on S. jacobaea, due to high capitula density (886 m -2 versus 206 m -2 for S. inaequidens), which is likely to increase self-pollen deposition considerably. Seed set of S. jacobaea was lower than that of S. inaequidens. We suggest that floral display is the major factor explaining the differences in insect visitation and seed set between the two Senecio species.

  16. Optimal control applied to native-invasive species competition via a PDE model

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    Wandi Ding

    2012-12-01

    Full Text Available We consider an optimal control problem of a system of parabolic partial differential equations modelling the competition between an invasive and a native species. The motivating example is cottonwood-salt cedar competition, where the effect of disturbance in the system (such as flooding is taken to be a control variable. Flooding being detrimental at low and high levels, and advantageous at medium levels led us to consider the quadratic growth function of the control. The objective is to maximize the native species and minimize the invasive species while minimizing the cost of implementing the control. An existence result for an optimal control is given. Numerical examples are presented to illustrate the results.

  17. Effects of urbanization on the distribution and abundance of amphibians and invasive species in southern California streams

    Science.gov (United States)

    Riley, S.P.D.; Busteed, G.T.; Kats, L.B.; Vandergon, T.L.; Lee, L.F.S.; Dagit, R.G.; Kerby, J.L.; Fisher, R.N.; Sauvajot, R.M.

    2005-01-01

    Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and exotic predators and characterized stream habitat and invertebratecommunities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish (Procambarus clarkii) and fish, and had fewer native species such as California newts (Taricha torosa) and California treefrogs (Hyla cadaverina). These effects seemed particularly evident above 8% development, a result coincident with other urban stream studies that show negative impacts beginning at 10-15% urbanization. For Pacific treefrogs (H. regilla), the most widespread native amphibian, abundance was lower in the presence of exotic crayfish, although direct urbanization effects were not found. Benthic macroinvertebrate communities were also less diverse in urban streams, especially for sensitive species. Faunal community changes in urban streams may be related to changes in physical stream habitat, such as fewer pool and more run habitats and increased water depth and flow, leading to more permanent streams. Variation in stream permanence was particularly evident in 2002, a dry year when many natural streams were dry but urban streams were relatively unchanged. Urbanization has significantly altered stream habitat in this region and may enhance invasion by exotic species and negatively affect diversity and abundance of native amphibians. ??2005 Society for Conservation Biology.

  18. Does temperature-mediated reproductive success drive the direction of species displacement in two invasive species of leafminer fly?

    Directory of Open Access Journals (Sweden)

    Haihong Wang

    Full Text Available Liriomyza sativae and L. trifolii (Diptera: Agromyzidae are two highly invasive species of leafmining flies, which have become established as pests of horticultural crops throughout the world. In certain regions where both species have been introduced, L. sativae has displaced L. trifolii, whereas the opposite has occurred in other regions. These opposing outcomes suggest that neither species is an inherently superior competitor. The regions where these displacements have been observed (southern China, Japan and western USA are climatically different. We determined whether temperature differentially affects the reproductive success of these species and therefore if climatic differences could affect the outcome of interspecific interactions where these species are sympatric. The results of life table parameters indicate that both species can develop successfully at all tested temperatures (20, 25, 31, 33°C. L. sativae had consistently higher fecundities at all temperatures, but L. trifolii developed to reproductive age faster. Age-stage specific survival rates were higher for L. sativae at low temperatures, but these were higher for L. trifolii at higher temperatures. We then compared the net reproductive rates (R0 for both species in pure and mixed cultures maintained at the same four constant temperatures. Both species had significantly lower net reproductive rates in mixed species cultures compared with their respective pure species cultures, indicating that both species are subject to intense interspecific competition. Net reproductive rates were significantly greater for L. sativae than for L. trifolii in mixed species groups at the lower temperatures, whereas the opposite occurred at the higher temperature. Therefore, interactions between the species are temperature dependent and small differences could shift the competitive balance between the species. These temperature mediated effects may contribute to the current ongoing displacement

  19. Hyperspectral remote sensing tools for quantifying plant litter and invasive species in arid ecosystems

    Science.gov (United States)

    Nagler, Pamela L.; Sridhar, B.B. Maruthi; Olsson, Aaryn Dyami; Glenn, Edward P.; van Leeuwen, Willem J.D.; Thenkabail, Prasad S.; Huete, Alfredo; Lyon, John G.

    2012-01-01

    Green vegetation can be distinguished using visible and infrared multi-band and hyperspectral remote sensing methods. The problem has been in identifying and distinguishing the non-photosynthetically active radiation (PAR) landscape components, such as litter and soils, and from green vegetation. Additionally, distinguishing different species of green vegetation is challenging using the relatively few bands available on most satellite sensors. This chapter focuses on hyperspectral remote sensing characteristics that aim to distinguish between green vegetation, soil, and litter (or senescent vegetation). Quantifying litter by remote sensing methods is important in constructing carbon budgets of natural and agricultural ecosystems. Distinguishing between plant types is important in tracking the spread of invasive species. Green leaves of different species usually have similar spectra, making it difficult to distinguish between species. However, in this chapter we show that phenological differences between species can be used to detect some invasive species by their distinct patterns of greening and dormancy over an annual cycle based on hyperspectral data. Both applications require methods to quantify the non-green cellulosic fractions of plant tissues by remote sensing even in the presence of soil and green plant cover. We explore these methods and offer three case studies. The first concerns distinguishing surface litter from soil using the Cellulose Absorption Index (CAI), as applied to no-till farming practices where plant litter is left on the soil after harvest. The second involves using different band combinations to distinguish invasive saltcedar from agricultural and native riparian plants on the Lower Colorado River. The third illustrates the use of the CAI and NDVI in time-series analyses to distinguish between invasive buffelgrass and native plants in a desert environment in Arizona. Together the results show how hyperspectral imagery can be applied to

  20. From Points to Forecasts: Predicting Invasive Species Habitat Suitability in the Near Term

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    Tracy R. Holcombe

    2010-05-01

    Full Text Available We used near-term climate scenarios for the continental United States, to model 12 invasive plants species. We created three potential habitat suitability models for each species using maximum entropy modeling: (1 current; (2 2020; and (3 2035. Area under the curve values for the models ranged from 0.92 to 0.70, with 10 of the 12 being above 0.83 suggesting strong and predictable species-environment matching. Change in area between the current potential habitat and 2035 ranged from a potential habitat loss of about 217,000 km2, to a potential habitat gain of about 133,000 km2.

  1. Analysis of a native whitefly transcriptome and its sequence divergence with two invasive whitefly species

    Directory of Open Access Journals (Sweden)

    Wang Xiao-Wei

    2012-10-01

    Full Text Available Abstract Background Genomic divergence between invasive and native species may provide insight into the molecular basis underlying specific characteristics that drive the invasion and displacement of closely related species. In this study, we sequenced the transcriptome of an indigenous species, Asia II 3, of the Bemisia tabaci complex and compared its genetic divergence with the transcriptomes of two invasive whiteflies species, Middle East Asia Minor 1 (MEAM1 and Mediterranean (MED, respectively. Results More than 16 million reads of 74 base pairs in length were obtained for the Asia II 3 species using the Illumina sequencing platform. These reads were assembled into 52,535 distinct sequences (mean size: 466 bp and 16,596 sequences were annotated with an E-value above 10-5. Protein family comparisons revealed obvious diversification among the transcriptomes of these species suggesting species-specific adaptations during whitefly evolution. On the contrary, substantial conservation of the whitefly transcriptomes was also evident, despite their differences. The overall divergence of coding sequences between the orthologous gene pairs of Asia II 3 and MEAM1 is 1.73%, which is comparable to the average divergence of Asia II 3 and MED transcriptomes (1.84% and much higher than that of MEAM1 and MED (0.83%. This is consistent with the previous phylogenetic analyses and crossing experiments suggesting these are distinct species. We also identified hundreds of highly diverged genes and compiled sequence identify data into gene functional groups and found the most divergent gene classes are Cytochrome P450, Glutathione metabolism and Oxidative phosphorylation. These results strongly suggest that the divergence of genes related to metabolism might be the driving force of the MEAM1 and Asia II 3 differentiation. We also analyzed single nucleotide polymorphisms within the orthologous gene pairs of indigenous and invasive whiteflies which are helpful for

  2. Effects of invasive plant species on pollinator service and reproduction in native plants at Acadia National Park

    Science.gov (United States)

    Stubbs, C.J.; Drummond, F.; Ginsberg, H.

    2007-01-01

    Invasive plant species can have profound negative effects on natural communities by competively excluding native species. Berberis thunbergii (Japanese barberry), Frangula alnus (glossy or alder buckthorn) and Lythrum salicaria (purple loosestrife) are invasive species known to reduce native plant diversity and are thus of great concern to Acadia National Park. Pollinators visit them for nectar and pollen. The effects of invasive plant species on pollinator behavior were investigated by comparing pollinator visitation to co-flowering native and invasive species with visitation to native species growing alone. The effect of invasives on pollination of native plants was studied by comparing fruit set in patches of the native species growing near invasives with patches far from invasive species in Acadia National Park. The coflowering pairs were as follows: in the spring native Vaccinium angustifolium (lowbush blueberry) was paired with B. thunbergii; in early summer native Viburnum nudum (wild raisin) was paired with F. alnus ; in late summer native Spiraea alba (meadowsweet) was paired with L. salicaria. We investigated whether these invasives competed with native plants for pollinators in Acadia and thus negatively affected native plant reproduction. Our objectives were to determine: 1) the influence, if any, of each invasive on pollinator visitation to a co-flowering native species, 2) factors that might affect visitation, 3) invasive pollen transfer to native plants, and 4) whether invasives influence native plant reproduction (fruit set). Our findings indicate that at times the number of flower visitors to natives was lower or the species composition of visitors different when invasives were present, that invasives sometimes attracted more pollinators, that generally the invasives were more rewarding as far as nectar and pollen availability for pollinators, and that generally native plant fruit set and seed set was not significantly lowered in the presence of

  3. INVASIVE PLANTS IN MOUNTAINOUS REMNANT FOREST: RECOMMENDATION FOR CHOOSING BEST DECISION FOR INVASIVE SPECIES MANAGEMENT OF Cestrum aurantiacum Lindl.

    Directory of Open Access Journals (Sweden)

    Decky Indrawan Junaedi

    2012-01-01

    Full Text Available Cestrum aurantiacum Lindl. is an exotic species found in native remnant forest of GPNP which is located inside the Cibodas Botanic Garden (CBG. Risk assessment is an important tool to choose best decision for invasive plant management.  Risk assessment analysis on C. aurantiacum in Cibodas Botanic Garden was conducted using Multi Criteria Decision Analysis (MCDA method.  Analytical Hierarchy Process (AHP used in the valuation process. Three sub-criteria used: minimizing the ecological impact, minimizing the management cost, and maximizing the public acceptance. Five management alternatives were used: do nothing (DN, eradication (E, containment (C, bio-control (BC and harvesting (H. Harvesting (H recommended as the best management decision for C. aurantiacumin at CBG remnant forest. This harvesting decision is not only creating environment/ ecosystem remediation but also as sources of fund in the management activity of the area.

  4. Invasive species and habitat degradation in Iberian streams: an analysis of their role in freshwater fish diversity loss.

    Science.gov (United States)

    Hermoso, Virgilio; Clavero, Miguel; Blanco-Garrido, Francisco; Prenda, José

    2011-01-01

    Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives' decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions.

  5. Early detection of potentially invasive invertebrate species in Mytilus galloprovincialis Lamarck, 1819 dominated communities in harbours

    Science.gov (United States)

    Preda, Cristina; Memedemin, Daniyar; Skolka, Marius; Cogălniceanu, Dan

    2012-12-01

    Constanţa harbour is a major port on the western coast of the semi-enclosed Black Sea. Its brackish waters and low species richness make it vulnerable to invasions. The intensive maritime traffic through Constanţa harbour facilitates the arrival of alien species. We investigated the species composition of the mussel beds on vertical artificial concrete substrate inside the harbour. We selected this habitat for study because it is frequently affected by fluctuating levels of temperature, salinity and dissolved oxygen, and by accidental pollution episodes. The shallow communities inhabiting it are thus unstable and often restructured, prone to accept alien species. Monthly samples were collected from three locations from the upper layer of hard artificial substrata (maximum depth 2 m) during two consecutive years. Ten alien macro-invertebrate species were inventoried, representing 13.5% of the total number of species. Two of these alien species were sampled starting the end of summer 2010, following a period of high temperatures that triggered hypoxia, causing mass mortalities of benthic organisms. Based on the species accumulation curve, we estimated that we have detected all benthic alien species on artificial substrate from Constanţa harbour, but additional effort is required to detect all the native species. Our results suggest that monitoring of benthic communities at small depths in harbours is a simple and useful tool in early detection of potentially invasive alien species. The selected habitat is easily accessible, the method is low-cost, and the samples represent reliable indicators of alien species establishment.

  6. Determination of antimicrobial and heavy metal resistance profiles of some bacteria isolated from aquatic amphibian and reptile species.

    Science.gov (United States)

    Hacioglu, Nurcihan; Tosunoglu, Murat

    2014-01-01

    The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from aquatic animals (Lissotriton vulgaris, Pelophylax ridibundus, Emys orbicularis, Mauremys rivulata, and Natrix natrix) in Turkey (Kavak Delta). A total of 153 bacteria have been successfully isolated from cloaca and oral samples of the aquatic amphibians and reptilians which were found, namely, Aeromonas sp. (n = 29), Plesiomonas sp. (n = 7), Vibrio sp. (n = 12), Citrobacter sp. (n = 12), Enterobacter sp. (n = 11), Escherichia sp. (n = 22), Klebsiella sp. (n = 22), Edwardsiella sp. (n = 6), Hafnia sp. (n = 1), Proteus sp. (n = 19), Providencia sp. (n = 8), and Pseudomonas sp. (n = 4). In terms of antibiotic and heavy metal susceptibility testing, each isolate was tested against 12 antibiotics and 4 metals. There was a high incidence of resistance to cefoxitin (46.40 %), ampicillin (44.44 %), erythromycin (35.29 %), and a low incidence of resistance to gentamicin (6.53 %), kanamycin (8.49 %), chloramphenicol (9.15 %), and cefotaxime (10.45 %). The multiple antibiotic resistance index of each bacterial species indicated that bacteria from raised amphibians and reptiles have been exposed to tested antibiotics, with results ranging from 0 to 0.58. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from100 to >3,200 μg/mL. According to these results, a significant occurrence of bacteria in the internal organs of reptiles and amphibians, with a high incidence of resistance against antibiotics and heavy metals, may risk aquatic animals and the public health. These data appoint the importance of epidemiological surveillance and microbiological monitoring and reinforce the need to implement environment protection programs for amphibian and reptile species.

  7. Low frequency vibrations induce malformations in two aquatic species in a frequency-, waveform-, and direction-specific manner.

    Directory of Open Access Journals (Sweden)

    Laura N Vandenberg

    Full Text Available Environmental toxicants such as industrial wastes, air particulates from machinery and transportation vehicles, and pesticide run-offs, as well as many chemicals, have been widely studied for their effects on human and wildlife populations. Yet other potentially harmful environmental pollutants such as electromagnetic pulses, noise and vibrations have remained incompletely understood. Because developing embryos undergo complex morphological changes that can be affected detrimentally by alterations in physical forces, they may be particularly susceptible to exposure to these types of pollutants. We investigated the effects of low frequency vibrations on early embryonic development of two aquatic species, Xenopus laevis (frogs and Danio rerio (zebrafish, specifically focusing on the effects of varying frequencies, waveforms, and applied direction. We observed treatment-specific effects on the incidence of neural tube defects, left-right patterning defects and abnormal tail morphogenesis in Xenopus tadpoles. Additionally, we found that low frequency vibrations altered left-right patterning and tail morphogenesis, but did not induce neural tube defects, in zebrafish. The results of this study support the conclusion that low frequency vibrations are toxic to aquatic vertebrates, with detrimental effects observed in two important model species with very different embryonic architectures.

  8. Evaluation of biomass of some invasive weed species as substrate for oyster mushroom (Pleurotus spp.) cultivation.

    Science.gov (United States)

    Mintesnot, Birara; Ayalew, Amare; Kebede, Ameha

    2014-01-15

    This study assessed the bioconversion of Agriculture wastes like invasive weeds species (Lantana camara, Prosopis juliflora, Parthenium hysterophorus) as a substrate for oyster mushroom (Pleurotus species) cultivation together with wheat straw as a control. The experiment was laid out in factorial combination of substrates and three edible oyster mushroom species in a Completely Randomized Design (CRD) with three replications. Pleurotus ostreatus gave significantly (p production rate of 3.13 was recorded for P. ostreatus grown on P. hysterophorus. The highest total ash content (13.90%) was recorded for P. florida grown on L. camara. while the lowest (6.92%) was for P. sajor-caju grown on the P. juliflora. Crude protein ranged from 40.51-41.48% for P. florida grown on P. hysterophorus and L. camara. Lowest crude protein content (30.11%) was recorded for P. ostreatus grown on wheat straw. The crude fiber content (12.73%) of P. sajor-caju grown on wheat straw was the highest. The lowest crude fiber (5.19%) was recorded for P. ostreatus on P. juliflora. Total yield had a positive and significant correlation with biological efficiency and production. Utilization of the plant biomass for mushroom cultivation could contribute to alleviating ecological impact of invasive weed species while offering practical option to mitigating hunger and malnutrition in areas where the invasive weeds became dominant.

  9. Alkaloid concentration of the invasive plant species Ulex europaeus in relation to geographic origin and herbivory

    Science.gov (United States)

    Hornoy, Benjamin; Atlan, Anne; Tarayre, Michèle; Dugravot, Sébastien; Wink, Michael

    2012-11-01

    In the study of plant defense evolution, invasive plant species can be very insightful because they are often introduced without their enemies, and traits linked to defense can be released from selective pressures and evolve. Further, studying plant defense evolution in invasive species is important for biological control and use of these species. In this study, we investigated the evolution of the defensive chemicals quinolizidine alkaloids (QAs) in the invasive species gorse, Ulex europaeus. Using a common garden experiment, our goals were to characterize the role of QAs relative to specialist enemies of gorse and to investigate if QA concentration evolved in invaded regions, where gorse was introduced without these enemies. Our results showed that pod infestation rate by the seed predator Exapion ulicis and infestation by the rust pathogen Uromyces genistae-tinctoriae were negatively correlated to concentration of the QA lupanine. Quinolizidine alkaloid concentration was very variable between individuals, both within and among populations, but it was not different between native and invaded regions, suggesting that no evolution of decreased resistance occurred after gorse lost its enemies. Our study also suggests that QA concentrations are traits integrated into seed predation avoidance strategies of gorse, with plants that mass-fruit in spring but do not escape pod infestation in time being richer in QAs.

  10. Paving the way for invasive species: road type and the spread of common ragweed (Ambrosia artemisiifolia).

    Science.gov (United States)

    Joly, Martin; Bertrand, Pascale; Gbangou, Roland Y; White, Marie-Catherine; Dubé, Jean; Lavoie, Claude

    2011-09-01

    Roads function as prime habitats and corridors for invasive plant species. Yet despite the diversity of road types, there is little research on the influence of these types on the spread of invaders. Common ragweed (Ambrosia artemisiifolia), a plant producing large amounts of allergenic pollen, was selected as a species model for examining the impact of road type on the spread of invasive plants. We examined this relationship in an agricultural region of Quebec, Canada. We mapped plant distribution along different road types, and constructed a model of species presence. Common ragweed was found in almost all sampling sites located along regional (97%) and local paved (81%) roads. However, verges of unpaved local roads were rarely (13%) colonized by the plant. A model (53% of variance explained), constructed with only four variables (paved regional roads, paved local roads, recently mown road verges, forest cover), correctly predicted (success rate: 89%) the spatial distribution of common ragweed. Results support the hypothesis that attributes associated with paved roads strongly favour the spread of an opportunistic invasive plant species. Specifically, larger verges and greater disturbance associated with higher traffic volume create propitious conditions for common ragweed. To date, emphasis has been placed on controlling the plant in agricultural fields, even though roadsides are probably a much larger seed source. Strategies for controlling the weed along roads have only focused on major highways, even though the considerable populations along local roads also contribute to the production of pollen. Management prioritizations developed to control common ragweed are thus questionable.

  11. Acacia saligna: an invasive species on the coast of Molise (southern Italy

    Directory of Open Access Journals (Sweden)

    Calabrese V

    2017-02-01

    Full Text Available Italy is one of the European countries most affected by biological invasions. In this study, we focused on the impact of Acacia saligna, an Australian invasive plant species, on the coastal ecosystem’s ecology and biodiversity along the sandy coasts of Molise (southern Italy. We analyzed data from 61 vegetation plots recorded in coastal pine forest and Mediterranean scrub habitats of Molise throughout the preparatory actions of the “LIFE Maestrale” project (NAT/IT/000262. In order to study the ecological impact of Acacia saligna comparing invaded and non-invaded areas, we first assigned the Ellenberg’s indicator values to each plant species, which were then used to relate the presence of Acacia saligna with ecological characteristics of sites through a generalized linear model (GLM. Our results showed a significant positive relationship between the presence of Acacia saligna and high levels of soil nutrients and, on the contrary, a negative relationship with the presence of mesophilic species, which are typical of the community interest habitats of pine forest (2270*. The use of ecological indicators is effective to pinpoint the ecological effects of biological invasions, as well as to evaluate habitat conservation state and to identify vulnerable native species.

  12. Investigating Invasives

    Science.gov (United States)

    Lightbody, Mary

    2008-01-01

    Invasive species, commonly known as "invasives," are nonnative plants, animals, and microbes that completely take over and change an established ecosystem. The consequences of invasives' spread are significant. In fact, many of the species that appear on the Endangered Species list are threatened by invasives. Therefore, the topic of invasive…

  13. Using economic instruments to develop effective management of invasive species: insights from a bioeconomic model.

    Science.gov (United States)

    McDermott, Shana M; Irwin, Rebecca E; Taylor, Brad W

    2013-07-01

    Economic growth is recognized as an important factor associated with species invasions. Consequently, there is increasing need to develop solutions that combine economics and ecology to inform invasive species management. We developed a model combining economic, ecological, and sociological factors to assess the degree to which economic policies can be used to control invasive plants. Because invasive plants often spread across numerous properties, we explored whether property owners should manage invaders cooperatively as a group by incorporating the negative effects of invader spread in management decisions (collective management) or independently, whereby the negative effects of invasive plant spread are ignored (independent management). Our modeling approach used a dynamic optimization framework, and we applied the model to invader spread using Linaria vulgaris. Model simulations allowed us to determine the optimal management strategy based on net benefits for a range of invader densities. We found that optimal management strategies varied as a function of initial plant densities. At low densities, net benefits were high for both collective and independent management to eradicate the invader, suggesting the importance of early detection and eradication. At moderate densities, collective management led to faster and more frequent invader eradication compared to independent management. When we used a financial penalty to ensure that independent properties were managed collectively, we found that the penalty would be most feasible when levied on a property's perimeter boundary to control spread among properties. At the highest densities, the optimal management strategy was "do nothing" because the economic costs of removal were too high relative to the benefits of removal. Spatial variation in L. vulgaris densities resulted in different optimal management strategies for neighboring properties, making a formal economic policy to encourage invasive species removal

  14. Competition for shelter between four invasive gobiids and two native benthic fish species

    Institute of Scientific and Technical Information of China (English)

    N. VAN KESSEL; M. DORENBOSCH; M.R.M. DE BOER; R.S.E.W. LEUVEN; G. VAN DER VELDE

    2011-01-01

    Recent invasions by non-native gobiid fish species that are ongoing in the Western European rivers Rhine and Meuse,will lead to interactions with native benthic fish species.Since both non-native gobiids and native benthic species are bottom dwelling species with a preference for shelter during at least part of their life cycle,it is likely that competition for shelter will occur between these non-native and native species when shelter is a limiting factor.To investigate the importance of this mechanism for species replacements,various habitat choice experiments were conducted between two common native benthic fish species ( Cottus perifretum and Barbatula barbatula) and four invasive non-native gobiid species ( Proterorhinus semilunaris,Neogobius melanostomus,N.kessleri and N.fluviatilis).The first series of single specimen experiments determined the habitat choice of each individual fish species.In a second series of competition experiments,shifts in habitat choice in comparison with the previously observed habitat choice,were determined when a native benthic fish species co-occurred with non-native gobiid species.Native C.perifretum displayed a significant shift in habitat choice in co-occurrence with the gobiids N.kessleri or P.semilunaris.C.perifretum was outcompeted and moved from the available shelter place to less preferred habitat types.During the competition experiments no change in habitat choice of B.barbatula was shown.Our study therefore suggests that competition for shelter is likely to occur in rivers invaded by N.kessleri and P.semilunaris at sites where shelter is limiting [Current Zoology 57 (6):844-851,2011].

  15. Competition for shelter between four invasive gobiids and two native benthic fish species

    Directory of Open Access Journals (Sweden)

    N. VAN KESSEL, M. DORENBOSCH, M.R.M. DE BOER, R.S.E.W. LEUVEN,G. VAN DER VELDE

    2011-12-01

    Full Text Available Recent invasions by non-native gobiid fish species that are ongoing in the Western European rivers Rhine and Meuse, will lead to interactions with native benthic fish species. Since both non-native gobiids and native benthic species are bottom dwelling species with a preference for shelter during at least part of their life cycle, it is likely that competition for shelter will occur between these non-native and native species when shelter is a limiting factor. To investigate the importance of this mechanism for species replacements, various habitat choice experiments were conducted between two common native benthic fish species (Cottus perifretum and Barbatula barbatula and four invasive non-native gobiid species (Proterorhinus semilunaris, Neogobius melanostomus, N. kessleri and N. fluviatilis. The first series of single specimen experiments determined the habitat choice of each individual fish species. In a second series of competition experiments, shifts in habitat choice in comparison with the previously observed habitat choice, were determined when a native benthic fish species co-occurred with non-native gobiid species. Native C. perifretum displayed a significant shift in habitat choice in co-occurrence with the gobiids N. kessleri or P. semilunaris. C. perifretum was outcompeted and moved from the available shelter place to less preferred habitat types. During the competition experiments no change in habitat choice of B. barbatula was shown. Our study therefore suggests that competition for shelter is likely to occur in rivers invaded by N. kessleri and P. semilunaris at sites where shelter is limiting [Current Zoology 57 (6: 844–851, 2011].

  16. Nutritional composition of aquatic species in Laotian rice field ecosystems : possible impact of reduced biodiversity

    OpenAIRE

    Nurhasan, Mulia

    2008-01-01

    The population density of Laos PDR has increased from 15 persons per square km in 1985 to 19 persons in 1995 and to 24 persons in 2005. This has threatened food security, which in Laos PDR is generally synonymous with rice availability. Rice production in Laos rose by 70 percent from 1990 to 2004. Evidence from Vietnam, Malaysia and Central Thailand has shown that the rise of rice production steadily decreases the population of aquatic animals in rice field ecosystems, as a result of higher a...

  17. A framework for sustainable invasive species management: environmental, social and economic objectives

    Science.gov (United States)

    Larson, Diane L.; Phillips-Mao, Laura; Quiram, Gina; Sharpe, Leah; Stark, Rebecca; Sugita, Shinya; Weiler, Annie

    2011-01-01

    Applying the concept of sustainability to invasive species management (ISM) is challenging but necessary, given the increasing rates of invasion and the high costs of invasion impacts and control. To be sustainable, ISM must address environmental, social, and economic factors (or *pillars*) that influence the causes, impacts, and control of invasive species across multiple spatial and temporal scales. Although these pillars are generally acknowledged, their implementation is often limited by insufficient control options and significant economic and political constraints. In this paper, we outline specific objectives in each of these three *pillars* that, if incorporated into a management plan, will improve the plan's likelihood of sustainability. We then examine three case studies that illustrate how these objectives can be effectively implemented. Each pillar reinforces the others, such that the inclusion of even a few of the outlined objectives will lead to more effective management that achieves ecological goals, while generating social support and long-term funding to maintain projects to completion. We encourage agency directors and policy-makers to consider sustainability principles when developing funding schemes, management agendas, and policy.

  18. Invasive species and biodiversity crises: testing the link in the late devonian.

    Directory of Open Access Journals (Sweden)

    Alycia L Stigall

    Full Text Available During the Late Devonian Biodiversity Crisis, the primary driver of biodiversity decline was the dramatic reduction in speciation rates, not elevated extinction rates; however, the causes of speciation decline have been previously unstudied. Speciation, the formation of new species from ancestral populations, occurs by two primary allopatric mechanisms: vicariance, where the ancestral population is passively divided into two large subpopulations that later diverge and form two daughter species, and dispersal, in which a small subset of the ancestral population actively migrates then diverges to form a new species. Studies of modern and fossil clades typically document speciation by vicariance in much higher frequencies than speciation by dispersal. To assess the mechanism behind Late Devonian speciation reduction, speciation rates were calculated within stratigraphically constrained species-level phylogenetic hypotheses for three representative clades and mode of speciation at cladogenetic events was assessed across four clades in three phyla: Arthropoda, Brachiopoda, and Mollusca. In all cases, Devonian taxa exhibited a congruent reduction in speciation rate between the Middle Devonian pre-crisis interval and the Late Devonian crisis interval. Furthermore, speciation via vicariance is almost entirely absent during the crisis interval; most episodes of speciation during this time were due to dispersal. The shutdown of speciation by vicariance during this interval was related to widespread interbasinal species invasions. The lack of Late Devonian vicariance is diametrically opposed to the pattern observed in other geologic intervals, which suggests the loss of vicariant speciation attributable to species invasions during the Late Devonian was a causal factor in the biodiversity crisis. Similarly, modern ecosystems, in which invasive species are rampant, may be expected to exhibit similar shutdown of speciation by vicariance as an outcome of the

  19. How complete is our knowledge of the ecosystem services impacts of Europe's top 10 invasive species?

    Science.gov (United States)

    McLaughlan, C.; Gallardo, B.; Aldridge, D. C.

    2014-01-01

    Invasive non-native species have complex multilevel impacts on their introduced ecosystems, leading to far-ranging effects on fundamental ecosystem services, from the provision of food from that system, to human health and wellbeing. For this reason, there is an emerging interest in basing risk assessments not only on the species' ecological and economic impacts, but also on the effects related to ecosystem services. We investigated the quality and extent of baseline data detailing the effects that the top 10 of the 'worst' invasive species in Europe are having on their adopted ecosystems. The results were striking, as the 10 species showed a wide range of impacts on ecosystem services, a number of which were actually positive for ecosystems and human well-being. For instance, the bivalve Dreissena polymorpha is a prolific biofouler of pipes and boats, but it can improve water quality through its filtration of nuisance algae, a valuable effect that is often overlooked. We found that negative effects, particularly economic ones, were often assumed rather than quantitatively evidenced; for example, the cost of crop damage by species such as Myocastor coypus and Branta canadensis. In general, the evidence for impacts of these 'worst' invaders was severely lacking. We conclude that invasive species management requires prioritization, which should be based on informed and quantified assessment of the potential ecological and economic costs of species (both positive and negative), considered in the proper context of the invader and ecosystem. The Millennium Ecosystem Approach provides a useful framework to undertake such prioritization from a new perspective combining ecological and societal aspects. However, standard guidelines of evaluation are urgently needed in order to unify definitions, methods and evaluation scores.

  20. Relevance of risk predictions derived from a chronic species sensitivity distribution with cadmium to aquatic populations and ecosystems

    Science.gov (United States)

    Mebane, C.A.

    2010-01-01

    Criteria to protect aquatic life are intended to protect diverse ecosystems, but in practice are usually developed from compilations of single-species toxicity tests using standard test organisms that were tested in laboratory environments. Species sensitivity distributions (SSDs) developed from these compilations are extrapolated to set aquatic ecosystem criteria. The protectiveness of the approach was critically reviewed with a chronic SSD for cadmium comprising 27 species within 21 genera. Within the data set, one genus had lower cadmium effects concentrations than the SSD fifth percentile-based criterion, so in theory this genus, the amphipod Hyalella, could be lost or at least allowed some level of harm by this criteria approach. However, population matrix modeling projected only slightly increased extinction risks for a temperate Hyalella population under scenarios similar to the SSD fifth percentile criterion. The criterion value was further compared to cadmium effects concentrations in ecosystem experiments and field studies. Generally, few adverse effects were inferred from ecosystem experiments at concentrations less than the SSD fifth percentile criterion. Exceptions were behavioral impairments in simplified food web studies. No adverse effects were apparent in field studies under conditions that seldom exceeded the criterion. At concentrations greater than the SSD fifth percentile, the magnitudes of adverse effects in the field studies were roughly proportional to the laboratory-based fraction of species with adverse effects in the SSD. Overall, the modeling and field validation comparisons of the chronic criterion values generally supported the relevance and protectiveness of the SSD fifth percentile approach with cadmium. ?? 2009 Society for Risk Analysis.

  1. Species groups occupying different trophic levels respond differently to the invasion of semi-natural vegetation by Solidago canadensis

    NARCIS (Netherlands)

    Groot, de M.; Kleijn, D.; Jogan, N.

    2007-01-01

    We studied the impact of the invasive plant species Solidago canadensis on the species richness of vascular plants and the abundance, species richness and diversity of butterflies, hoverflies and carabid beetles in herbaceous semi-natural habitats near Ljubljana, Slovenia. The species groups were sa

  2. Forest legacies, climate change, altered disturbance regimes, invasive species and water

    Science.gov (United States)

    Stohlgren, T.; Jarnevich, C.; Kumar, S.

    2007-01-01

    The factors that must be considered in seeking to predict changes in water availability has been examined. These factors are the following: forest legacies including logging, mining, agriculture, grazing, elimination of large carnivores, human-caused wildfire, and pollution; climate change and stream flow; altered disturbances such as frequency intensity and pattern of wildfires and insect outbreaks as well as flood control; lastly, invasive species like forest pests and pathogens. An integrated approach quantifying the current and past condition trends can be combined with spatial and temporal modeling to develop future change in forest structures and water supply. The key is a combination of geographic information system technologies with climate and land use scenarios, while preventing and minimizing the effects of harmful invasive species.

  3. Biology and impacts of Pacific island invasive species 9. Capra hircus, the feral goat, (Mammalia: Bovidae)

    Science.gov (United States)

    Chynoweth, Mark W.; Litton, Creighton M.; Lepczyk, Christopher A.; Hess, Steve A.; Cordell, Susan

    2013-01-01

    Domestic goats, Capra hircus, were intentionally introduced to numerous oceanic islands beginning in the sixteenth century. The remarkable ability of C. hircus to survive in a variety of conditions has enabled this animal to become feral and impact native ecosystems on islands throughout the world. Direct ecological impacts include consumption and trampling of native plants, leading to plant community modification and transformation of ecosystem structure. While the negative impacts of feral goats are well-known and effective management strategies have been developed to control this invasive species, large populations persist on many islands. This review summarizes the impacts of feral goats on Pacific island ecosystems, and the management strategies available to control this invasive species.

  4. Alien invasive species and biological pollution of the Great Lakes Basin ecosystem[Great Lakes Water Quality Board : Report to the International Joint Commission

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-05-01

    The displacement of important native species in the Great Lakes is a result of an invasion by a succession of non indigenous aquatic species. These invasion also resulted in interference with the proper human water uses and cost billions of dollars. The problem was considered serious enough that the International Joint Commission asked the Great Lakes Water Quality Board in 1999 to review the regulations in place and make recommendations, if necessary, for the implementation of additional measures that could be considered to keep control over the introduction of alien invasive species. Escapes from aquaria, aquaculture, research and educational facilities, canal and diversion water flows, and release of live bait are all sources of this invasion. The effectiveness of alternative technologies to control the invasion was to be examined by the Board. Other efforts taking place to address the situation in the basin are being complemented by the publication of this report. It is considered that the most important source of alien invasive species (AIS) to the Great Lakes is the discharge of ballast water from shipping vessels coming from outside the United States and Canada. A major concern is the role played by vessels reporting no ballast on board (NOBOB) upon entering the basin. A number of recommendations were made concerning: (1) implementation and enforcement of the ballast water discharge standards agreed upon by both countries, (2) the evaluation of the effectiveness of alternative technologies to achieve ballast water discharge standards over the long term, combined with the use of chemical treatment while the evaluation is being performed, (3) the implementation of optimal management practices to control sediments in shipping vessels, (4) modifications to the design of shipping vessels, and (5) the monitoring and contingency plans in the event of a repeat scenario in the future. Composed of an equal number representatives from the United States and Canada, at

  5. Nutritional and antinutritional composition of the five species of aquatic edible insects consumed in Manipur, India.

    Science.gov (United States)

    Shantibala, T; Lokeshwari, R K; Debaraj, H

    2014-01-26

    The people living in Manipur have a distinct identity, culture, and food habits. They have a prototype culture of eating insects. In our study, the nutritive contents of five potentially-edible aquatic insects, Lethocerus indicus (Lepeletier and Serville) (Hemiptera: Belostomatidae), Laccotrephes maculatus (F.) (Nepidae), Hydrophilus olivaceous (F.) (Coleoptera: Dytiscidae), Cybister tripunctatus (Olivier), and Crocothemis servilia (Drury) (Odonata: Libellulidae), were analyzed to inform consumers about the nutritional quality of the insects and the suggested quantity of their intake. A good amount of protein content and high gross energy was recorded among the insects. The results showed high levels of sodium, calcium, and magnesium present in the insects, indicating that they are a good source of minerals. Antinutritional properties of these insects were below 0.52%, which is a non-toxic level. Aquatic insects, such as C. tripunctatus, also possesses strong antioxidant activity (110 µg/mL). Therefore, these insects can play a major role in food security, health, and environment management. It is essential to cultivate edible insects to maintain their population sustainability.

  6. Seasonal trends in growth and biomass accumulation of selected nutrients and metals in six species of emergent aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Behrends, L.L.; Bailey, E.; Bulls, M.J.; Coonrod, H.S.; Sikora, F.J.

    1996-05-01

    Growth and biomass accumulation of selected nutrients and trace metals were monitored for six species of aquatic macrophytes during June, August and November, 1993. Plant species were cultivated in two polyculture treatments, each replicated three times. Polyculture I consisted of Scirpus acutus (hardstem bullrush), Phragmites communes (common reed), and Phalaris arundinacea (canary grass). Polyculture H consisted of Typha spp. (cattail), Scirpus atrovirens (green bullrush), and Scirpus cyperinus (wool grass). Each of the six cells (6 x 9 x 0.6 m), was operated as a gravel-substrate, subsurface-flow wetlands in a continuous recirculating mode. At six week intervals, macro, micro and trace elements were dissolved and added to the sump of the recirculating system. On each of three sampling dates, replicate shoot and root samples were collected, segregated by species and tissue type (roots, rhizomes, stems and leaves), and prepared for gravimetric biomass estimates and chemical analysis. Tissue specific concentrations of N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, were determined on each date for each species and tissue type. Results will be discussed with respect to species specific growth rates, biomass accumulation, and seasonal uptake and translocation of plant nutrients.

  7. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes

    Science.gov (United States)

    Kowalski, Kurt P.; Bacon, Charles R.; Bickford, Wesley A.; Braun, Heather A.; Clay, Keith; Leduc-Lapierre, Michele; Lillard, Elizabeth; McCormick, Melissa K.; Nelson, Eric; Torres, Monica; White, James W. C.; Wilcox, Douglas A.

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis andPhragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

  8. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes.

    Science.gov (United States)

    Kowalski, Kurt P; Bacon, Charles; Bickford, Wesley; Braun, Heather; Clay, Keith; Leduc-Lapierre, Michèle; Lillard, Elizabeth; McCormick, Melissa K; Nelson, Eric; Torres, Monica; White, James; Wilcox, Douglas A

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

  9. Considering native and exotic terrestrial reptiles in island invasive species eradication programmes in the Tropical Pacific

    Science.gov (United States)

    Fisher, Richard N.; Veitch, C.R.; Clout, Mike N.; Towns, D. R.

    2010-01-01

    Most island restoration projects with reptiles, either as direct beneficiaries of conservation or as indicators of recovery responses, have been on temperate or xeric islands. There have been decades of research, particularly on temperate islands in New Zealand, on the responses of native reptiles to mammal eradications but very few studies in tropical insular systems. Recent increases in restoration projects involving feral mammal eradications in the tropical Pacific have led to several specific challenges related to native and invasive reptiles. This paper reviews these challenges and discusses some potential solutions to them. The first challenge is that the tropical Pacific herpetofauna is still being discovered, described and understood. There is thus incomplete knowledge of how eradication activities may affect these faunas and the potential risks facing critical populations of these species from these eradication actions. The long term benefit of the removal of invasives is beneficial, but the possible short term impacts to small populations on small islands might be significant. The second challenge is that protocols for monitoring the responses of these species are not well documented but are often different from those used in temperate or xeric habitats. Lizard monitoring techniques used in the tropical Pacific are discussed. The third challenge involves invasive reptiles already in the tropical Pacific, some of which could easily spread accidentally through eradication and monitoring operations. The species posing the greatest threats in this respect are reviewed, and recommendations for biosecurity concerning these taxa are made.

  10. Biological control of invasive plant species: a reassessment for the Anthropocene.

    Science.gov (United States)

    Seastedt, Timothy R

    2015-01-01

    The science of finding, testing and releasing herbivores and pathogens to control invasive plant species has achieved a level of maturity and success that argues for continued and expanded use of this program. The practice, however, remains unpopular with some conservationists, invasion biologists, and stakeholders. The ecological and economic benefits of controlling densities of problematic plant species using biological control agents can be quantified, but the risks and net benefits of biological control programs are often derived from social or cultural rather than scientific criteria. Management of invasive plants is a 'wicked problem', and local outcomes to wicked problems have both positive and negative consequences differentially affecting various groups of stakeholders. The program has inherent uncertainties; inserting species into communities that are experiencing directional or even transformational changes can produce multiple outcomes due to context-specific factors that are further confounded by environmental change drivers. Despite these uncertainties, biological control could play a larger role in mitigation and adaptation strategies used to maintain biological diversity as well as contribute to human well-being by protecting food and fiber resources.

  11. Macroalgal assemblages of disturbed coastal detritic bottoms subject to invasive species

    Science.gov (United States)

    Klein, Judith C.; Verlaque, Marc

    2009-04-01

    Characteristic flora and fauna that are highly sensitive to disturbances colonize coastal detritic bottoms in the Mediterranean Sea. In the present study, a comparison of the assemblage composition and colonization by invasive macroalgae was made between two coastal detritic macrophyte assemblages, one dominated by rhodoliths (free-living non-geniculate Corallinales) and the other dominated by fleshy algae, in an area that has been exposed to important levels of anthropogenic disturbance, mainly pollution (including changed sedimentation regimes) in the recent past (bay of Marseilles, France). In comparison with less strongly impacted Mediterranean regions, the macrophyte assemblages in the bay of Marseilles were characteristic in terms of species identity and richness of coastal detritic macrophyte assemblages. However, extremely low species abundance (cover) was observed. As far as invasive species were concerned, Caulerpa racemosa var. cylindracea was only abundant in the rhodolith assemblage whereas the two invasive Rhodophyta Asparagopsis armata and Womersleyella setacea were mainly found in the fleshy algae assemblage. The seasonality observed in the Rhodolith assemblage seemed to be related to the development of C. racemosa var. cylindracea and did not follow the typical pattern of other Mediterranean assemblages. This study represents the first study of coastal detritic assemblages invaded by C. racemosa var. cylindracea.

  12. Developing thresholds of potential concern for invasive alien species: Hypotheses and concepts

    Directory of Open Access Journals (Sweden)

    Llewellyn C. Foxcroft

    2009-01-01

    Full Text Available The Kruger National Park (KNP has developed and refined a system of management called ‘strategic adaptive management’ (SAM, which rests on the concept of ‘threshold of potential concern’ (TPC. TPCs represent end-points in a continuum of change. When thresholds are reached – at which point concerns of negative impacts on biodiversity are raised – management options are explicitly considered and implemented. This paper describes the TPCs developed for monitoring and managing invasive alien species (IAS. More importantly, however, it describes the conceptual understanding, principles and hypotheses adopted as the foundations for setting these TPCs. In accordance with adaptive management practices, the TPCs will be revised as the ecological and conceptual understanding of invasions grows and information is gained through research in the KNP and elsewhere.Conservation implication: In accepting that species and systems are variable, and that flux is inevitable and desirable, these TPCs developed for invasive alien species specifi cally, provide end points against which monitoring can be assessed. Once a threshold is reached, the cause of the threshold being exceeded is examined and management interventions recommended.

  13. Control of sperm concentration is necessary for standardization of sperm cryopreservation in aquatic species: evidence from sperm agglutination in oysters.

    Science.gov (United States)

    Dong, Qiaoxiang; Huang, Changjiang; Tiersch, Terrence R

    2007-02-01

    A lack of standardization in sperm cryopreservation of aquatic organisms is one of the main reasons for inconsistency observed among various studies. In particular, there have been few attempts to standardize sperm concentration during procedural optimization. This study was intended to call attention to sperm concentration standardization through research of sperm agglutination in Pacific oysters Crassostrea gigas. Sperm agglutination after thawing is a relatively frequent phenomenon observed for various aquatic species, especially when sub-optimal cryopreservation protocols are used; however, no systematic attempts have been made to explain this phenomenon. The present study evaluated various factors affecting sperm agglutination of thawed samples from diploid and tetraploid Pacific oysters, and is the first detailed report addressing the sperm agglutination phenomenon of thawed samples from any aquatic organism. Agglutination of oyster sperm was classified into six levels with a scale ranging from 0 (homogenous suspension) to 5 (well-developed "noodles"). It was found that agglutination in thawed samples was mainly due to the lack of sufficient cryoprotectant for a specific sperm concentration. Interestingly, high levels of agglutination did not necessarily lead to low fertilization. On the contrary, some sperm cells appeared to gain protection from the formation of peripheral agglutination within 0.5-ml French straws. The exact mechanism of sperm agglutination remains unclear. However, morphological examination of cross sections of the noodles (agglutination level 5) indicated at least two forms of agglutination (formed with and without cryoprotectant) which could be used as a tool to understand the cryopreservation process within the micro-environment of the straw. Furthermore, the fact that the level of sperm agglutination was directly determined by sperm concentration, in addition to the type of cryoprotectant, cryoprotectant concentration, and cooling and

  14. Discrimination of Species and Hybrid Detection in Myriophyllum Spp.: an Introduction to Biodiversity Conservation and Invasion Avoidance

    Directory of Open Access Journals (Sweden)

    R Ghahramanzadeh

    2014-03-01

    Full Text Available Minimizing economical loss through introduction of invasive alien species (IAS in local ecosystem is one of the most important issues in biosecurity. The hybridization potential between non-indigenous and native species has raised concerns due mainly to introgression, which can cause extirpation of native species through gene contamination. In the present study, 71 samples belonging to 12 species from Myriophyllum genus were assessed in Plant Breeding group of Wageningen University. Internal transcribed spacer (ITS was used for identification of invasive species from related native and possible hybrid plants. The result showed that based on universal application, high sequence divergence and species discrimination, ITS is a powerful sequence for the identification of invasive species from related non-invasive foreign and native species. In contrast to morphological data, ITS grouped suspected hybrid plants in to M. heterophyllum and demonstrated that they have not resulted from hybridization. These observations suggest that multiple introduction and genetic recombination among different introduced genotypes or genetic pools could be reasons of non-flowering in suspected hybrid plants. Results showed that molecular markers enable to distinguish invasive plant species from their most closely related congeners. This could be helpful with enforcing a ban on important of such invasive which can help to plant ecosystem and biodiversity stability.

  15. Spatial and temporal relationships between the invasive snail Bithynia tentaculata and submersed aquatic vegetation in Pool 8 of the Upper Mississippi River

    Science.gov (United States)

    Weeks, Alicia M.; DeJager, Nathan R.; Haro, Roger J.; Sandland, Greg J.

    2017-01-01

    Bithynia tentaculata is an invasive snail that was first reported in Lake Michigan in 1871 and has since spread throughout a number of freshwater systems of the USA. This invasion has been extremely problematic in the Upper Mississippi River as the snails serve as intermediate hosts for several trematode parasites that have been associated with waterfowl mortality in the region. This study was designed to assess the abundance and distribution of B. tentaculata relative to submersed aquatic vegetation as macrophytes provide important nesting and food resources for migrating waterfowl. Temporal changes in both vegetation and snail densities were compared between 2007 and 2015. Between these years, B. tentaculata densities have nearly quadrupled despite minor changes in vegetation abundance, distribution and composition. Understanding the spatial distribution of B. tentaculata in relation to other habitat features, including submersed vegetation, and quantifying any further changes in the abundance and distribution of B. tentaculata over time will be important for better identifying areas of risk for disease transmission to waterfowl.

  16. European hare Lepus europaeus(Lagomorpha: Leporidae an invasive species in Peru

    Directory of Open Access Journals (Sweden)

    Horacio Zeballos

    2013-06-01

    Full Text Available We describe the current distribution of the European hare, Lepus europaeus, in Peru which currently covers the highlands, Andean valleys, surrounding areas of the Titicaca Lake and coastal irrigations; in Arequipa, Cusco, Moquegua, Puno and Tacna departments. Based on its current distribution we developed models of potential distribution of this species, which would forecast this species in northern Peru. We make recommendations on the main issues that should be studied in Peru, and the possible consequences of their invasive process of in Peru.

  17. New invasive species of aphids (Hemiptera, Aphididae in Serbia and Montenegro

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    Petrović-Obradović Olivera

    2010-01-01

    Full Text Available Three new invasive species of aphids have been found in Serbia: Chaitophorus populifolli Essig, Myzocallis walshii (Monell and Trichosiphonaphis polygonifoliae (Shinji and two have been found in Montenegro: Aphis illinoisensis Shimer and Tinocallis kahawaluokalani (Kirkaldy. A. illinoisensis is a pest of the grapevine, T. polygonifoliae, feeds on a decorative shrub (Lonicera and the other three feed on trees (Populus, Quercus and Lagerostroemia. Three of the species are American aphids and two are of Asian origin. Their morphology, illustrated by original drawings and data on the biology and distribution are given. .

  18. USGS Nonindigenous Aquatic Species database with a focus on the introduced fishes of the lower Tennessee and Cumberland drainages

    Science.gov (United States)

    Fuller, Pam L.; Cannister, Matthew; Johansen, Rebecca; Estes, L. Dwayne; Hamilton, Steven W.; Barrass, Andrew N.

    2013-01-01

    The Nonindigenous Aquatic Species (NAS) database (http://nas.er.usgs.gov) functions as a national repository and clearinghouse for occurrence data for introduced species within the United States. Included is locality information on over 1,100 species of vertebrates, invertebrates, and vascular plants introduced as early as 1850. Taxa include foreign (exotic) species and species native to North America that have been transported outside of their natural range. Locality data are obtained from published and unpublished literature, state, federal and local monitoring programs, museum accessions, on-line databases, websites, professional communications and on-line reporting forms. The NAS web site provides immediate access to new occurrence records through a real-time interface with the NAS database. Visitors to the web site are presented with a set of pre-defined queries that generate lists of species according to state or hydrologic basin of interest. Fact sheets, distribution maps, and information on new occurrences are updated as new records and information become available. The NAS database allows resource managers to learn of new introductions reported in their region or nearby regions, improving response time. Conversely, managers are encouraged to report their observations of new occurrences to the NAS database so information can be disseminated to other managers, researchers, and the public. In May 2004, the NAS database incorporated an Alert System to notify registered users of new introductions as part of a national early detection/rapid response system. Users can register to receive alerts based on geographic or taxonomic criteria. The NAS database was used to identify 23 fish species introduced into the lower Tennessee and Cumberland drainages. Most of these are sport fish stocked to support fisheries, but the list also includes accidental and illegal introductions such as Asian Carps, clupeids, various species popular in the aquarium trade, and Atlantic

  19. Fish species of greatest conservation need in wadeable Iowa streams: current status and effectiveness of Aquatic Gap Program distribution models

    Science.gov (United States)

    Sindt, Anthony R.; Pierce, Clay; Quist, Michael C.

    2012-01-01

    Effective conservation of fish species of greatest conservation need (SGCN) requires an understanding of species–habitat relationships and distributional trends. Thus, modeling the distribution of fish species across large spatial scales may be a valuable tool for conservation planning. Our goals were to evaluate the status of 10 fish SGCN in wadeable Iowa streams and to test the effectiveness of Iowa Aquatic Gap Analysis Project (IAGAP) species distribution models. We sampled fish assemblages from 86 wadeable stream segments in the Mississippi River drainage of Iowa during 2009 and 2010 to provide contemporary, independent fish species presence–absence data. The frequencies of occurrence in stream segments where species were historically documented varied from 0.0% for redfin shiner Lythrurus umbratilis to 100.0% for American brook lampreyLampetra appendix, with a mean of 53.0%, suggesting that the status of Iowa fish SGCN is highly variable. Cohen's kappa values and other model performance measures were calculated by comparing field-collected presence–absence data with IAGAP model–predicted presences and absences for 12 fish SGCN. Kappa values varied from 0.00 to 0.50, with a mean of 0.15. The models only predicted the occurrences of banded darterEtheostoma zonale, southern redbelly dace Phoxinus erythrogaster, and longnose daceRhinichthys cataractae more accurately than would be expected by chance. Overall, the accuracy of the twelve models was low, with a mean correct classification rate of 58.3%. Poor model performance probably reflects the difficulties associated with modeling the distribution of rare species and the inability of the large-scale habitat variables used in IAGAP models to explain the variation in fish species occurrences. Our results highlight the importance of quantifying the confidence in species distribution model predictions with an independent data set and the need for long-term monitoring to better understand the

  20. Tolerance and resistance of invasive and native Eupatorium species to generalist herbivore insects

    Science.gov (United States)

    Wang, Rui-Fang; Feng, Yu-Long

    2016-11-01

    Invasive plants are exotic species that escape control by native specialist enemies. However, exotic plants may still be attacked by locally occurring generalist enemies, which can influence the dynamics of biological invasions. If invasive plants have greater defensive (resistance and tolerance) capabilities than indigenous plants, they may experience less damage from native herbivores. In the present study, we tested this prediction using the invasive plant Eupatorium adenophorum and two native congeners under simulated defoliation and generalist herbivore insect (Helicoverpa armigera and Spodoptera litura) treatments. E. adenophorum was less susceptible and compensated more quickly to damages in biomass production from both treatments compared to its two congeners, exhibiting greater herbivore tolerance. This strong tolerance to damage was associated with greater resource allocation to aboveground structures, leading to a higher leaf area ratio and a lower root: crown mass ratio than those of its native congeners. E. adenophorum also displayed a higher resistance index (which integrates acid detergent fiber, nitrogen content, carbon/nitrogen ratio, leaf mass per area, toughness, and trichome density) than its two congeners. Thus, H. armigera and S. litura performed poorly on E. adenophorum, with less leaf damage, a lengthened insect developmental duration, and decreased pupating: molting ratios compared to those of the native congeners. Strong tolerance and resistance traits may facilitate the successful invasion of E. adenophorum in China and may decrease the efficacy of leaf-feeding biocontrol agents. Our results highlight both the need for further research on defensive traits and their role in the invasiveness and biological control of exotic plants, and suggest that biocontrol of E. adenophorum in China would require damage to the plant far in excess of current levels.

  1. Diel flight behaviour and dispersal patterns of aquatic Coleoptera and Heteroptera species with special emphasis on the importance of seasons

    Science.gov (United States)

    Csabai, Zoltán; Kálmán, Zoltán; Szivák, Ildikó; Boda, Pál

    2012-09-01

    Dispersal flight is the most important and almost the only way for primary aquatic insects to find new water habitats. During a 30-week-long project, we monitored the flight dispersal behaviour of aquatic beetles and bugs with using highly and horizontally polarizing agricultural black plastic sheets laid onto the ground. Based on the flight data of more than 45,000 individuals and 92 species, we explored and described eight different diel flight activity patterns. We found that seven of eight dispersal patterns are consistent with the previous knowledge, while three conspicuous mass dispersal periods can be identified as in the mid morning and/or around noon and/or at nightfall. As an exception, we found a `daytime' pattern occurred exclusively in spring, in which mass dispersal can be seen from mid morning to late afternoon. In contrast to previous studies, we emphasize here that the seasonality has to be considered in evaluation of the diurnal flight activity. According to the seasons, a `three code sign' was proposed to indicate the diel dispersal flight behaviour of a species for a year. Most of the species utilize different diel activity patterns in different seasons. In spring, the daytime pattern was the preferred type, but in summer and autumn, the evening types were the most popular patterns. We stated that the seasonal change of air temperature has a crucial role in that a pattern could be manifested in a given season or not and brings a need to change the diel dispersal pattern among seasons.

  2. Disruption of foraging by a dominant invasive species to decrease its competitive ability.

    Science.gov (United States)

    Westermann, Fabian Ludwig; Suckling, David Maxwell; Lester, Philip John

    2014-01-01

    Invasive species are a major threat to biodiversity when dominant within their newly established habitat. The globally distributed Argentine ant Linepithema humile has been reported to break the trade-off between interference and exploitative competition, achieve high population densities, and overpower nests of many endemic ant species. We have used the sensitivity of the Argentine ant to the synthetic trail pheromone (Z)-9-hexadecanal to investigate species interactions for the first time. We predicted that disrupting Argentine ant trail following behaviour would reduce their competitive ability and create an opportunity for three other resident species to increase their foraging success. Argentine ant success in the control was reduced with increasing pheromone concentration, as predicted, but interactions varied among competing resident species. These behavioural variations provide an explanation for observed differences in foraging success of the competing resident species and how much each of these individual competitors can increase their foraging if the competitive ability of the dominant invader is decreased. The mechanism for the observed increase in resource acquisition of resident species appears to be a decrease in aggressive behaviour displayed by the Argentine ant, which may create an opportunity for other resident species to forage more successfully. Our demonstration of species interactions with trail pheromone disruption is the first known case of reduced dominance under a pheromone treatment in ants.

  3. Bacterial infections from aquatic species: potential for and prevention of contact zoonoses.

    Science.gov (United States)

    Haenen, O L M; Evans, J J; Berthe, F

    2013-08-01

    As aquaculture production and the consumption of aquaculture products increase, the possibility of contracting zoonotic infections from either handling or ingesting these products also increases. The principal pathogens acquired topically from fish or shellfish through spine/pincer puncture or open wounds are Aeromonas hydrophila, Edwardsiella tarda, Mycobacterium marinum, Streptococcus iniae, Vibrio vulnificus and V. damsela. These pathogens, which are all indigenous to the aquatic environment, have also been associated with disease outbreaks in food fish. Outbreaks are often related to management factors, such as the quality and quantity of nutrients in the water and high stocking density, which can increase bacterial loads on the external surface of the fish. As a result, diseased fish are more likely to transmit infection to humans. This review provides an account of human cases of zoonoses throughout the world from the principal zoonotic pathogens of fish and shellfish.

  4. A numerical taxonomic study of species of Vibrio isolated from the aquatic environment and birds in Kent, England.

    Science.gov (United States)

    West, P A; Lee, J V; Bryant, T N

    1983-10-01

    A numerical taxonomic study has been carried out to confirm the identity of strains of the family Vibrionaceae isolated during an ecological study. A total of 237 strains were studied including 148 from the aquatic environment, 6 from estuarine birds, 1 from sheep faeces, and 61 control cultures. Duplicates of 21 of the strains were randomly selected and included to estimate test and operator error. Taxonomic resemblance was estimated on the basis of 148 characters using Euclidean distance. The taxonomic position of some strains was reevaluated using the pattern different coefficient. Strains were clustered by three methods, all of which gave similar results. The estimated average probability of test error was 1.5%. Strains previously identified as Vibrio anguillarum fell into four distinct phenons corresponding to V. anguillarum biovar I, 'V. anguillarum biovar II', V. diazotrophicus, and strains pathogenic to oyster larvae. The latter group characteristically degraded xanthine and probably represents a new species. The phenon corresponding to V. cholerae included the type strain, strains of human origin, and strains isolated in the United Kingdom from birds and the aquatic environment. Some strains of V. cholerae were luminous. Other phenons were identified as V. metschnikovii, V. fluvialis, and Aeromonas spp.

  5. Nuclear microscopy as a tool in TiO2 nanoparticles bioaccumulation studies in aquatic species

    Science.gov (United States)

    Pinheiro, Teresa; Moita, Liliana; Silva, Luís; Mendonça, Elsa; Picado, Ana

    2013-07-01

    Engineered Titanium nanoparticles are used for a wide range of applications from coatings, sunscreen cosmetic additives to solar cells or water treatment agents. Inevitably environmental exposure can be expected and data on the ecotoxicological evaluation of nanoparticles are still scarce. The potential effects of nanoparticles of titanium dioxide (TiO2) on two model organisms, the water flea, Daphnia magna and the duckweed Lemna minor, were examined in semichronic toxicity tests. Daphnia and Lemna were exposed to TiO2 nanoparticles (average particle size value of 28 ± 11 nm (n = 42); concentration range, 1.4-25 mg/L) by dietary route and growth in medium containing the nanoparticles of TiO2, respectively. Both morphology and microdistribution of Ti in the individuals were examined by nuclear microscopy techniques. A significant amount of TiO2 was found accumulated in Daphnia exposed to nanoparticles. Nuclear microscopy imaging revealed that Ti was localized only in the digestive tract of the Daphnia, which displayed difficulty in eliminating the nanoparticles from their body. Daphnia showed higher mortality when exposed to higher concentrations of TiO2 (>10 mg/L). The exposure to TiO2 nanoparticles above 25 mg/L caused morphological alterations in Lemna. The roots became stiff and fronds colorless. The Ti mapping of cross-sections of roots and fronds showed that Ti was mainly deposited in the epidermis of the fronds and roots, with minor internalization. In summary, exposure of aquatic organisms to TiO2 nanoparticles may alter the physiology of these organisms at individual and population levels, posing risks to aquatic ecosystems.

  6. Litter mixture dominated by leaf litter of the invasive species, Flaveria bidentis, accelerates decomposition and favors nitrogen release.

    Science.gov (United States)

    Li, Huiyan; Wei, Zishang; Huangfu, Chaohe; Chen, Xinwei; Yang, Dianlin

    2017-01-01

    In natural ecosystems, invasive plant litter is often mixed with that of native species, yet few studies have examined the decomposition dynamics of such mixtures, especially across different degrees of invasion. We conducted a 1-year litterbag experiment using leaf litters from the invasive species Flaveria bidentis (L.) and the dominant co-occurring native species, Setaria viridis (L.). Litters were allowed to decompose either separately or together at different ratios in a mothproof screen house. The mass loss of all litter mixtures was non-additive, and the direction and strength of effects varied with species ratio and decomposition stage. During the initial stages of decomposition, all mixtures had a neutral effect on the mass loss; however, at later stages of decomposition, mixtures containing more invasive litter had synergistic effects on mass loss. Importantly, an increase in F. bidentis litter with a lower C:N ratio in mixtures led to greater net release of N over time. These results highlight the importance of trait dissimilarity in determining the decomposition rates of litter mixtures and suggest that F. bidentis could further synchronize N release from litter as an invasion proceeds, potentially creating a positive feedback linked through invasion as the invader outcompetes the natives for nutrients. Our findings also demonstrate the importance of species composition as well as the identity of dominant species when considering how changes in plant community structure influence plant invasion.

  7. Invasive rats on tropical islands: Their population biology and impacts on native species

    Directory of Open Access Journals (Sweden)

    Grant A. Harper

    2015-01-01

    Full Text Available The three most invasive rat species, black or ship rat Rattus rattus, brown or Norway rats, R. norvegicus and Pacific rat, R. exulans have been incrementally introduced to islands as humans have explored the world’s oceans. They have caused serious deleterious effects through predation and competition, and extinction of many species on tropical islands, many of which are biodiversity hotspots. All three rat species are found in virtually all habitat types, including mangrove and arid shrub land. Black rats tend to dominate the literature but despite this the population biology of invasive rats, particularly Norway rats, is poorly researched on tropical islands. Pacific rats can often exceed population densities of well over 100 rats ha−1 and black rats can attain densities of 119 rats ha−1, which is much higher than recorded on most temperate islands. High densities are possibly due to high recruitment of young although the data to support this are limited. The generally aseasonally warm climate can lead to year-round breeding but can be restricted by either density-dependent effects interacting with resource constraints often due to aridity. Apparent adverse impacts on birds have been well recorded and almost all tropical seabirds and land birds can be affected by rats. On the Pacific islands, black rats have added to declines and extinctions of land birds caused initially by Pacific rats. Rats have likely caused unrecorded extinctions of native species on tropical islands. Further research required on invasive rats on tropical islands includes the drivers of population growth and carrying capacities that result in high densities and how these differ to temperate islands, habitat use of rats in tropical vegetation types and interactions with other tropical species, particularly the reptiles and invertebrates, including crustaceans.

  8. The adaptational strategies of the hindlimb muscles in the Tenrecidae species including the aquatic web-footed tenrec (Limnogale mergulus).

    Science.gov (United States)

    Endo, Hideki; Yonezawa, Takahiro; Rakotondraparany, Felix; Sasaki, Motoki; Hasegawa, Masami

    2006-07-01

    The hindlimb muscles in four species of Tenrecidae (Oryzoryctinae: Talazac long-tailed tenrec and web-footed tenrec, Tenrecinae: lesser hedgehog tenrec, and streaked tenrec), were examined macroscopically. The weight ratios of the muscles to the body in the oryzoryctinid species are larger than those in Tenrecinae, since the Oryzoryctinae species have an obviously smaller body from the evolutionary point of view. It can be primarily pointed out that the adaptation of the body size is different between the two subfamilies, and secondarily, that functional adaptation to locomotion is complete within each subfamily. The weight data and the morphological findings demonstrate that the web-footed tenrec possesses an extraordinary large M. semimembranosus in comparison to the Talazac long-tailed tenrec in their weight ratios. This muscle may act as a strong flexor motor in the knee joint during the aquatic locomotion of the web-footed tenrec. Since the other muscles of the web-footed tenrec are similar to those of the Talazac long-tailed tenrec regards weight ratio data, we think that the web-footed tenrec may have derived from a terrestrial ancestor such as the long-tailed tenrecs. In Tenrecinae the streaked tenrec is equipped with larger Mm. adductores, M. semimembranosus and M. triceps surae than the lesser hedgehog tenrec. This species is adapted to fossorial life derived from non-specialized ancestors within the evolutionary lines of the spiny tenrecs.

  9. Invasive plant species alters consumer behavior by providing refuge from predation.

    Science.gov (United States)

    Dutra, Humberto P; Barnett, Kirk; Reinhardt, Jason R; Marquis, Robert J; Orrock, John L

    2011-07-01

    Understanding the effects of invasive plants on native consumers is important because consumer-mediated indirect effects have the potential to alter the dynamics of coexistence in native communities. Invasive plants may promote changes in consumer pressure due to changes in protective cover (i.e., the architectural complexity of the invaded habitat) and in food availability (i.e., subsidies of fruits and seeds). No experimental studies have evaluated the relative interplay of these two effects. In a factorial experiment, we manipulated cover and food provided by the invasive shrub Amur honeysuckle (Lonicera maackii) to evaluate whether this plant alters the foraging activity of native mammals. Using tracking plates to quantify mammalian foraging activity, we found that removal of honeysuckle cover, rather than changes in the fruit resources it provides, reduced the activity of important seed consumers, mice in the genus Peromyscus. Two mesopredators, Procyon lotor and Didelphis virginiana, were also affected. Moreover, we found rodents used L. maackii for cover only on cloudless nights, indicating that the effect of honeysuckle was weather-dependent. Our work provides experimental evidence that this invasive plant species changes habitat characteristics, and in so doing alters the behavior of small- and medium-sized mammals. Changes in seed predator behavior may lead to cascading effects on the seeds that mice consume.

  10. Membrane filtration studies of aquatic humic substances and their metal species: a concise overview. Part 2. Evaluation of conditional stability constants by using ultrafiltration.

    Science.gov (United States)

    Nifant'eva, T I; Shkinev, V M; Spivakov, B Y; Burba, P

    1999-02-01

    The assessment of conditional stability constants of aquatic humic substance (HS) metal complexes is overviewed with special emphasis on the application of ultrafiltration methods. Fundamentals and limitations of stability functions in the case of macromolecular and polydisperse metal-HS species in aquatic environments are critically discussed. The review summarizes the advantages and application of ultrafiltration for metal-HS complexation studies, discusses the comparibility and reliability of stability constants. The potential of ultrafiltration procedures for characterizing the lability of metal-HS species is also stressed.

  11. Inventory of Invasive Plant Species along the corridor of Kawah Ijen Nature Tourism Park, Banyuwangi, East Java

    Directory of Open Access Journals (Sweden)

    Lia Hapsari

    2014-01-01

    Full Text Available A field survey was conducted in November 2013 to inventory invasive plant species present along the corridor of Kawah Ijen Nature Tourism Park exploratively. Result showed that there were 11 plant species found abundantly along the corridor. Typical native species were dominated by Cyathea contaminans, Casuarina junghuhniana and Vaccinium varingiaefolium. Three species were determined as invasive alien species i.e. Chromolaena odorata, Acacia decurrens and Blumea lacera whereas five species were determined as native species but potential invaders i.e. Rubus moluccanus, Melastoma malabatrichum, Polygonum barbatum, Debregeasia longifolia and Pteridium aquilinum. In term of tourism particularly on nature-based destinations enable moving in and out of invasive alien species due to opening the access of some natural protected areas. The environmental impact of an alien species whether it becomes invasive at its destination depends on its biological key point,  what ecological role the species may play, and on additional factors such as its tolerance of the gross features of the environment in the new range. Keyword: invasive plants, corridor, Kawah Ijen, Nature Tourism Park, Banyuwangi

  12. Predicting climate change impacts on native and invasive tree species using radial growth and twenty-first century climate scenarios

    NARCIS (Netherlands)

    González-Muñoz, N.; Linares, J.C.; Castro-Díez, P.; Sass-Klaassen, U.G.W.

    2014-01-01

    The climatic conditions predicted for the twenty-first century may aggravate the extent and impacts of plant invasions, by favouring those invaders more adapted to altered conditions or by hampering the native flora. We aim to predict the fate of native and invasive tree species in the oak forests o

  13. From restoration to adaptation: the changing discourse of invasive species management in coastal New England under global environmental change

    Science.gov (United States)

    Scholars have focused on militaristic metaphors of invasion for more than a decade, but few if any studies look to the on-the-ground language of restoration practitioners to determine how they talk about invasive species. Here we demonstrate the absence of militaristic metaphors ...

  14. Synthesis and insecticidal activity of acridone derivatives to Aedes aegypti and Culex quinquefasciatus larvae and non-target aquatic species

    Science.gov (United States)

    Roopan, Selvaraj Mohana; Bharathi, Annadurai; Al-Dhabi, Naif Abdullah; Arasu, Mariadhas Valan; Madhumitha, G.

    2017-01-01

    A serious Mosquito borne yellow fever is one of the grave diseases which affect the major population. Since there is no specific treatment for yellow fever, there is a necessity to develop an effective agent. The series of acridinone analogues 3 to 5 were synthesized with help of non-conventional microwave heating and confirmed by respective spectral characterization. 5c and 3b showed highest activity to kill 90% of larvae against A. aegypti and C. quinquefasciatus, respectively. Also the active products were treated to check the mortality of non-target aquatic species. Through the reports of the larvicidal bioassay, compounds 3b against C. quinquefasciatus whereas 5c against A. aegypti were found to be more active. By keeping this as a platform, further extension of the work can be done to find out a valuable drug for controlling disease vectors.

  15. Comparing climate change and species invasions as drivers of coldwater fish population extirpations.

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    Sapna Sharma

    Full Text Available Species are influenced by multiple environmental stressors acting simultaneously. Our objective was to compare the expected effects of climate change and invasion of non-indigenous rainbow smelt (Osmerus mordax on cisco (Coregonus artedii population extirpations at a regional level. We assembled a database of over 13,000 lakes in Wisconsin, USA, summarising fish occurrence, lake morphology, water chemistry, and climate. We used A1, A2, and B1 scenarios from the Intergovernmental Panel on Climate Change (IPCC of future temperature conditions for 15 general circulation models in 2046-2065 and 2081-2100 totalling 78 projections. Logistic regression indicated that cisco tended to occur in cooler, larger, and deeper lakes. Depending upon the amount of warming, 25-70% of cisco populations are predicted to be extirpated by 2100. In addition, cisco are influenced by the invasion of rainbow smelt, which prey on young cisco. Projecting current estimates of rainbow smelt spread and impact into the future will result in the extirpation of about 1% of cisco populations by 2100 in Wisconsin. Overall, the effect of climate change is expected to overshadow that of species invasion as a driver of coldwater fish population extirpations. Our results highlight the potentially dominant role of climate change as a driver of biotic change.

  16. Spatially explicit control of invasive species using a reaction-diffusion model

    Science.gov (United States)

    Bonneau, Mathieu; Johnson, Fred A.; Romagosa, Christina M.

    2016-01-01

    Invasive species, which can be responsible for severe economic and environmental damages, must often be managed over a wide area with limited resources, and the optimal allocation of effort in space and time can be challenging. If the spatial range of the invasive species is large, control actions might be applied only on some parcels of land, for example because of property type, accessibility, or limited human resources. Selecting the locations for control is critical and can significantly impact management efficiency. To help make decisions concerning the spatial allocation of control actions, we propose a simulation based approach, where the spatial distribution of the invader is approximated by a reaction–diffusion model. We extend the classic Fisher equation to incorporate the effect of control both in the diffusion and local growth of the invader. The modified reaction–diffusion model that we propose accounts for the effect of control, not only on the controlled locations, but on neighboring locations, which are based on the theoretical speed of the invasion front. Based on simulated examples, we show the superiority of our model compared to the state-of-the-art approach. We illustrate the use of this model for the management of Burmese pythons in the Everglades (Florida, USA). Thanks to the generality of the modified reaction–diffusion model, this framework is potentially suitable for a wide class of management problems and provides a tool for managers to predict the effects of different management strategies.

  17. Dispersal and selection mediate hybridization between a native and invasive species.

    Science.gov (United States)

    Kovach, Ryan P; Muhlfeld, Clint C; Boyer, Matthew C; Lowe, Winsor H; Allendorf, Fred W; Luikart, Gordon

    2015-01-22

    Hybridization between native and non-native species has serious biological consequences, but our understanding of how dispersal and selection interact to influence invasive hybridization is limited. Here, we document the spread of genetic introgression between a native (Oncorhynchus clarkii) and invasive (Oncorhynchus mykiss) trout, and identify the mechanisms influencing genetic admixture. In two populations inhabiting contrasting environments, non-native admixture increased rapidly from 1984 to 2007 and was driven by surprisingly consistent processes. Individual admixture was related to two phenotypic traits associated with fitness: size at spawning and age of juvenile emigration. Fish with higher non-native admixture were larger and tended to emigrate at a younger age--relationships that are expected to confer fitness advantages to hybrid individuals. However, strong selection against non-native admixture was evident across streams and cohorts (mean selection coefficient against genotypes with non-native alleles (s) = 0.60; s.e. = 0.10). Nevertheless, hybridization was promoted in both streams by the continuous immigration of individuals with high levels of non-native admixture from other hybrid source populations. Thus, antagonistic relationships between dispersal and selection are mediating invasive hybridization between these fish, emphasizing that data on dispersal and natural selection are needed to fully understand the dynamics of introgression between native and non-native species.

  18. eDNA and specific primers for early detection of invasive species--A case study on the bivalve Rangia cuneata, currently spreading in Europe.

    Science.gov (United States)

    Ardura, Alba; Zaiko, Anastasija; Martinez, Jose L; Samulioviene, Aurelija; Semenova, Anna; Garcia-Vazquez, Eva

    2015-12-01

    Intense human activities facilitate the successful spread and establishment of non-indigenous aquatic organisms in marine and freshwater ecosystems. In some cases such intrusions result in noticeable and adverse changes in the recipient environments. In the Baltic Sea, the discovery and rapid initial spread of the North American wedge clam Rangia cuneata represents a new wave of invasion which may trigger unpredictable changes of the local benthic communities. In this study we present a species-specific DNA-based marker developed in silico and experimentally tested on environmental samples. Marker specificity and sensitivity were assessed in vitro from water samples containing different mixtures of the target species and other five bivalves currently present in the region: the native Cerastoderma glaucum, Macoma balthica and Mytilus trossulus, the invasive Dreissena polymorpha and the cryptogenic Mya arenaria. Cross-species amplification was not found in any case. The method allows to detecting at least 0.4 ng of R. cuneata DNA per μl, and 0.1 g of tissue per liter of water. Finally, the marker performance was assessed in water samples from the Baltic Sea and Vistula Lagoon. The coincidence between independent visual observations of R. cuneata and positive PCR amplification of the marker from the water samples confirmed the efficiency of this highly reproducible, fast, and technically easy method. R. cuneata traces can be detected from environmental DNA even when the population is sparse and small, enabling rapid management responses and allowing to track the invasion dynamics.

  19. Experimental Effects of Lime Application on Aquatic Macrophytes: 4. Growth Response of Three Species

    Science.gov (United States)

    2007-04-01

    James PURPOSE: This investigation examined the growth response of three macrophyte species ( Elodea canadensis, Stuckenia pectinata, and Vallisnaria...different macrophyte species. These hypotheses were tested using experimental mesocosms. METHODS: Elodea canadensis, Stuckenia pectinata, and...Snel, P. E. Zanstra, and R. J. Helder. 1982. The mechanism of bicarbonate assimilation by the polar leaves of Potamogeton and Elodea . CO2 concentrations

  20. Invasive ecosystem engineer selects for different phenotypes of an associated native species.

    Science.gov (United States)

    Wright, Jeffrey T; Gribben, Paul E; Byers, James E; Monro, Keyne

    2012-06-01

    Invasive habitat-forming ecosystem engineers modify the abiotic environment and thus represent a major perturbation to many ecosystems. Because native species often persist in these invaded habitats but have no shared history with the ecosystem engineer, the engineer may impose novel selective pressure on native species. In this study, we used a phenotypic selection framework to determine whether an invasive habitat-forming ecosystem engineer (the seaweed Caulerpa taxifolia) selects for different phenotypes of a common co-occurring native species (the bivalve Anadara trapezia). Compared to unvegetated habitat, Caulerpa habitat has lower water flow, lower dissolved oxygen, and sediments are more silty and anoxic. We determined the performance consequences of variation in key functional traits that may be affected by these abiotic changes (shell morphology, gill mass, and palp mass) for Anadara transplanted into Caulerpa and unvegetated habitat. Both linear and nonlinear performance gradients in Anadara differed between habitats, and these gradients were stronger in Caulerpa compared to unvegetated sediment. Moreover, in Caulerpa alternate phenotypes performed well, and these phenotypes were different from the dominant phenotype in unvegetated sediment. By demonstrating that phenotype-performance gradients differ between habitats, we have highlighted a role for Caulerpa as an agent of selection on native species.

  1. Disruption of ecosystem processes in western North America by invasive species

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Dukes

    2004-09-01

    Full Text Available Many ecosystems of western North America have been dramatically changed by non-native species. Here, we review ecological impacts of 56 plant, animal, fungus, and protist species that were brought to this region by humans. We discuss characteristics of invasive species that can lead to major ecosystem impacts, and explore how invasive species alter many different attributes of ecosystems. Specifically, we include examples of invasive species that affect geomorphology, fire regimes, hydrology, microclimate, atmospheric composition, nutrient cycling, and productivity. Finally, we review the direct consequences of biological invasions for some native species. We summarize examples from this paper in Appendix 1. Our examples illustrate how, as invasive species have become dominant across large areas of western North America's grassland, shrubland, dune, riparian, and estuarine ecosystems, the properties and functioning of these systems have changed. To date, some systems in this region, such as its forests, remain relatively unaffected by invasive species. However, recent attacks of forest pathogens highlight the potential vulnerability of these ecosystemsMuchos ecosistemas de Norteamérica occidental han cambiado dramáticamente a causa del efecto producido por especies no autóctonas. Aquí se muestra una revisión del impacto ecológico producido por 56 especies diferentes de plantas, animales y hongos, y especies de protistas que fueron traídos a esta región por humanos. Discutimos las características de las especies invasoras que pueden producir un gran impacto en el ecosistema, y exploramos cómo las especies invasoras pueden alterar de forma muy diferente los atributos de un ecosistema. Específicamente, incluimos ejemplos de especies invasoras que afectan a la geomorfología, a los regímenes del fuego, a la hidrología, al microclima, a la composición atmosférica, al ciclo de nutrientes, y a la productividad. Finalmente, revisamos las

  2. Transcriptome analysis and comparison reveal divergence between two invasive whitefly cryptic species

    Directory of Open Access Journals (Sweden)

    Xia Jun

    2011-09-01

    Full Text Available Abstract Background Invasive species are valuable model systems for examining the evolutionary processes and molecular mechanisms associated with their specific characteristics by comparison with closely related species. Over the past 20 years, two species of the whitefly Bemisia tabaci species complex, Middle East-Asia Minor 1 (MEAM1 and Mediterranean (MED, have both spread from their origin Middle East/Mediterranean to many countries despite their apparent differences in many life history parameters. Previously, we have sequenced the transcriptome of MED. In this study, we sequenced the transcriptome of MEAM1 and took a comparative genomic approach to investigate the transcriptome evolution and the genetic factors underlying the differences between MEAM1 and MED. Results Using Illumina sequencing technology, we generated 17 million sequencing reads for MEAM1. These reads were assembled into 57,741 unique sequences and 15,922 sequences were annotated with an E-value above 10-5. Compared with the MED transcriptome, we identified 3,585 pairs of high quality orthologous genes and inferred their sequence divergences. The average differences in coding, 5' untranslated and 3' untranslated region were 0.83%, 1.66% and 1.43%, respectively. The level of sequence divergence provides additional support to the proposition that MEAM1 and MED are two species. Based on the ratio of nonsynonymous and synonymous substitutions, we identified 24 sequences that have evolved in response to positive selection. Many of those genes are predicted to be involved in metabolism and insecticide resistance which might contribute to the divergence of the two whitefly species. Conclusions Our data present a comprehensive sequence comparison between the two invasive whitefly species. This study will provide a road map for future investigations on the molecular mechanisms underlying their biological differences.

  3. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Lee Metcalf National Wildlife Refuge, Lee Metcalf ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  4. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Swan River National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  5. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Lost Trail National Wildlife Refuge, Benton Lake & Lee Metcalf ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  6. [Montana MOYOCO Invasive Species Strike Team Final Report 2013] Charles M. Russel National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  7. [Montana MOYOCO Invasive Species Strike Team Final Report 2013] Benton Lake National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  8. Nisqually - Early Detection Rapid Response, Monitoring and Mapping of High Priority Invasive Species with Nisqually NWRC Weed Warriors 2007

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project continues a successful program of early detection and rapid response, monitoring and mapping of invasive species on Nisqually NWRC (NNWRC) by Weed...

  9. Nisqually - Early Detection Rapid Response, Monitoring and Mapping of High Priority Invasive Species with Nisqually NWRC Weed Warriors 2008

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project will continue a successful program of early detection and rapid response, monitoring and mapping of invasive species on Nisqually NWRC by Weed Warrior...

  10. Tualatin River - Implementation of a Comprehensive Survey for Invasive and Other Nonnative Plant Species on the Tualatin River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The proposed project will use GPS and GIS technology to quantitatively determine species occurrence of nonnative and invasive plants on refuge lands. Currently the...

  11. [Montana MOYOCO Invasive Species Strike Team Final Report 2013] National Elk Refuge, Teton County Weed & Pest Control District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  12. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Charles M. Russel National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  13. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] National Elk Refuge, Teton County Weed & Pest Control District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  14. The problem of assessing the viability of invasive species in the conditions of the steppe zone of Ukraine

    Directory of Open Access Journals (Sweden)

    K. K. Holoborodko

    2016-10-01

    Full Text Available This article proposes a completely new method of resolving the pressing global environmental problem of assessing the capacity of invasive organisms to adapt to new environmental conditions. A new three-step approach to the evaluation of vital and ecological functions of invasive species is recommended. In addition to classic species and population surveys, it was proposed to apply a stress-resistance biochemical assessment of invasive species. Stress resistance can be regarded as the main response of living organisms to changes in continuous environmental components. The obtained results will provide an opportunity to give a qualitative prognisis of what adaptive capacity an invasive species has,what precise ecological functions and for what time period it can perform in a new ecosystem.

  15. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Red Rock Lakes National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO (MT) Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  16. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Medicine Lake National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO (MT) Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  17. [Montana MOYOCO Invasive Species Strike Team Final Report 2014] Benton Lake National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO MT Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered by...

  18. [Montana MOYOCO Invasive Species Strike Team Final Report 2013] Medicine Lake National Wildlife Refuge, Benton Lake ISST

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The MOYOCO (MT) Invasive Species Strike Team is made up of two field strike teams, housed at Benton Lake and Lee Metcalf National Wildlife Refuges, yet administered...

  19. Gone with the wind and the stream: Dispersal in the invasive species Ailanthus altissima

    Science.gov (United States)

    Planchuelo, Greg; Catalán, Pablo; Delgado, Juan Antonio

    2016-05-01

    Dispersal is a key process in plant invasions and is strongly related to diaspore morphology. Often, dispersal comprises more than one step, and morphologies adapted to a primary dispersal mechanism can aid or detract from a secondary one. The aim of this work was to assess the relationship between primary wind dispersal and secondary water dispersal in Ailanthus altissima, an invasive tree species. Wind and water dispersal potential and their association with the morphological characteristics of samaras were assessed under controlled conditions to ensure the repeatability of the measurements. We found a direct positive relationship between primary wind and secondary water dispersal in A. altissima. The main morphological characteristics of the samara that affected the success of the two types of dispersal were side perimeter and mass. However, a possibility of dispersal specialisation exists, as one morphological characteristic (samara width) affects wind dispersal negatively but water dispersal positively, and dispersal potential and samara morphology have been shown to differ across individuals.

  20. Effects of High Temperature and Water Stress on Seed Germination of the Invasive Species Mexican Sunflower.

    Science.gov (United States)

    Wen, Bin

    2015-01-01

    Mexican sunflower is native to Mexico and Central America and was introduced into China early last century. Now it has widely naturalized and is exhibiting increasing invasiveness in South China. As this species often dominates bare ground, a habitat characterized by extreme fluctuation in temperature and water, it is reasonable to hypothesize that it has special adaptations to high temperature and water stress. Using laboratory experiments to simulate these stresses, this study investigated the response of Mexican sunflower seed germination to temperature and water stress, and compared these responses with those previously reported for another invasive, bamboo piper, which is confined to relatively cool and moist habitats in Xishuangbanna. As expected, Mexican sunflower seeds exhibited higher tolerance to these stresses than bamboo piper. Germination of Mexican sunflower seeds was highest at 15-30°C, but significant numbers of seeds germinated and formed seedlings at 10°C and 35°C, at which no bamboo piper seeds formed seedlings, indicating a wider temperature range for germination than the latter. Roughly half the seeds survived 240 h continuous heat treatment and up to 15 h daily periodical heat treatment at 40°C, while bamboo piper seeds were mostly killed by these treatments. About 20% of Mexican sunflower but no bamboo piper seeds germinated after heat treatment for 30 min at 80°C. Germination was completely inhibited in bamboo piper seeds at -0.6 mPa, while 20-60% of Mexican sunflower seeds germinated depending on PEG or NaCl as osmoticum. This higher tolerance in Mexican sunflower seeds accords with its stronger invasiveness in this area. This comparison between two plant invaders demonstrates that invasiveness is not an all-or-nothing situation, and that adaptation to local habitats is a critical determinant of successful invasiveness for an alien plant.

  1. Retracing the routes of introduction of invasive species: the case of the Sirex noctilio woodwasp.

    Science.gov (United States)

    Boissin, E; Hurley, B; Wingfield, M J; Vasaitis, R; Stenlid, J; Davis, C; de Groot, P; Ahumada, R; Carnegie, A; Goldarazena, A; Klasmer, P; Wermelinger, B; Slippers, B

    2012-12-01

    Understanding the evolutionary histories of invasive species is critical to adopt appropriate management strategies, but this process can be exceedingly complex to unravel. As illustrated in this study of the worldwide invasion of the woodwasp Sirex noctilio, population genetic analyses using coalescent-based scenario testing together with Bayesian clustering and historical records provide opportunities to address this problem. The pest spread from its native Eurasian range to the Southern Hemisphere in the 1900s and recently to Northern America, where it poses economic and potentially ecological threats to planted and native Pinus spp. To investigate the origins and pathways of invasion, samples from five continents were analysed using microsatellite and sequence data. The results of clustering analysis and scenario testing suggest that the invasion history is much more complex than previously believed, with most of the populations being admixtures resulting from independent introductions from Europe and subsequent spread among the invaded areas. Clustering analyses revealed two major source gene pools, one of which the scenario testing suggests is an as yet unsampled source. Results also shed light on the microevolutionary processes occurring during introductions, and showed that only few specimens gave rise to some of the populations. Analyses of microsatellites using clustering and scenario testing considered against historical data drastically altered our understanding of the invasion history of S. noctilio and will have important implications for the strategies employed to fight its spread. This study illustrates the value of combining clustering and ABC methods in a comprehensive framework to dissect the complex patterns of spread of global invaders.

  2. Complex interactions between regional dispersal of native taxa and an invasive species.

    Science.gov (United States)

    Strecker, Angela L; Arnott, Shelley E

    2010-04-01

    In the event of an environmental disturbance, dispersal of native taxa may provide species and genetic diversity to ecosystems, increasing the likelihood that there will be species and genotypes present that are less vulnerable to the disturbance. This may allow communities to maintain functioning during a disturbance and may be particularly important when the perturbation is novel to the system, such as the establishment of an invasive species. We examined how dispersal of native species may influence crustacean zooplankton communities in freshwater lakes invaded by the invertebrate predator, Bythotrephes longimanus. Using large enclosures, we experimentally tested the effect of dispersal on zooplankton community abundance, richness, and composition in (1) a community invaded by Bythotrephes, (2) the same community with the invader removed, and (3) a community that was never invaded. Dispersal increased zooplankton community abundance and richness; however, these effects were usually only significant in the invader-removed treatment. Dispersal tended to make the invader-removed communities more similar to never-invaded communities in abundance, richness, and composition. Dispersal had little effect on zooplankton abundance in the invaded community; however, richness significantly increased, and the community composition changed to resemble a never-invaded community by the end of the experiment. Our results have implications for understanding the role of dispersal during transitory states in communities. Dispersal of native taxa may be particularly important during the period between the arrival and broad-scale establishment of Bythotrephes, as dispersal through space or time (i.e., from resting eggs) may rapidly increase zooplankton abundance when the invader is absent or in low abundances. Overall, our results suggest that communities with strong local predatory and competitive interactions may be closed to immigration from colonists, but that invasive species

  3. TiO2 as a photocatalyst for control of the aquatic invasive alga, Cladophora, under natural and artificial light

    Science.gov (United States)

    Peller, J.R.; Whitman, R.L.; Griffith, S.; Harris, P.; Peller, C.; Scalzitti, J.

    2007-01-01

    Cladophora, a nuisance and invasive, filamentous algae (Chlorophyta), massively accumulates along the shores of the lower Great Lakes each summer causing great economic damage and compromising recreational opportunity and perhaps public health. In vitro experiments showed that Cladophora samples were physically and biologically degraded when subjected to TiO2-mediated photocatalysis. For the most successful photocatalytic process, TiO2 was immobilized on a glass surface and used in combination with either sunlight or artificial UV light. The loss of vital algal pigments was monitored using UV–vis spectrophotometry, and cell structural changes were determined by microscopic observation. Cladophora, in the presence of TiO2-covered glass beads, experienced a loss of chloroplast pigments after 2 h of UV lamp light irradiation. In a separate experiment, sunlight exposure over 4 days (∼24 h) resulted in the complete oxidative degradation of the green chloroplast pigments, verified by the UV spectra of the algal extracts. These results suggest that TiO2, mobilized on sunlit silicates may be useful in controlling growth and survival of this alga in the Great Lakes, thus mitigating many of the economic, aesthetic ecological impacts of this invasive alga.

  4. Elucidating the Diversity of Aquatic Microdochium and Trichoderma Species and Their Activity against the Fish Pathogen Saprolegnia diclina.

    Science.gov (United States)

    Liu, Yiying; Zachow, Christin; Raaijmakers, Jos M; de Bruijn, Irene

    2016-01-21

    Animals and plants are increasingly threatened by emerging fungal and oomycete diseases. Amongst oomycetes, Saprolegnia species cause population declines in aquatic animals, especially fish and amphibians, resulting in significant perturbation in biodiversity, ecological balance and food security. Due to the prohibition of several chemical control agents, novel sustainable measures are required to control Saprolegnia infections in aquaculture. Previously, fungal community analysis by terminal restriction fragment length polymorphism (T-RFLP) revealed that the Ascomycota, specifically the genus Microdochium, was an abundant fungal phylum associated with salmon eggs from a commercial fish farm. Here, phylogenetic analyses showed that most fungal isolates obtained from salmon eggs were closely related to Microdochium lycopodinum/Microdochium phragmitis and Trichoderma viride species. Phylogenetic and quantitative PCR analyses showed both a quantitative and qualitative difference in Trichoderma population between diseased and healthy salmon eggs, which was not the case for the Microdochium population. In vitro antagonistic activity of the fungi against Saprolegnia diclina was isolate-dependent; for most Trichoderma isolates, the typical mycoparasitic coiling around and/or formation of papilla-like structures on S. diclina hyphae were observed. These results suggest that among the fungal community associated with salmon eggs, Trichoderma species may play a role in Saprolegnia suppression in aquaculture.

  5. Usefulness of bioclimatic models for studying climate change and invasive species.

    Science.gov (United States)

    Jeschke, Jonathan M; Strayer, David L

    2008-01-01

    Bioclimatic models (also known as envelope models or, more broadly, ecological niche models or species distribution models) are used to predict geographic ranges of organisms as a function of climate. They are widely used to forecast range shifts of organisms due to climate change, predict the eventual ranges of invasive species, infer paleoclimate from data on species occurrences, and so forth. Several statistical techniques (including general linear models, general additive models, climate envelope models, classification and regression trees, and genetic algorithms) have been used in bioclimatic modeling. Recently developed techniques tend to perform better than older techniques, although it is unlikely that any single statistical approach will be optimal for all applications and species. Proponents of bioclimatic models have stressed their apparent predictive power, whereas opponents have identified the following unreasonable model assumptions: biotic interactions are unimportant in determining geographic ranges or are constant over space and time; the genetic and phenotypic composition of species is constant over space and time; and species are unlimited in their dispersal. In spite of these problematic assumptions, bioclimatic models often successfully fit present-day ranges of species. Their ability to forecast the effects of climate change or the spread of invaders has rarely been tested adequately, however, and we urge researchers to tie the evaluation of bioclimatic models more closely to their intended uses.

  6. Experimental study to control the upstream migration of invasive alien fish species by submerged weir

    Science.gov (United States)

    Sakuma, Masami; Kunimatsu, Fumihiro; Tsuchiya, Taku; Kawamura, Makiko; Fujita, Hiroshi

    Largemouth bass and Bluegill, major invasive alien fish species in Japan, have been extending their habitat ranges over not only Lake Biwa and the lagoons but also surrounding waters connected to them through small rivers and canals. Their increasing number is bringing about the reduction in the number of native fish species. To prevent the spread of these alien species through small rivers and canals during breeding season of the native fish (crucian carp), this study experimentally examined the effect of a submerged weir on controlling upstream migration of the alien species and the native fish. As a result of the experiment, the ratio of the alien species migrating upstream decreased as the weir height rose, whereas the ratio did not show the same trend in the case of the native fish. The ratio of the alien species also decreased as the overflow velocity over the weir rose. On the other hand, the ratio of the native fish increased as the overflow velocity rose up to 1.0m/s and decreased thereafter. These results suggest that the submerged weir may control upstream migration of the alien species to surrounding waters through small rivers and canals without interfering with the reproductive migration of the native fish.

  7. Socioeconomic and livelihood impact of invasive species on marginal homesteads: the case of aceria guerreronis on coconut palms in India

    OpenAIRE

    Aravindakshan, Sreejith

    2011-01-01

    Alien invasive species are non-native organisms that occur outside their natural adapted habitat and dispersal potential. They are seen as a threat not only to biodiversity and ecosystems, but also to socioeconomic development, livelihood and human well-being. In India, the bioinvasion of coconut palms by an alien invasive mite species Aceria guerreronis, popularly known as ‘Coconut mite’ accounting for enormous economic loss was first noticed just before the start of the new m...

  8. Potential of "lure and kill" in long-term pest management and eradication of invasive species.

    Science.gov (United States)

    El-Sayed, A M; Suckling, D M; Byers, J A; Jang, E B; Wearing, C H

    2009-06-01

    "Lure and kill" technology has been used for several decades in pest management and eradication of invasive species. In lure and kill, the insect pest attracted by a semiochemical lure is not "entrapped" at the source of the attractant as in mass trapping, but instead the insect is subjected to a killing agent, which eliminates affected individuals from the population after a short period. In past decades, a growing scientific literature has been published on this concept. This article provides the first review on the potential of lure and kill in long-term pest management and eradication of invasive species. We present a summary of lure and kill, either when used as a stand-alone control method or in combination with other methods. We discuss its efficacy in comparison with other control methods. Several case studies in which lure and kill has been used with the aims of long-term pest management (e.g., pink bollworm, Egyptian cotton leafworm, codling moth, apple maggot, biting flies, and bark beetles) or the eradication of invasive species (e.g., tephritid fruit flies and boll weevils) are provided. Subsequently, we identify essential knowledge required for successful lure and kill programs that include lure competitiveness with natural odor source; lure density; lure formulation and release rate; pest population density and risk of immigration; and biology and ecology of the target species. The risks associated with lure and kill, especially when used in the eradication programs, are highlighted. We comment on the cost-effectiveness of this technology and its strengths and weaknesses, and list key reasons for success and failure. We conclude that lure and kill can be highly effective in controlling small, low-density, isolated populations, and thus it has the potential to add value to long-term pest management. In the eradication of invasive species, lure and kill offers a major advantage in effectiveness by its being inverse density dependent and it provides

  9. Anti-biogram and resistogram profiling of Aeromonas species isolated from Malaysian aquatic sources

    OpenAIRE

    Olumide Adedokun Odeyemi; Asmat Ahmad

    2013-01-01

    Objective: To investigate antibiotics and heavy metals resistance profile of Aeromonas species isolated from Kuala Gula and Kuala Sepetang, Perak. Methods: Isolated Aeromonas species were subjected to 12 antibiotics: penicillin G 10 units, tetracycline 30 µg, novobiocin 5 µg, nitrofurantoin 100 µg, ampicillin 10 µg, chloramphenicol 10 µg, fluconazole 25 µg, gentamicin 10 µg, streptomycin 10 µg and 25 µg, kanamycin 30 µg, and vancomycin 30 µg and 5 heavy metals: MnSO4.H2O, Cr(NO...

  10. Citizen science contributes to our knowledge of invasive plant species distributions

    Science.gov (United States)

    Crall, Alycia W.; Jarnevich, Catherine S.; Young, Nicholas E.; Panke, Brendon; Renz, Mark; Stohlgren, Thomas

    2015-01-01

    Citizen science is commonly cited as an effective approach to expand the scale of invasive species data collection and monitoring. However, researchers often hesitate to use these data due to concerns over data quality. In light of recent research on the quality of data collected by volunteers, we aimed to demonstrate the extent to which citizen science data can increase sampling coverage, fill gaps in species distributions, and improve habitat suitability models compared to professionally generated data sets used in isolation. We combined data sets from professionals and volunteers for five invasive plant species (Alliaria petiolata, Berberis thunbergii, Cirsium palustre, Pastinaca sativa, Polygonum cuspidatum) in portions of Wisconsin. Volunteers sampled counties not sampled by professionals for three of the five species. Volunteers also added presence locations within counties not included in professional data sets, especially in southern portions of the state where professional monitoring activities had been minimal. Volunteers made a significant contribution to the known distribution, environmental gradients sampled, and the habitat suitability of P. cuspidatum. Models generated with professional data sets for the other four species performed reasonably well according to AUC values (>0.76). The addition of volunteer data did not greatly change model performance (AUC > 0.79) but did change the suitability surface generated by the models, making them more realistic. Our findings underscore the need to merge data from multiple sources to improve knowledge of current species distributions, and to predict their movement under present and future environmental conditions. The efficiency and success of these approaches require that monitoring efforts involve multiple stakeholders in continuous collaboration via established monitoring networks.

  11. The Invasive Species Forecasting System (ISFS): An iRODS-Based, Cloud-Enabled Decision Support System for Invasive Species Habitat Suitability Modeling

    Science.gov (United States)

    Gill, Roger; Schnase, John L.

    2012-01-01

    The Invasive Species Forecasting System (ISFS) is an online decision support system that allows users to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of interest, such as a national park, monument, forest, or refuge. Target customers for ISFS are natural resource managers and decision makers who have a need for scientifically valid, model- based predictions of the habitat suitability of plant species of management concern. In a joint project involving NASA and the Maryland Department of Natural Resources, ISFS has been used to model the potential distribution of Wavyleaf Basketgrass in Maryland's Chesapeake Bay Watershed. Maximum entropy techniques are used to generate predictive maps using predictor datasets derived from remotely sensed data and climate simulation outputs. The workflow to run a model is implemented in an iRODS microservice using a custom ISFS file driver that clips and re-projects data to geographic regions of interest, then shells out to perform MaxEnt processing on the input data. When the model completes, all output files and maps from the model run are registered in iRODS and made accessible to the user. The ISFS user interface is a web browser that uses the iRODS PHP client to interact with the ISFS/iRODS- server. ISFS is designed to reside in a VMware virtual machine running SLES 11 and iRODS 3.0. The ISFS virtual machine is hosted in a VMware vSphere private cloud infrastructure to deliver the online service.

  12. Biological control through intraguild predation: case studies in pest control, invasive species and range expansion.

    Science.gov (United States)

    Bampfylde, C J; Lewis, M A

    2007-04-01

    Intraguild predation (IGP), the interaction between species that eat each other and compete for shared resources, is ubiquitous in nature. We document its occurrence across a wide range of taxonomic groups and ecosystems with particular reference to non-indigenous species and agricultural pests. The consequences of IGP are complex and difficult to interpret. The purpose of this paper is to provide a modelling framework for the analysis of IGP in a spatial context. We start by considering a spatially homogeneous system and find the conditions for predator and prey to exclude each other, to coexist and for alternative stable states. Management alternatives for the control of invasive or pest species through IGP are presented for the spatially homogeneous system. We extend the model to include movement of predator and prey. In this spatial context, it is possible to switch between alternative stable steady states through local perturbations that give rise to travelling waves of extinction or control. The direction of the travelling wave depends on the details of the nonlinear intraguild interactions, but can be calculated explicitly. This spatial phenomenon suggests means by which invasions succeed or fail, and yields new methods for spatial biological control. Freshwater case studies are used to illustrate the outcomes.

  13. Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.).

    Science.gov (United States)

    Yang, Ruyi; Yu, Guodong; Tang, Jianjun; Chen, Xin

    2008-01-01

    It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species (Solidago canadensis L.) in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels (control, 300, and 600 mg/kg soil) were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae, Glomus versiform, Glomus diaphanum, Glomus geosporum, and Glomus etunicatum). The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants. The results showed that S. canadensis was highly dependent on mycorrhizae. The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization (root length colonized, RLC%) but did not affect spore numbers, N (including total N and 15N) and P uptake. The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments. The Pb was mostly sequestered in belowground of plant (root and rhizome). The results suggest that the high efficiency of mycorrhizae on nutrient uptake might give S. canadensis a great advantage over native species in Pb polluted soils.

  14. Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.)

    Institute of Scientific and Technical Information of China (English)

    YANG Ruyi; YU Guodong; TANG Jianjan; CHEN Xin

    2008-01-01

    It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants.A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species(Solidago canadensis L.)in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments.Three Pb levels(control,300,and 600 mg/kg soil)were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows.Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae,Glomus versiform,Glomus diaphanum,Glomus geosporum,and Glomus etunicatum).The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants.The results showed that S. canadensis was highly dependent on mvcOrrhizae.The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization(root length colonized,RLC%) but did not affect spore numbers,N(including total N and 15N) and P uptake.The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments.The Pb was mostly sequestered in belowground of plant (root and rhizome).The results suggest that the high efficiency of mycorrhizae on nutrient uptake mightgive S. canadensis a great advantage over native species in Pb polluted softs.

  15. Corruption, development and governance indicators predict invasive species risk from trade.

    Science.gov (United States)

    Brenton-Rule, Evan C; Barbieri, Rafael F; Lester, Philip J

    2016-06-15

    Invasive species have an enormous global impact, with international trade being the leading pathway for their introduction. Current multinational trade deals under negotiation will dramatically change trading partnerships and pathways. These changes have considerable potential to influence biological invasions and global biodiversity. Using a database of 47 328 interceptions spanning 10 years, we demonstrate how development and governance socio-economic indicators of trading partners can predict exotic species interceptions. For import pathways associated with vegetable material, a significantly higher risk of exotic species interceptions was associated with countries that are poorly regulated, have more forest cover and have surprisingly low corruption. Corruption and indicators such as political stability or adherence to rule of law were important in vehicle or timber import pathways. These results will be of considerable value to policy makers, primarily by shifting quarantine procedures to focus on countries of high risk based on their socio-economic status. Further, using New Zealand as an example, we demonstrate how a ninefold reduction in incursions could be achieved if socio-economic indicators were used to select trade partners. International trade deals that ignore governance and development indicators may facilitate introductions and biodiversity loss. Development and governance within countries clearly have biodiversity implications beyond borders.

  16. The corallivorous flatworm Amakusaplana acroporae: an invasive species threat to coral reefs?

    Science.gov (United States)

    Hume, Benjamin C. C.; D'Angelo, Cecilia; Cunnington, Anna; Smith, Edward G.; Wiedenmann, Jörg

    2014-03-01

    Fatal infestations of land-based Acropora cultures with so-called Acropora- eating flatworms (AEFWs) are a global phenomenon. We evaluate the hypothesis that AEFWs represent a risk to coral reefs by studying the biology and the invasive potential of an AEFW strain from the UK. Molecular analyses identified this strain as Amakusaplana acroporae, a new species described from two US aquaria and one natural location in Australia. Our molecular data together with life history strategies described here suggest that this species accounts for most reported cases of AEFW infestations. We show that local parasitic activity impairs the light-acclimation capacity of the whole host colony. A. acroporae acquires excellent camouflage by harbouring photosynthetically competent, host-derived zooxanthellae and pigments of the green-fluorescent protein family. It shows a preference for Acropora valida but accepts a broad host range. Parasite survival in isolation (5-7 d) potentially allows for an invasion when introduced as non-native species in coral reefs.

  17. Perception and Understanding of Invasive Alien Species Issues by Nature Conservation and Horticulture Professionals in Belgium

    Science.gov (United States)

    Vanderhoeven, Sonia; Piqueray, Julien; Halford, Mathieu; Nulens, Greet; Vincke, Jan; Mahy, Grégory

    2011-03-01

    We conducted a survey to determine how two professional sectors in Belgium, horticulture professionals and nature reserve managers (those directly involved in conservation), view the issues associated with invasive plant species. We developed and utilized a questionnaire that addressed the themes of awareness, concept and use of language, availability of information, impacts and, finally, control and available solutions. Using co-inertia analyses, we tested to what extent the perception of invasive alien species (IAS) was dependent upon the perception of Nature in general. Only forty-two percent of respondent horticulture professionals and eighty-two percent of nature reserve managers had a general knowledge of IAS. Many individuals in both target groups nonetheless had an accurate understanding of the scientific issues. Our results therefore suggest that the manner in which individuals within the two groups view, or perceive, the IAS issue was more the result of lack of information than simply biased perceptions of target groups. Though IAS perceptions by the two groups diverged, they were on par with how they viewed Nature in general. The descriptions of IAS by participants converged with the ideas and concepts frequently found in the scientific literature. Both managers and horticulture professionals expressed a strong willingness to participate in programs designed to prevent the spread of, and damage caused by, IAS. Despite this, the continued commercial availability of many invasive species highlighted the necessity to use both mandatory and voluntary approaches to reduce their re-introduction and spread. The results of this study provide stakeholders and conservation managers with practical information on which communication and management strategies can be based.

  18. The potential risk assessment for different arsenic species in the aquatic environment

    Institute of Scientific and Technical Information of China (English)

    Meng Du; Dongbin Wei; Zhuowei Tan; Aiwu Lin; Yuguo Du

    2015-01-01

    The different toxicity characteristics of arsenic species result in discrepant ecological risk.The predicted no-effect concentrations (PNECs) 43.65,250.18,and 2.00 × 103 μg/L were calculated for As(Ⅲ),As(Ⅴ),and dimethylarsinic acid in aqueous phase,respectively.With these PNECs,the ecological risk from arsenic species in Pearl River Delta in China and Kwabrafo stream in Ghana was evaluated.It was found that the risk from As(Ⅲ) and As(Ⅴ)in the samples from Pearl River Delta was low,while much high in Kwabrafo stream.This study implies that ecological risk of arsenic should be evaluated basing on its species.

  19. Wildfire, climate, and invasive grass interactions negatively impact an indicator species by reshaping sagebrush ecosystems

    OpenAIRE

    2016-01-01

    The Great Basin of western North America is larger than 75% of countries worldwide and is comprised mostly of a “sagebrush sea” threatened by a novel disturbance cycle of wildfire and annual grass invasion. The greater sage-grouse is a sagebrush-obligate species whose populations generally track declines in sagebrush, and is highly influential in shaping state and national land-use policy. Using three decades of sage-grouse population count, wildfire, and climate data within a modeling framew...

  20. Distribution and status of marine invasive species in and bordering the West Coast National Park

    Directory of Open Access Journals (Sweden)

    T.B. Robinson

    2004-12-01

    Full Text Available On a global scale, species are constantly being moved from their areas of origin to new locales. Such range extensions can occur naturally, but are frequently aided (intentionally or non-intentionally by humans (Mack et al. 2000. As a result, the marked world-wide increase in animal, plant, and microbial immigrations, has been found to roughly track the increase in human commerce (Mack et al. 2000. The principal vectors of human-mediated marine invasions are ballast water (Williams et al. 1988, mariculture (Minchin 1996, sediment held in ballast tanks (Carlton 1985, and ship hull fouling (Minchin 1996.

  1. Treatment of Invasive Marine Species on Board by Using Micro-gap Discharge Plasma

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A pilot-scale experiment of 20 t/h for the treatment of ship's ballast water is reexperiment, the rate of destroying bacteria, mono-algae, protozoan reached 100% within 2.67 s.The effect of hydroxyl radicals on biochemical processes was also studied. The attenuation rate of photosynthesis pigment was 100%. And the main reason for the cells' death was the strong destruction of the monose, amylose, protein, DNA and RNA in the cells. As an advanced oxidation method, the procedure can destroy invasive marine species when a ship is in the process of discharging its ballast water.

  2. Long time behavior of a PDE model for invasive species control

    KAUST Repository

    Parshad, R.D.

    2011-01-01

    The Trojan Y Chromosome strategy (TYC) is a theoretical method for eradication of invasive species. It requires constant introduction of artificial individuals into a target population, causing a shift in the sex ratio, that ultimately leads to local extinction. In this work we consider a modified version of the TYC system. We first demonstrate the existence of a unique weak solution to the system. Furthermore, we prove the existence of a compact finite dimensional global attractor for the modified system, in L 2(Ω) × L 2(Ω)× L 2(Ω).

  3. Invasive species and coal bed methane development in the Powder River Basin, Wyoming

    Science.gov (United States)

    Bergquist, E.; Evangelista, P.; Stohlgren, T.J.; Alley, N.

    2007-01-01

    One of the fastest growing areas of natural gas production is coal bed methane (CBM) due to the large monetary returns and increased demand for energy from consumers. The Powder River Basin, Wyoming is one of the most rapidly expanding areas of CBM development with projections of the establishment of up to 50,000 wells. CBM disturbances may make the native ecosystem more susceptible to invasion by non-native species, but there are few studies that have been conducted on the environmental impacts of this type of resource extraction. To evaluate the potential effects of CBM development on native plant species distribution and patterns of non-native plant invasion, 36 modified Forest Inventory and Analysis plots (each comprised of four 168-m2 subplots) were established in the Powder River Basin, Wyoming. There were 73 168-m2 subplots on control sites; 42 subplots on secondary disturbances; 14 on major surface disturbances; eight on well pads; and seven on sites downslope of CBM wells water discharge points. Native plant species cover ranged from 39.5 ?? 2.7% (mean ?? 1 SE) in the secondary disturbance subplots to 17.7 ?? 7.5% in the pad subplots. Non-native plant species cover ranged from 31.0 ?? 8.4% in the discharge areas to 14.7 ?? 8.9% in the pad subplots. The control subplots had significantly less non-native species richness than the combined disturbance types. The combined disturbance subplots had significantly greater soil salinity than the control sites. These results suggest that CBM development and associated disturbances may facilitate the establishment of non-native plants. Future research and management decisions should consider the accumulative landscape-scale effects of CBM development on preserving native plant diversity. ?? Springer Science+Business Media B.V. 2006.

  4. Invasive species and coal bed methane development in the Powder River Basin, Wyoming.

    Science.gov (United States)

    Bergquist, E; Evangelista, P; Stohlgren, T J; Alley, N

    2007-05-01

    One of the fastest growing areas of natural gas production is coal bed methane (CBM) due to the large monetary returns and increased demand for energy from consumers. The Powder River Basin, Wyoming is one of the most rapidly expanding areas of CBM development with projections of the establishment of up to 50,000 wells. CBM disturbances may make the native ecosystem more susceptible to invasion by non-native species, but there are few studies that have been conducted on the environmental impacts of this type of resource extraction. To evaluate the potential effects of CBM development on native plant species distribution and patterns of non-native plant invasion, 36 modified Forest Inventory and Analysis plots (each comprised of four 168-m2 subplots) were established in the Powder River Basin, Wyoming. There were 73 168-m2 subplots on control sites; 42 subplots on secondary disturbances; 14 on major surface disturbances; eight on well pads; and seven on sites downslope of CBM wells water discharge points. Native plant species cover ranged from 39.5 +/- 2.7% (mean +/- 1 SE) in the secondary disturbance subplots to 17.7 +/- 7.5% in the pad subplots. Non-native plant species cover ranged from 31.0 +/- 8.4% in the discharge areas to 14.7 +/- 8.9% in the pad subplots. The control subplots had significantly less non-native species richness than the combined disturbance types. The combined disturbance subplots had significantly greater soil salinity than the control sites. These results suggest that CBM development and associated disturbances may facilitate the establishment of non-native plants. Future research and management decisions should consider the accumulative landscape-scale effects of CBM development on preserving native plant diversity.

  5. The Human Release Hypothesis for biological invasions: human activity as a determinant of the abundance of invasive plant species [v1; ref status: indexed, http://f1000r.es/33c

    Directory of Open Access Journals (Sweden)

    Heike Zimmermann

    2014-05-01

    Full Text Available Research on biological invasions has increased rapidly over the past 30 years, generating numerous explanations of how species become invasive. While the mechanisms of invasive species establishment are well studied, the mechanisms driving abundance patterns (i.e. patterns of population density remain poorly understood. Invasive species typically have higher abundances in their new environments than in their native ranges, and patterns of invasive species abundance differ between invaded regions. To explain differences in invasive species abundance, we propose the Human Release Hypothesis. In parallel to the established Enemy Release Hypothesis, this hypothesis states that the abundance of invasive species may be partly explained by the level of human activity or landscape maintenance, with intermediate levels of human activity providing optimal conditions for high abundance. The Human Release Hypothesis does not negate other important drivers of species invasions, but rather should be considered as a potentially important additional or complementary mechanism. We illustrate the hypothesis via a case study on an invasive rose species, and hypothesize which locations globally may be most likely to support high abundances of invasive species. We propose that more extensive empirical work on the Human Release Hypothesis could be useful to test its general applicability.

  6. The application of the European strategy on invasive alien species: an example with introduced squirrels

    Directory of Open Access Journals (Sweden)

    Sandro Bertolino

    2005-06-01

    Full Text Available Abstract We assessed the cases of squirrel species already introduced into Italy inside the framework proposed by the European strategy on invasive alien species. We collected information on 9 introductions that originated 8 populations: 3 of grey squirrels (Sciurus carolinensis, 2 of Finlayson's squirrels (Callosciurus finlaysonii, and 3 of Siberian chip-munks (Eutamias sibiricus. Food opportunism and high reproductive rate may explain the high success rate in establishing new populations, even with a low propagule pressure. A negative impact on the red squirrel (Sciurus vulgaris and damage to forestry and manufactures have been recorded in the areas of introduction. Accordingly to the European strategy, Italy is called to build-up a rapid response system in order to avoid further releases of alien squirrels in the wild. Meanwhile these species must be considered as a priority for trade restriction. Considering the risks posed to biodiversity and human activities, Italy must adopt a precautionary principle, removing small nuclei of introduced species before they spread in large areas. Riassunto Applicazione della strategia europea sulle specie non indigene: un esempio con gli scoiattoli introdotti Come esempio di applicazione della strategia europea sulle specie invasive introdotte, abbiamo analizzato la situazione degli scoiattoli introdotti in Italia. Su 9 introduzioni registrate, in 8 casi si sono formate popolazioni naturalizzate: 3 di scoiattolo grigio (Sciurus carolinensis, 2 di scoiattolo di Finlayson (Callosciurus finlaysonii e 3 di tamia siberiano (Eutamias sibiricus. L'alto successo delle introduzioni, anche a partire da pochi animali rilasciati, è probabilmente legato all'opportunismo alimentare delle specie considerate e al loro elevato tasso riproduttivo. Al momento, nelle aree di introduzione sono segnalati fenomeni

  7. Aquatic tardigrades in the Great Smoky Mountains National Park, North Carolina and Tennessee, U.S.A., with the description of a new species of Thulinius (Tardigrada, Isohypsibiidae).

    Science.gov (United States)

    Bertolani, Roberto; Bartels, Paul J; Guidetti, Roberto; Cesari, Michele; Nelson, Diane R

    2014-02-05

    As part of the All Taxa Biodiversity Inventory (http://www.dlia.org), an extensive survey of tardigrades has been conducted in the Great Smoky Mountains National Park (GSMNP) in Tennessee and North Carolina, U.S.A., by Bartels and Nelson. Freshwater tardigrades include three species in the aquatic genus Thulinius (Eutardigrada, Isohypsibiidae). A new species, Thulinius romanoi, described from stream sediment, is distinguished from all other congeners by having a sculptured cuticle. In addition, the presence of Thulinius augusti (Murray, 1907) was verified by combined morphological and molecular analysis, and nine specimens of a third species, Thulinius cf. saltursus, were also found. Thulinius augusti is a new record for the United States. Thulinius saltursus (Schuster, Toftner & Grigarick, 1978) was previously recorded in California and Ohio, but our specimens vary slightly in morphology. The list of tardigrades from streams in the GSMNP was updated to a total of 44 species, 22 of which were predominantly or exclusively aquatic.

  8. Foliar Epidermal Traits of Invasive and Non-Invasive Species of Dracaena Vand. ex L. (Dracaenaceae in Obafemi Awolowo University Campus, Ile-Ife, Nigeria

    Directory of Open Access Journals (Sweden)

    Abayomi Ezekiel FOLORUNSO

    2016-06-01

    Full Text Available A comparative foliar anatomical study of the invasive and non-invasive species of Dracaena in Obafemi Awolowo University Campus in Nigeria was carried out. A specific aim of the study was to determine the foliar and morphological traits in Dracaena mannii, which may be responsible for its invasive habit. The foliar anatomical traits were also used to describe the two studied Dracaena species. Fresh and matured leaves of D. mannii and D. arborea were collected and authenticated at the Herbarium of Obafemi Awolowo University (IFE. Quantitative and qualitative data were recorded for morphological traits, whereas scraping techniques were used to obtain the epidermal peels and photomicrographs of slides were taken for observing the anatomical traits. The presence of club-like glandular unicellular trichomes and papillose, high stomata index and frequency of epidermal cells per unit area strengthen the invasive habit of Dracaena mannii. The thin walls of the epidermal cells increase the intercellular flow of assimilates within D. mannii, which is also a notable invasive character.

  9. Trait differences between naturalized and invasive plant species independent of residence time and phylogeny

    Science.gov (United States)

    Gallagher, R V; Randall, R P; Leishman, M R

    2015-01-01

    The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species’ native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the

  10. Mind the gap – context dependency in invasive species impacts: a case study of the ascidian Ciona robusta

    Directory of Open Access Journals (Sweden)

    Tamara B. Robinson

    2017-01-01

    Full Text Available In the face of increasing invasions and limited resources, appropriate management of invasive species requires prioritisation of species for management action. This process often relies on knowledge of species specific impacts. However, as studies explicitly measuring impact of marine alien species are rare, prioritisation of management actions is often based on studies from outside the geographic area of interest. Further, few impact studies account for context dependency (e.g. seasonal variability or distinct environmental regimes, raising the question of how transferrable knowledge about the impact of a species is between invaded ranges. This study addressed this question by using the widespread invasive solitary ascidian Ciona robusta as a case study for assessing impacts across two invaded regions: South Africa and California, USA. We replicated a previously conducted experiment from California that showed that C. robusta depresses local species richness in San Francisco Bay. Our South African experiment showed no effect of C. robusta on species richness, the Shannon-Weiner diversity index or community composition, despite experiments being carried out over two years and at two depths. While these results may reflect strong density dependency in the impact of C. robusta, they serve to highlight context dependency in invasive species impacts. This suggests that until studies of impact in marine systems become common place, context dependency should be explicitly addressed as a source of uncertainty during the prioritisation of species for management action.

  11. RNA Editing in Chloroplasts of Spirodela polyrhiza, an Aquatic Monocotelydonous Species

    OpenAIRE

    2015-01-01

    RNA editing is the post-transcriptional conversion from C to U before translation, providing a unique feature in the regulation of gene expression. Here, we used a robust and efficient method based on RNA-seq from non-ribosomal total RNA to simultaneously measure chloroplast-gene expression and RNA editing efficiency in the Greater Duckweed, Spirodela polyrhiza, a species that provides a new reference for the phylogenetic studies of monocotyledonous plants. We identified 66 editing sites at t...

  12. Differential endozoochory of aquatic invertebrates by two duck species in shallow lakes

    Science.gov (United States)

    Valls, Luis; Castillo-Escrivà, Andreu; Barrera, Luis; Gómez, Eulalia; Gil-Delgado, José Antonio; Mesquita-Joanes, Francesc; Armengol, Xavier

    2017-04-01

    Animal vectors are essential for the movement of invertebrate resting eggs between water bodies. However, differences in habitat preferences and feeding behaviour between bird species may result in variations in the dispersal of invertebrates via these birds, even if the different bird species live in the same lake. To test such effects, faecal samples from Anas platyrhynchos (collected in autumn and spring) and Tadorna tadorna (collected in spring) were cultured in water at 20° C and 12 L: 12 D conditions in order to quantify the resting eggs which could be internally transported by these birds. One half of each faecal sample was initially cultured at a conductivity of 0.6 mS cm-1 and the other half at 6 mS cm-1. 1054 invertebrates hatched from a total of 60 faecal samples, including cladocerans, copepods, ostracods, rotifers and ciliates, with a wide variability among faeces. Autumn yielded a low proportion of samples with hatchlings (12.5%) compared to spring (90%). Significant differences were observed between birds, but not between conductivity treatments. Thus, our results imply different hatching dynamics affected by disperser and season, but most species transported as resting eggs by birds seem to have a wide tolerance to hatch under variable salinity conditions. These differences may largery influence the metacommunity dynamics of lake networks, and could be a key factor to consider in wetland conservation planning.

  13. Aeromonas rivipollensis sp. nov., a novel species isolated from aquatic samples.

    Science.gov (United States)

    Marti, Elisabet; Balcázar, José Luis

    2015-12-01

    Two gram-negative, facultatively anaerobic, motile and rod-shaped bacteria, strains P2G1(T) and P1A11, were isolated from the Ter River in Ripoll, Spain. Phylogenetic analysis based on 16S rRNA gene sequences showed that both strains are closely related to each other and that their closest relatives were Aeromonas media ATCC 33907(T) (99.4%) and Aeromonas hydrophila ATCC 7966(T) (99.3%). Multilocus sequence analysis (MLSA) based on the partial sequences of gyrA, gyrB, rpoD, recA, and dnaJ genes suggested that these two strains represent a novel species that clustered with A. media ATCC 33907(T). This was further supported by DNA-DNA hybridization analysis between P2G1(T) and A. media LMG 9073(T). Phenotypic features also allowed their differentiation from closely related species. These two strains should, therefore, be considered to represent a novel species within the genus Aeromonas, for which the name Aeromonas rivipollensis sp. nov. is proposed.

  14. [Distribution of polybrominated diphenyl ethers in aquatic species from the Pearl River Estuary].

    Science.gov (United States)

    Xiang, Cai-hong; Luo, Xiao-jun; Yu, Mei; Meng, Xiang-zhou; Mai, Bi-xian; Zeng, Eddy

    2006-09-01

    Polybrominated diphenyl ethers (PBDEs) were detected in biota samples collected from the Pearl River Estuary. The concentrations of sigma10 PBDEs (BDE28, 47, 66, 100, 99, 85, 154, 153, 138, 183) in fish species (including Platycephalus indicus, Pseudosiaena crocea , Pampus argenteus, Cynoglossus robustus, and Harpodon nehereus), shrimps (including Metapenaeus ensis and Metapenaeus affinis) and Squilla oratoria were from 37.8 ng x g(-1) to 407.1 ng x g(-1) (normalized to lipid), from 49.0 ng x g(-1) to 239.1 ng x g(-1) and from 142 ng x g(-1) to 444.5 ng x g(-1), respectively. BDE47 was the dominant congener in all biota samples, with a contribution to sigma10 PBDEs ranging from 53.7% to 66.9%. Differences in concentrations of PBDEs and PBDE patterns in different species may be related to the different feeding habit, living environment and uptaking or elimination rate. High ratios of concentrations of PBDEs in liver /muscle in fish species indicated that PBDEs tended to accumulate more in liver than in muscle.

  15. Reproductive characteristics of the invasive species Solanum rostratum in different habitats of Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Juan Qiu

    2013-09-01

    Full Text Available The invasiveness of alien plants is closely related to their reproductive characteristics. A comparison of reproductive characteristics of an alien species in different habitats will help to reveal its optimum habitat for invasion and the mechanism of invasion. Furthermore, it will provide a theoretical foundation for planning a reasonable management strategy. Solanum rostratum is a summer annual weed native to the neotropics and the southwestern USA that produces offspring only by sexual reproduction. This species has become established in seven provinces/cities of China, including Xinjiang. We compared reproductive characteristics of S. rostratum in oasis, desert grassland and gravel desert habitats in Xinjiang and determined the optimum habitat for its invasion. The results were as follows. (1 Single-flower duration of S. rostratum was between 27 and 47 hours. Daily flowering time and single-flower duration were similar among the three habitats. However, number of flowers per individual differed among habitats (P<0.01=: oasis > desert grassland > gravel desert. (2 Halictus quadricinctus, Halictus sp. and Xylocopa latipes were the pollinators of S. rostratum, and all of them buzz-pollinated flowers. However, X. latipes visited flowers only occasionally. (3 Total visiting frequency of pollinators differed among habitats (P desert grassland > gravel desert. Halictus quadricinctus preferred habitats with relatively low temperatures and high humidity, while another species of Halictus preferred relatively high temperatures and low humidity. Thus, the daily time of the peak of visiting frequency of H. quadricinctus was earlier than that of Halictus sp. (4 Order of number of fruits per individual, seed number per fruit and per individual and mass of 1,000 seeds was oasis > desert grassland > gravel desert. Fruit number per individual was highly significantly positively correlated with both number of flowers per individual and total visiting

  16. Hyperspectral Mapping of the Invasive Species Pepperweed and the Development of a Habitat Suitability Model

    Science.gov (United States)

    Nguyen, Andrew; Gole, Alexander; Randall, Jarom; Dlott, Glade; Zhang, Sylvia; Alfaro, Brian; Schmidt, Cindy; Skiles, J. W.

    2011-01-01

    Mapping and predicting the spatial distribution of invasive plant species is central to habitat management, however difficult to implement at landscape and regional scales. Remote sensing techniques can reduce the impact field campaigns have on these ecologically sensitive areas and can provide a regional and multi-temporal view of invasive species spread. Invasive perennial pepperweed (Lepidium latifolium) is now widespread in fragmented estuaries of the South San Francisco Bay, and is shown to degrade native vegetation in estuaries and adjacent habitats, thereby reducing forage and shelter for wildlife. The purpose of this study is to map the present distribution of pepperweed in estuarine areas of the South San Francisco Bay Salt Pond Restoration Project (Alviso, CA), and create a habitat suitability model to predict future spread. Pepperweed reflectance data were collected in-situ with a GER 1500 spectroradiometer along with 88 corresponding pepperweed presence and absence points used for building the statistical models. The spectral angle mapper (SAM) classification algorithm was used to distinguish the reflectance spectrum of pepperweed and map its distribution using an image from EO-1 Hyperion. To map pepperweed, we performed a supervised classification on an ASTER image with a resulting classification accuracy of 71.8%. We generated a weighted overlay analysis model within a geographic information system (GIS) framework to predict areas in the study site most susceptible to pepperweed colonization. Variables for the model included propensity for disturbance, status of pond restoration, proximity to water channels, and terrain curvature. A Generalized Additive Model (GAM) was also used to generate a probability map and investigate the statistical probability that each variable contributed to predict pepperweed spread. Results from the GAM revealed distance to channels, distance to ponds and curvature were statistically significant (p habitats.

  17. Hyperspectral Mapping of the Invasive Species Pepperweed and the Development of a Habitat Suitability Model

    Science.gov (United States)

    Nguyen, A.; Gole, A.; Randall, J.; Dlott, G. A.; Zhang, S.; Alfaro, B.; Schmidt, C.; Skiles, J. W.

    2011-12-01

    Mapping and predicting the spatial distribution of invasive plant species is central to habitat management, however difficult to implement at landscape and regional scales. Remote sensing techniques can reduce the cost of field campaigns and can provide a regional and multi-temporal view of invasive species spread. Invasive perennial pepperweed (Lepidium latifolium) is now widespread in fragmented estuaries of the South San Francisco Bay, and is shown to degrade native vegetation in estuaries and adjacent habitats, thereby reducing forage and shelter for wildlife. The purpose of this study is to map the current distribution of pepperweed in estuarine areas of the South San Francisco Bay Salt Pond Restoration Project, and create a habitat suitability model to predict future spread. Pepperweed reflectance data were collected in-situ with a GER 1500 spectroradiometer along with 88 corresponding pepperweed presence and absence points used for building the statistical models. The spectral angle mapper (SAM) classification algorithm was used to distinguish the reflectance spectrum of pepperweed and map its distribution using an EO-1 Hyperion satellite image. To map pepperweed, a supervised classification was performed on an ASTER image with a resulting classification accuracy of 71.8%. We generated a weighted overlay analysis model within a geographic information system (GIS) framework to predict areas in the study site most susceptible to pepperweed colonization. Variables for the model included propensity for disturbance, status of pond restoration, proximity to water channels, and terrain curvature. A Generalized Additive Model (GAM) was also used to generate a probability map and investigate the statistical probability that each variable contributed to predict pepperweed spread. Results from the GAM revealed distance to channels, distance to ponds and curvature were statistically significant (p < 0.01) in determining the locations of suitable pepperweed habitats.

  18. Ensemble forecasting of potential habitat for three invasive fishes

    Science.gov (United States)

    Poulos, Helen M.; Chernoff, Barry; Fuller, Pam L.; Butman, David

    2012-01-01

    Aquatic invasive species pose major ecological and economic threats to aquatic ecosystems worldwide via displacement, predation, or hybridization with native species and the alteration of aquatic habitats and hydrologic cycles. Modeling the habitat suitability of alien aquatic species through spatially explicit mapping is an increasingly important risk assessment tool. Habitat modeling also facilitates identification of key environmental variables influencing invasive species distributions. We compared four modeling methods to predict the potential continental United States distributions of northern snakehead Channa argus (Cantor, 1842), round goby Neogobius melanostomus (Pallas, 1814), and silver carp Hypophthalmichthys molitrix (Valenciennes, 1844) using maximum entropy (Maxent), the genetic algorithm for rule set production (GARP), DOMAIN, and support vector machines (SVM). We used inventory records from the USGS Nonindigenous Aquatic Species Database and a geographic information system of 20 climatic and environmental variables to generate individual and ensemble distribution maps for each species. The ensemble maps from our study performed as well as or better than all of the individual models except Maxent. The ensemble and Maxent models produced significantly higher accuracy individual maps than GARP, one-class SVMs, or DOMAIN. The key environmental predictor variables in the individual models were consistent with the tolerances of each species. Results from this study provide insights into which locations and environmental conditions may promote the future spread of invasive fish in the US.

  19. The potential for biodiversity offsetting to fund effective invasive species control.

    Science.gov (United States)

    Norton, David A; Warburton, Bruce

    2015-02-01

    Compensating for biodiversity losses in 1 location by conserving or restoring biodiversity elsewhere (i.e., biodiversity offsetting) is being used increasingly to compensate for biodiversity losses resulting from development. We considered whether a form of biodiversity offsetting, enhancement offsetting (i.e., enhancing the quality of degraded natural habitats through intensive ecological management), can realistically secure additional funding to control biological invaders at a scale and duration that results in enhanced biodiversity outcomes. We suggest that biodiversity offsetting has the potential to enhance biodiversity values through funding of invasive species control, but it needs to meet 7 key conditions: be technically possible to reduce invasive species to levels that enhance native biodiversity; be affordable; be sufficiently large to compensate for the impact; be adaptable to accommodate new strategic and tactical developments while not compromising biodiversity outcomes; acknowledge uncertainties associated with managing pests; be based on an explicit risk assessment that identifies the cost of not achieving target outcomes; and include financial mechanisms to provide for in-perpetuity funding. The challenge then for conservation practitioners, advocates, and policy makers is to develop frameworks that allow for durable and effective partnerships with developers to realize the full potential of enhancement offsets, which will require a shift away from traditional preservation-focused approaches to biodiversity management.

  20. The Shell of the Invasive Bivalve Species Dreissena polymorpha: Biochemical, Elemental and Textural Investigations

    Science.gov (United States)

    Broussard, Cédric; Catherinet, Bastien; Plasseraud, Laurent; Alcaraz, Gérard; Bundeleva, Irina; Marin, Frédéric

    2016-01-01

    The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an external thin layer, the characteristics of which differ from what was described in earlier publication. We show that the shell selectively concentrates some heavy metals, in particular uranium, which predisposes D. polymorpha to local bioremediation of this pollutant. We establish the biochemical signature of the shell matrix, demonstrating that it interacts with the in vitro precipitation of calcium carbonate and inhibits calcium carbonate crystal formation, but these two properties are not strongly expressed. This matrix, although overall weakly glycosylated, contains a set of putatively calcium-binding proteins and a set of acidic sulphated proteins. 2D-gels reveal more than fifty proteins, twenty of which we identify by MS-MS analysis. We tentatively link the shell protein profile of D. polymorpha and the peculiar recent evolution of this invasive species of Ponto-Caspian origin, which has spread all across Europe in the last three centuries. PMID:27213644

  1. Modelling the impacts of an invasive species across landscapes: a step-wise approach.

    Science.gov (United States)

    Ward, Darren; Morgan, Fraser

    2014-01-01

    We estimate the extent of ecological impacts of the invasive Asian paper wasp across different landscapes in New Zealand. We used: (i) a baseline distribution layer (modelled via MaxEnt); (ii) Asian paper wasp nest density (from >460 field plots, related to their preferences for specific land cover categories); and (iii) and their foraging intensity (rates of foraging success, and the time available to forage on a seasonal basis). Using geographic information systems this information is combined and modelled across different landscapes in New Zealand in a step-wise selection process. The highest densities of Asian paper wasps were in herbaceous saline vegetation, followed closely by built-up areas, and then scrub and shrubland. Nest densities of 34 per ha, and occupancy rates of 0.27 were recorded for herbaceous saline vegetation habitats. However, the extent of impacts of the Asian paper wasp remains relatively restricted because of narrow climate tolerances and spatial restriction of preferred habitats. A step-wise process based on geographic information systems and species distribution models, in combination with factors such as distribution, density, and predation, create a useful tool that allows the extent of impacts of invasive species to be assessed across large spatial scales. These models will be useful for conservation managers as they provide easy visual interpretation of results, and can help prioritise where direct conservation action or control of the invader are required.

  2. The Shell of the Invasive Bivalve Species Dreissena polymorpha: Biochemical, Elemental and Textural Investigations.

    Directory of Open Access Journals (Sweden)

    Françoise Immel

    Full Text Available The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an external thin layer, the characteristics of which differ from what was described in earlier publication. We show that the shell selectively concentrates some heavy metals, in particular uranium, which predisposes D. polymorpha to local bioremediation of this pollutant. We establish the biochemical signature of the shell matrix, demonstrating that it interacts with the in vitro precipitation of calcium carbonate and inhibits calcium carbonate crystal formation, but these two properties are not strongly expressed. This matrix, although overall weakly glycosylated, contains a set of putatively calcium-binding proteins and a set of acidic sulphated proteins. 2D-gels reveal more than fifty proteins, twenty of which we identify by MS-MS analysis. We tentatively link the shell protein profile of D. polymorpha and the peculiar recent evolution of this invasive species of Ponto-Caspian origin, which has spread all across Europe in the last three centuries.

  3. Stress relief may promote the evolution of greater phenotypic plasticity in exotic invasive species: a hypothesis.

    Science.gov (United States)

    Huang, Qiao Q; Pan, Xiao Y; Fan, Zhi W; Peng, Shao L

    2015-03-01

    Invasion ecologists have often found that exotic invaders evolve to be more plastic than conspecific populations from their native range. However, an open question is why some exotic invaders can even evolve to be more plastic given that there may be costs to being plastic. Investigation into the benefits and costs of plasticity suggests that stress may constrain the expression of plasticity (thereby reducing the benefits of plasticity) and exacerbate the costs of plasticity (although this possibility might not be generally applicable). Therefore, evolution of adaptive plasticity is more likely to be constrained in stressful environments. Upon introduction to a new range, exotic species may experience more favorable growth conditions (e.g., because of release from natural enemies). Therefore, we hypothesize that any factors mitigating stress in the introduced range may promote exotic invaders to evolve increased adaptive plasticity by reducing the costs and increasing the benefits of plasticity. Empirical evidence is largely consistent with this hypothesis. This hypothesis contributes to our understanding of why invasive species are often found to be more competitive in a subset of environments. Tests of this hypothesis may not only help us understand what caused increased plasticity in some exotic invaders, but could also tell us if costs (unless very small) are more likely to inhibit the evolution of adaptive plasticity in stressful environments in general.

  4. Modelling the impacts of an invasive species across landscapes: a step-wise approach

    Directory of Open Access Journals (Sweden)

    Darren Ward

    2014-06-01

    Full Text Available We estimate the extent of ecological impacts of the invasive Asian paper wasp across different landscapes in New Zealand. We used: (i a baseline distribution layer (modelled via MaxEnt; (ii Asian paper wasp nest density (from >460 field plots, related to their preferences for specific land cover categories; and (iii and their foraging intensity (rates of foraging success, and the time available to forage on a seasonal basis. Using geographic information systems this information is combined and modelled across different landscapes in New Zealand in a step-wise selection process. The highest densities of Asian paper wasps were in herbaceous saline vegetation, followed closely by built-up areas, and then scrub and shrubland. Nest densities of 34 per ha, and occupancy rates of 0.27 were recorded for herbaceous saline vegetation habitats. However, the extent of impacts of the Asian paper wasp remains relatively restricted because of narrow climate tolerances and spatial restriction of preferred habitats. A step-wise process based on geographic information systems and species distribution models, in combination with factors such as distribution, density, and predation, create a useful tool that allows the extent of impacts of invasive species to be assessed across large spatial scales. These models will be useful for conservation managers as they provide easy visual interpretation of results, and can help prioritise where direct conservation action or control of the invader are required.

  5. First record of Ceratium furcoides (Dinophyta, an invasive species, in a temporary high-altitude lake in the Iron Quadrangle (MG, Southeast Brazil

    Directory of Open Access Journals (Sweden)

    RA. Moreira

    Full Text Available Dinoflagellates of the genus Ceratium are generally marine organisms, but rare occurrences in freshwater have been observed in Brazil. In this paper we are recording for the first time the presence of Ceratium furcoides, an invasive species, in a shallow, natural intermittent pool formed at a high-altitude at the southern end of the Iron Quadrangle, an iron-mining district of Minas Gerais State (Southeast Brazil. Samples were collected in October and November of 2010 (rainy period. The population density of this organism observed in Lagoa Seca (“Dry Pool” was very low, at most 4 ind L–1. Mountain lakes are extremely vulnerable to atmospheric deposition of organisms, making them valuable witnesses both of the many forms of impact arising from human activities and of the extended global connections that facilitate the dispersion and introduction of new species over great distances. Studies on the population dynamics of C. furcoides in natural tropical systems are still rare and very recent to the brazilian scenario and hence the monitoring of its dynamics and the potential impact on aquatic communities of its becoming established are essential to an understanding of the process of bioinvasion by this species.

  6. Estimating suitable environments for invasive plant species across large landscapes: a remote sensing strategy using Landsat 7 ETM+

    Science.gov (United States)

    Young, Kendal E.; Abbott, Laurie B.; Caldwell, Colleen A.; Schrader, T. Scott

    2013-01-01

    The key to reducing ecological and economic damage caused by invasive plant species is to locate and eradicate new invasions before they threaten native biodiversity and ecological processes. We used Landsat Enhanced Thematic Mapper Plus imagery to estimate suitable environments for four invasive plants in Big Bend National Park, southwest Texas, using a presence-only modeling approach. Giant reed (Arundo donax), Lehmann lovegrass (Eragrostis lehmanniana), horehound (Marrubium vulgare) and buffelgrass (Pennisteum ciliare) were selected for remote sensing spatial analyses. Multiple dates/seasons of imagery were used to account for habitat conditions within the study area and to capture phenological differences among targeted species and the surrounding landscape. Individual species models had high (0.91 to 0.99) discriminative ability to differentiate invasive plant suitable environments from random background locations. Average test area under the receiver operating characteristic curve (AUC) ranged from 0.91 to 0.99, indicating that plant predictive models exhibited high discriminative ability to differentiate suitable environments for invasive plant species from random locations. Omission rates ranged from <1.0 to 18%. We demonstrated that useful models estimating suitable environments for invasive plants may be created with <50 occurrence locations and that reliable modeling using presence-only datasets can be powerful tools for land managers.

  7. Invasion Age and Invader Removal Alter Species Cover and Composition at the Suisun Tidal Marsh, California, USA

    Directory of Open Access Journals (Sweden)

    Sarah Estrella

    2011-05-01

    Full Text Available Wetland ecosystems are vulnerable to plant species invasions, which can greatly alter species composition and ecosystem functioning. The response of these communities to restoration can vary following invader removal, but few studies have evaluated how recent and long-term invasions can affect the plant community’s restoration potential. Perennial pepperweed (Lepidium latifolium has invaded thousands of hectares of marshland in the San Francisco Estuary, California, United States of America, while the effects of invasion and removal of this weed remain poorly studied. In this study, perennial pepperweed was removed along a gradient of invasion age in brackish tidal marshes of Suisun Marsh, within the Estuary. In removal plots, resident plant cover significantly increased during the 2-year study period, particularly in the densest and oldest parts of the perennial pepperweed colonies, while species richness did not change significantly. In bare areas created by removal of perennial pepperweed, recolonization was dominated by three-square bulrush (Schoenoplectus americanus. Ultimately, removal of invasive perennial pepperweed led to reinvasion of the resident plant community within two years. This study illustrates that it is important to consider invasion age, along with exotic species removal, when developing a restoration strategy in wetland ecosystems.

  8. Bioaccumulation dynamics and exposure routes of Cd and Cu among species of aquatic mayflies

    Science.gov (United States)

    Cain, D.; Croteau, M.-N.; Luoma, S.

    2011-01-01

    Consumption of periphyton is a potentially important route of metal exposure to benthic invertebrate grazers. The present study examined the bioaccumulation kinetics of dissolved and dietary Cd and Cu in five species of mayflies (class Insecta). Artificial stream water and benthic diatoms were separately labeled with enriched stable metal isotopes to determine physiological rate constants used by a biokinetic bioaccumulation model. The model was employed to simulate the effects of metal partitioning between water and food, expressed as the bioconcentration factor (BCF), as well as ingestion rate (IR) and metal assimilation efficiency of food (AE), on the relative importance of water and food to metal bioaccumulation. For all test species, the contribution of dietary uptake of Cd and Cu increased with BCF. For a given BCF, the contribution of food to the body burden increased with kuf, the metal uptake rate constant from food that combined variation in IR and AE. To explore the relative importance of water and diet exposure routes under field conditions, we used estimated site-specific aqueous free-ion concentrations to model Cd and Cu accumulation from aqueous exposure, exclusively. The predicted concentrations accounted for less than 5% of the observed concentrations, implying that most bioaccumulated metal was acquired from food. At least for the taxa considered in this study, we conclude that consumption of metal-contaminated periphyton can result in elevated metal body burdens and potentially increase the risk of metal toxicity. ?? 2011 SETAC.

  9. Effectiveness of Selected Native Plants as Competitors with Non-indigenous and Invasive Knapweed and Thistle Species

    Science.gov (United States)

    2011-09-01

    and phenology of the two grass species. In controlled greenhouse settings and field plantings, this work examined the growth, seed production, and...Maternal grass individuals were collected to examine the influence of the invasions on population genetics and phenology of the two species. In...12 2.2 Testing genetic variation of invaded and non-invaded Sporobolus airoides

  10. Antioxidative Responses and Metal Accumulation in Invasive Plant Species Growing on Mine Tailings in Zanjan, Iran

    Institute of Scientific and Technical Information of China (English)

    M. M. A. BOO JAR; Z. TAVAKKOLI

    2011-01-01

    Tailings of a Pb and Zn mine as a metal-contaminated area (Zone 1) with two pioneer plant species,Peganum harmala and Zygophyllum fabago,were investigated and compared with a non-contaminated area (Zone 2) in the vicinity.Total concentrations of Pb,Zn,and Cu in the soil of Zone 1 were 1 416,2217,and 426 mg kg-1,respectively,and all exceeded their ranges in the normal soils.The soil pH was in the neutral range and most of the physical and chemical characteristics of the soils from both zones were almost similar.The species Z.fabago accumulated higher Cu and Zn in its aerial part and roots than the normal plants.On the other.hand,their concentrations did not reach the criteria that the species could be considered as a metal hyperaccumulator.The species P.harmala did not absorb metals in its roots; accordingly,the accumulation factor values of these metals were lower than 1.The contents of chlorophyll,biomass,malondialdehyde,and dityrosine in these two species did not vary significantly between the two zones studied.In Zone 1,leaf vacuoles of Z.fabago stored 35.6% and 43.2% of the total leaf Cu and Zn,respectively.However,in this species,the levels of phytochelatins (PCs) and glutathione (GSH) and antioxidant enzyme activities were significantly higher in Zone 1 than in Zone 2.In conclusion,metal exclusion in P.harmala and metal accumulation in Z.fabago were the basic strategies in the two studied pioneer species growing on the metal-contaminated zone.In response to metal stress,elevation in antioxidant enzyme activities,increases in the PCs and GSH levels in the aerial parts,and metal storage within vacuoles counteracted each other in the invasion mechanism of Z.fabago.

  11. Pequi leaves incorporated into the soil reduce the initial growth of cultivated, invasive and native species

    Directory of Open Access Journals (Sweden)

    LAÍSA N. ALLEM

    2014-12-01

    Full Text Available Studies have identified the phytotoxicity of many native species of the Cerrado; however, most of them were conducted either in inert substrates, or using exaggerate proportions of plant material. We investigated the phytotoxicity of pequi leaves added to substrate soil in quantities compatible with the litter produced by this species. Pequi leaves were triturated and added to red latosol in concentrations of 0.75%, 1.5% and 3%; the control was constituted of leafless soil. These mixtures were added to pots and irrigated daily to keep them moist. Germinated seeds of the cultivated sorghum and sesame, of the invasive brachiaria and of the native purple ipê, were disposed in the pots to grow for five to seven days at 30°C within a photoperiod of 12 h. Seedlings of all the species presented a reduction in their initial growth in a dose-dependent way. In general, the root growth was more affected by the treatments than the shoot growth; moreover, signs of necrosis were observed in the roots of the sorghum, sesame and brachiaria. The phytotoxic effects generated by relatively small quantities of leaves, in a reasonable range of species within a soil substrate, suggest potential allelopathy of pequi leaves under natural conditions.

  12. [Biological factors influencing infectious diseases transmitted by invasive species of mosquitoes].

    Science.gov (United States)

    Boštíková, Vanda; Pasdiorová, Markéta; Marek, Jan; Prášil, Petr; Salavec, Miloslav; Sleha, Radek; Střtítecká, Hana; Blažek, Pavel; Hanovcová, Irena; Šošovičková, Renáta; Špliňo, Milan; Smetana, Jan; Chlíbek, Roman; Hytych, Václav; Kuča, Kamil; Boštík, Pavel

    2016-06-01

    Studies focused on arbovirus diseases transmitted by invasive species of mosquitoes have become increasingly significant in recent years, due to the fact that these vectors have successfully migrated to Europe and become established in the region. Mosquitoes, represented by more than 3 200 species, occur naturally worldwide, except in Antarctica. They feed on the blood of warm-blooded animals and by this route, they are capable of transmitting dangerous diseases. Some species can travel a distance of 10 km per night and can fly continuously for up to 4 hours at a speed of 1-2 km/h. Most species are active at night, in the evening or morning. It usually takes a mosquito female about 50 seconds to penetrate the skin of mammals and the subsequent blood meal usually takes about 2.5 minutes. Mosquitoes live for several weeks or months, depending on the environmental conditions. The VectorNet project is a European network of information exchange and sharing of data relating to the geographical distribution of arthropod vectors and transmission of infectious agents between human populations and animals. It aims at the development of strategic plans and vaccination policies which are the main tasks of this time, as well as the development and application of new disinfectants to control vector populations.

  13. Biology and new records of the invasive species Branchiomma bairdi (Annelida: Sabellidae in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    A. ARIAS

    2013-04-01

    Full Text Available First observations on the reproductive biology of the alien polychaete Branchiomma bairdi (McIntosh, 1885 (Sabellidae in the Mediterranean Sea are provided as well as additional Mediterranean records of the species which can help to understand its introduction and spreading. Re-examination of the specimens from Miseno harbour (Tyrrhenian Sea, Italy revealed the presence of B. bairdi in the central-Mediterranean since September 2004. The histological study of individuals collected in Malta revealed that the species is a simultaneous hermaphrodite, developing male and female gametes in the same body segments; embryos are brooded inside the parent tube. However, there is evidence also for asexual reproduction. The species shows a different reproductive pattern from the previously reported population from the eastern-Pacific; this demonstrates its great plasticity and adaptability. Branchiomma bairdi has an invasive behaviour, colonizing large areas in relatively short-time, and reaching relatively high densities (c.a. 50 individuals/m2. Its expansion throughout several Mediterranean localities is largely a consequence of the high capacity of this species to colonize extremely different habitats and substrates, to the occurrence of sexual and asexual reproductive strategies, and the combination of both. Further, B. bairdi appears to be particularly abundant in confined and anthropogenic degraded areas. Finally, our findings strongly suggest that the pathway of introduction in the Mediterranean, previously hypothesized as the Suez Canal (Lessepsian migration, is most likely via the Gibraltar Strait.

  14. Contaminant concentrations in Asian carps, invasive species in the Mississippi and Illinois Rivers.

    Science.gov (United States)

    Rogowski, D L; Soucek, D J; Levengood, J M; Johnson, S R; Chick, J H; Dettmers, J M; Pegg, M A; Epifanio, J M

    2009-10-01

    Populations of invasive fishes quickly reach extremely high biomass. Before control methods can be applied, however, an understanding of the contaminant loads of these invaders carry is needed. We investigated differences in concentrations of selected elements in two invasive carp species as a function of sampling site, fish species, length and trophic differences using stable isotopes (delta (15)N, delta (13)C). Fish were collected from three different sites, the Illinois River near Havana, Illinois, and two sites in the Mississippi River, upstream and downstream of the Illinois River confluence. Five bighead carp (Hypophthalmichthys nobilis) and five silver carp (Hypophthalmichthys molitrix) from each site were collected for muscle tissue analyses. Freshwater mussels (Amblema plicata) previously collected in the same areas were used as an isotopic baseline to standardize fish results among sites. Total fish length, trophic position, and corrected (13)C, were significantly related to concentrations of metals in muscle. Fish length explained the most variation in metal concentrations, with most of that variation related to mercury levels. This result was not unexpected because larger fish are older, giving them a higher probability of exposure and accumulation of contaminants. There was a significant difference in stable isotope profiles between the two species. Bighead carp occupied a higher trophic position and had higher levels of corrected (13)C than silver carp. Additionally bighead carp had significantly lower concentrations of arsenic and selenium than silver carp. Stable isotope ratios of nitrogen in Asian carp were at levels that are more commonly associated with higher-level predators, or from organisms in areas containing high loads of wastewater effluent.

  15. Development of an invasive species distribution model with fine-resolution remote sensing

    Science.gov (United States)

    Diao, Chunyuan; Wang, Le

    2014-08-01

    Saltcedar (Tamarix spp.) is recognized as one of the most aggressively invasive species throughout the Western United States. Mapping its suitable habitat is of paramount importance to effective management, and thus, becomes a high priority for conservation practitioners. In previous studies, species distribution models (SDMs) have been applied to predicting the suitable habitats of saltcedar at national scale, but at coarser spatial resolution (1 km). Although such studies achieved some success, they are lacking of capability to accommodate fine-scale resolution environmental variables, and therefore, fail to uncover detailed spatial pattern of habitats. The objective of this study was to develop a remote sensing driven SDM so as to characterize suitable habitats of saltcedar at very fine spatial scale (30 m). We exploited several fine-scale environmental predictors through remote sensing images, and utilized the logistic regression model to analyze the species-habitat relationship by identifying influential factors with subset selection criteria. We also incorporated the spatial autocorrelation with regression kriging method. Our results indicated that the model incorporating spatial autocorrelation achieved a higher accuracy than that of regression only model. Among 10 environmental variables, the distance to the river and the phenological attributes summarized by the harmonic analysis were regarded as the most significant in predicting the invasive potential of saltcedar. We conclude that remote sensing driven SDM has potential to identify the suitable habitat of saltcedar at a fine scale and locate appropriate areas at high risk of saltcedar infestation, which could benefit the early control and proactive management strategies to a large extent.

  16. Enhancing the effectiveness of biological control programs of invasive species through a more comprehensive pest management approach.

    Science.gov (United States)

    DiTomaso, Joseph M; Van Steenwyk, Robert A; Nowierski, Robert M; Vollmer, Jennifer L; Lane, Eric; Chilton, Earl; Burch, Patrick L; Cowan, Phil E; Zimmerman, Kenneth; Dionigi, Christopher P

    2017-01-01

    Invasive species are one of the greatest economic and ecological threats to agriculture and natural areas in the US and the world. Among the available management tools, biological control provides one of the most economical and long-term effective strategies for managing widespread and damaging invasive species populations of nearly all taxa. However, integrating biological control programs in a more complete integrated pest management approach that utilizes increased information and communication, post-release monitoring, adaptive management practices, long-term stewardship strategies, and new and innovative ecological and genetic technologies can greatly improve the effectiveness of biological control. In addition, expanding partnerships among relevant national, regional, and local agencies, as well as academic scientists and land managers, offers far greater opportunities for long-term success in the suppression of established invasive species. In this paper we direct our recommendations to federal agencies that oversee, fund, conduct research, and develop classical biological control programs for invasive species. By incorporating these recommendations into adaptive management strategies, private and public land managers will have far greater opportunities for long-term success in suppression of established invasive species. © 2016 Society of Chemical Industry.

  17. The AquaDEB project (phase I): Analysing the physiological flexibility of aquatic species and connecting physiological diversity to ecological and evolutionary processes by using Dynamic Energy Budgets

    Science.gov (United States)

    Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2009-08-01

    The European Research Project AquaDEB (2007-2011, http://www.ifremer.fr/aquadeb/) is joining skills and expertise of some French and Dutch research institutes and universities to analyse the physiological flexibility of aquatic organisms and to link it to ecological and evolutionary processes within a common theoretical framework for quantitative bioenergetics [Kooijman, S.A.L.M., 2000. Dynamic energy and mass budgets in biological systems. Cambridge University Press, Cambridge]. The main scientific objectives in AquaDEB are i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability of natural or human origin, and ii) to evaluate the related consequences at different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). At mid-term life, the AquaDEB collaboration has already yielded interesting results by quantifying bio-energetic processes of various aquatic species (e.g. molluscs, fish, crustaceans, algae) with a single mathematical framework. It has also allowed to federate scientists with different backgrounds, e.g. mathematics, microbiology, ecology, chemistry, and working in different fields, e.g. aquaculture, fisheries, ecology, agronomy, ecotoxicology, climate change. For the two coming years, the focus of the AquaDEB collaboration will be in priority: (i) to compare energetic and physiological strategies among species through the DEB parameter values and to identify the factors responsible for any differences in bioenergetics and physiology; and to compare dynamic (DEB) versus static (SEB) energy models to study the physiological performance of aquatic species; (ii) to consider different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) to scale up the models for a few species from

  18. Occurrence of the invasive species Corbicula fluminea (Bivalvia, Corbiculidae) in the Sapucaí River (São Paulo, Brazil)

    OpenAIRE

    Vianna, Marina Peixoto; Avelar, Wagner Eustáquio Paiva

    2010-01-01

    Biological invasions are gaining increasing importance due to the ecological damage and economic impacts caused by the invaders. Corbicula fluminea (Müller, 1774) is an invasive exotic bivalve introduced into Brazil in the 1970's, and it has colonized the major rivers of the south and southeast. This species, owing to its adaptations to the environment, speed of colonization and reproductive success among others parameters, quickly occupies the substrates preferred by the natives. The pr...

  19. Invasive Species Guidebook for Department of Defense Installations in the Chesapeake Bay Watershed: Identification, Control, and Restoration

    Science.gov (United States)

    2007-11-01

    floor and prevent growth of other vegetation. It is especially detrimental to native spring wildflowers and their related organisms. Fig buttercup’s...an aggressive, perennial pest of waterways from coastal Virginia to Florida and west to Texas, with a disjunct population in California . It...Invasive Plant Atlas of New England, University of California -Davis database, and Washington State Department of Ecology. 102 INVASIVE SPECIES

  20. The invasive species Ulex europaeus (Fabaceae) shows high dynamism in a fragmented landscape of south-central Chile.

    Science.gov (United States)

    Altamirano, Adison; Cely, Jenny Paola; Etter, Andrés; Miranda, Alejandro; Fuentes-Ramirez, Andres; Acevedo, Patricio; Salas, Christian; Vargas, Rodrigo

    2016-08-01

    Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account

  1. Vulnerability assessment of New Jersey's food supply to invasive species: the New Jersey IMPORT project.

    Science.gov (United States)

    Gregory, Petros; Hamilton, George; Borjan, Marija; Robson, Mark

    2006-01-01

    The United States' environment and economy have been severely impacted by unintentionally introduced biological organisms for the last 100 years. Our ecosystems and biological reserves of conservation importance are regularly invaded by non-indigenous species. To help prevent future invaders from entering the ports, this project undertaken at the Port of Elizabeth proposed to: 1. Catalog the different vegetable and fruit crops entering this country; 2. Evaluate the potential risk to New Jersey crops that an introduced exotic pest might pose; and 3. Evaluate the potential that imported crops entering the U.S. have for harboring exotic pests. The New Jersey IMPORT report, or Invasive Management Promoting Open and Responsible Trade project, details a newly designed ecological risk assessment tool to evaluate entry potential of invasive pests at the Port of Elizabeth. Risk designations were assigned to shipments of four fruits; seven vegetables; and two field/forage crops based on: i) Country of origin; ii) Amounts of commodities imported; and iii) Endemic pests present in exporting countries. Between 5,000 and 180,000 tons of crops were imported into the Port of Elizabeth from October 2001 to 2003. Pest risk analyses were drafted for twenty-five intercepted insects taken from the Port Information Network. In addition, eighteen pest risk analyses were drafted for invasive fungi, bacteria, and viruses of global concern as alerted by ProMed Digest. It was concluded that three crops imported remain at high risk: apples, peppers, and tomatoes. Peaches, soybeans, lettuce, sweet corn, potatoes, squash, and eggplant imported were considered moderate risk. Blueberries, cranberries, and alfalfa were considered low risk.

  2. The effect of competition on the neutral intraspecific diversity of invasive species.

    Science.gov (United States)

    Roques, L; Hosono, Y; Bonnefon, O; Boivin, T

    2015-08-01

    This paper deals with the effect of interspecific competition on the dynamics of neutral genetic diversity in a range-expanding population. The spread of an invasive species in an environment already hosting a resident competitor is described by a traveling wave solution with minimal speed, u(t,x) = U(x - c ∗ t), of a diffusive Lotka-Volterra competition model. The description of the dynamics of neutral genetic fractions in this wave is based on a decomposition of the wave into several components, as proposed by Roques et al. (Proc Natl Acad Sci USA 109(23):8828-8833, 2012). Our analytical results reveal that the wave can be either the pulled type, corresponding to strong erosion of the diversity, or the pushed type, corresponding to maintenance of the initial diversity. The pulled/pushed nature of the wave depends on the linear or nonlinear nature of the speed c *. Our results show that, for sufficiently strong competition, the speed is nonlinear, and therefore all of the genetic diversity in the invasive population is maintained. Conversely, in the absence of competition, or when competition is mild, the speed is linear, which means that only the furthest forward fraction in the initial invasive population eventually remains in the colonization front. Our numerical results also show that the sufficient conditions of Lewis et al. (J Math Biol 45(3):219-233, 2002) and Huang (J Dyn Differ Equ 22(2):285-297, 2010) for the linearity of the speed c * can still be improved, and they show that nonlinear speeds occur across a wide region of the parameter space, providing a counterpoint to recent analytical results suggesting that nonlinear speeds only occur in certain limiting cases.

  3. Integrating subsistence practice and species distribution modeling: assessing invasive elodea’s potential impact on Native Alaskan subsistence of Chinook salmon and whitefish

    Science.gov (United States)

    Luizza, Matthew; Evangelista, Paul; Jarnevich, Catherine S.; West, Amanda; Stewart, Heather

    2016-01-01

    Alaska has one of the most rapidly changing climates on earth and is experiencing an accelerated rate of human disturbance, including resource extraction and transportation infrastructure development. Combined, these factors increase the state’s vulnerability to biological invasion, which can have acute negative impacts on ecological integrity and subsistence practices. Of growing concern is the spread of Alaska’s first documented freshwater aquatic invasive plant Elodea spp. (elodea). In this study, we modeled the suitable habitat of elodea using global and state-specific species occurrence records and environmental variables, in concert with an ensemble of model algorithms. Furthermore, we sought to incorporate local subsistence concerns by using Native Alaskan knowledge and available statewide subsistence harvest data to assess the potential threat posed by elodea to Chinook salmon (Oncorhynchus tshawytscha) and whitefish (Coregonus nelsonii) subsistence. State models were applied to future climate (2040–2059) using five general circulation models best suited for Alaska. Model evaluations indicated that our results had moderate to strong predictability, with area under the receiver-operating characteristic curve values above 0.80 and classification accuracies ranging from 66 to 89 %. State models provided a more robust assessment of elodea habitat suitability. These ensembles revealed different levels of management concern statewide, based on the interaction of fish subsistence patterns, known spawning and rearing sites, and elodea habitat suitability, thus highlighting regions with additional need for targeted monitoring. Our results suggest that this approach can hold great utility for invasion risk assessments and better facilitate the inclusion of local stakeholder concerns in conservation planning and management.

  4. Integrating subsistence practice and species distribution modeling: assessing invasive elodea's potential impact on Native Alaskan subsistence of Chinook salmon and whitefish

    Science.gov (United States)

    Luizza, Matthew W.; Evangelista, Paul H.; Jarnevich, Catherine S.; West, Amanda; Stewart, Heather

    2016-07-01

    Alaska has one of the most rapidly changing climates on earth and is experiencing an accelerated rate of human disturbance, including resource extraction and transportation infrastructure development. Combined, these factors increase the state's vulnerability to biological invasion, which can have acute negative impacts on ecological integrity and subsistence practices. Of growing concern is the spread of Alaska's first documented freshwater aquatic invasive plant Elodea spp. (elodea). In this study, we modeled the suitable habitat of elodea using global and state-specific species occurrence records and environmental variables, in concert with an ensemble of model algorithms. Furthermore, we sought to incorporate local subsistence concerns by using Native Alaskan knowledge and available statewide subsistence harvest data to assess the potential threat posed by elodea to Chinook salmon ( Oncorhynchus tshawytscha) and whitefish ( Coregonus nelsonii) subsistence. State models were applied to future climate (2040-2059) using five general circulation models best suited for Alaska. Model evaluations indicated that our results had moderate to strong predictability, with area under the receiver-operating characteristic curve values above 0.80 and classification accuracies ranging from 66 to 89 %. State models provided a more robust assessment of elodea habitat suitability. These ensembles revealed different levels of management concern statewide, based on the interaction of fish subsistence patterns, known spawning and rearing sites, and elodea habitat suitability, thus highlighting regions with additional need for targeted monitoring. Our results suggest that this approach can hold great utility for invasion risk assessments and better facilitate the inclusion of local stakeholder concerns in conservation planning and management.

  5. Impact of environmentally based chemical hardness on uranium speciation and toxicity in six aquatic species.

    Science.gov (United States)

    Goulet, Richard R; Thompson, Patsy A; Serben, Kerrie C; Eickhoff, Curtis V

    2015-03-01

    Treated effluent discharge from uranium (U) mines and mills elevates the concentrations of U, calcium (Ca), magnesium (Mg), and sulfate (SO4 (2-) ) above natural levels in receiving waters. Many investigations on the effect of hardness on U toxicity have been experiments on the combined effects of changes in hardness, pH, and alkalinity, which do not represent water chemistry downstream of U mines and mills. Therefore, more toxicity studies with water chemistry encountered downstream of U mines and mills are necessary to support predictive assessments of impacts of U discharge to the environment. Acute and chronic U toxicity laboratory bioassays were realized with 6 freshwater species in waters of low alkalinity, circumneutral pH, and a range of chemical hardness as found in field samples collected downstream of U mines and mills. In laboratory-tested waters, speciation calculations suggested that free uranyl ion concentrations remained constant despite increasing chemical hardness. When hardness increased while pH remained circumneutral and alkalinity low, U toxicity decreased only to Hyalella azteca and Pseudokirchneriella subcapitata. Also, Ca and Mg did not compete with U for the same uptake sites. The present study confirms that the majority of studies concluding that hardness affected U toxicity were in fact studies in which alkalinity and pH were the stronger influence. The results thus confirm that studies predicting impacts of U downstream of mines and mills should not consider chemical hardness. Environ Toxicol Chem 2015;34:562-574. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of SETAC.

  6. Oxidation of diclofenac with chlorine dioxide in aquatic environments: influences of different nitrogenous species.

    Science.gov (United States)

    Wang, Yingling; Liu, Haijin; Liu, Guoguang; Xie, Youhai; Ni, Tianjun

    2015-06-01

    The oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug and emerging water pollutant, with chlorine dioxide was investigated under simulated water disinfection conditions. The reaction kinetics as functions of the initial concentrations of DCF, different nitrogenous species, and different pE values were experimentally determined. The results demonstrated that DCF reacted rapidly with ClO2, where more than 75 % of DCF (≤3.00 μM) was removed by 18.94 μM ClO2 within 60 s. All of the reactions followed pseudo first-order kinetics with respect to DCF, and the rate constant, k obs, exhibited a significant decrease from 4.21 × 10(-2) to 8.09 × 10(-3) s(-1), as the initial DCF concentration was increased from 1.00 to 5.00 μM. Furthermore, the degradation kinetics of DCF was clearly dependent on nitrogen-containing ion concentrations in the reaction solution. Ammonium and nitrite ions inhibited the DCF degradation by ClO2, whereas nitrate ion clearly initiated its promotion. In contrast, the inhibitory effect of NO2 (-) was more robust than that of NH4 (+). When the values of pE were gradually increased, the transformation of NH4 (+) to NO2 (-), and subsequently to NO3 (-), would occur, the rate constants were initially decreased, and then increased. When NH4 (+) and NO2 (-) coexisted, the inhibitory effect on the DCF degradation was less than the sum of the partial inhibitory effect. However, when NO2 (-) and NO3 (-) coexisted, the actual inhibition rate was greater than the theoretical estimate. These results indicated that the interaction of NH4 (+) and NO2 (-) was antagonistic, while the coexistence of NO2 (-) and NO3 (-) was observed to have a synergistic effect in aqueous environments.

  7. Chemical species of metallic elements in the aquatic environment of an ex-mining catchment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Ahmad, Mushtaq; Akib, Shatirah; Balkhair, Khaled S; Abu Bakar, Nor Kartini

    2014-08-01

    This study was conducted to investigate the chemical speciation of dissolved and particulate elements (lead, zinc, copper, chromium, arsenic, and tin) in the mining wastewater of a former tin-mining catchment. The speciation patterns of dissolved elements were estimated by an adsorptive stripping voltammeter (ASV), while particulate elements were analyzed by using a newly developed sequential-extraction leaching procedure. The procedure has been operationally defined among five host fractions, namely exchangeable, carbonate, reducible, organic bound, and residual fractions. A total of six elements (lead, zinc, copper, chromium, arsenic, and tin) were analyzed in thirty samples at ten locations (P1-P10), with three samples taken from each of the ten locations, to get the average value from the former tin-mining catchment. The results showed that the heavy metal pollutions in locations P4 and P8 were more severe than in other sampling sites, especially tin and lead pollution. In the water samples from locations P4 and P8, both the total contents and the most dangerous non-residual fractions of tin and lead were extremely high. More than 90% of the total concentrations of arsenic and chromium existed in the residual fraction. Concentrations of copper and zinc mainly occurred in the residual fraction (more than 60%), while lead and tin presented mostly in the non-residual fractions in surface water. For all of the six dissolved elements, the less-labile species formed the predominant fraction in their speciation patterns. The speciation patterns of particulate elements showed that most of the concentrations of zinc, copper, chromium, and arsenic were found in the reducible fraction; whereas lead and tin were mainly associated with the organic fraction.

  8. Aspects Regarding the Installation of Some Invasive Weeds Species on Old Fly Ash Dumps

    Directory of Open Access Journals (Sweden)

    Anca Pricop

    2010-10-01

    Full Text Available Most Romanian power plants were built in a period when environmental impact of their operation was undervalued, and constraints related to environmental protection were relatively few. Location of power plants and fly ash dumps was chosen most often by arbitrary criteria, and never after the impact that it may have on the environment. Building fly ash dumps have an effect of destruction of soils not only on the surface equivalent to those of dumps but also of the contiguous lands. Old fly ash dumps are a major risk because of the dispersion of pollutants in water and soil by percolation and soil leaching, and because of the unwanted invasion of weeds that are adaptable to arid conditions of the dumps and then invade surrounding areas jeopardizing the surrounding crops. In attempting to install vegetation an old fly ash dumps, the area were invaded by two species of weeds that quickly overgrown the experimental parcel and the surroundings. The present study followed the invasion degree of fly ash dumps with weeds and aspects regarding their development and breeding in the new formed ecosystem.

  9. Euphorbia davidii - an invasive weed species in the fields of Serbia

    Directory of Open Access Journals (Sweden)

    Vajgand Dragan K.

    2014-01-01

    Full Text Available Euphorbia davidii Subils (Euphorbiaceae or toothed spurge is a plant native to North America, but in Europe it is an alien weed. The populations of this weed were recorded in the Province of Vojvodina (Serbia for the first time in 2007 in the arable fields in two localities: between the villages of Aleksa Šantić and Pačir and also between the villages of Pačir and Đurđin. There were no previous published data about the occurrence of this species in Serbia, nor about management measures in crops to suppress this agricultural invader. In this paper, we present experiences with several herbicide treatments applied to suppress populations of toothed spurge from the crop fields in Serbia during the last six years. The most effective was treatment with a high concentration of glyphosate in the early phases of toothed spurge growing. The populations of this invasive weed spread and formed more or less dense patches in the crop field, the area of distribution increased from 3 ha to 7 ha. Observations and experiences with treatments suggest that Euphorbia davidii, as an invasive plant, has significant impact on crop fields, therefore further investigation of suppression measures and monitoring of its population is needed.

  10. Effects of the environmental estrogenic contaminants bisphenol A and 17α-ethinyl estradiol on sexual development and adult behaviors in aquatic wildlife species.

    Science.gov (United States)

    Bhandari, Ramji K; Deem, Sharon L; Holliday, Dawn K; Jandegian, Caitlin M; Kassotis, Christopher D; Nagel, Susan C; Tillitt, Donald E; Vom Saal, Frederick S; Rosenfeld, Cheryl S

    2015-04-01

    Endocrine disrupting chemicals (EDCs), including the mass-produced component of plastics, bisphenol A (BPA) are widely prevalent in aquatic and terrestrial habitats. Many aquatic species, such as fish, amphibians, aquatic reptiles and mammals, are exposed daily to high concentrations of BPA and ethinyl estradiol (EE2), estrogen in birth control pills. In this review, we will predominantly focus on BPA and EE2, well-described estrogenic EDCs. First, the evidence that BPA and EE2 are detectable in almost all bodies of water will be discussed. We will consider how BPA affects sexual and neural development in these species, as these effects have been the best characterized across taxa. For instance, such chemicals have been in many cases reported to cause sex-reversal of males to females. Even if these chemicals do not overtly alter the gonadal sex, there are indications that several EDCs might demasculinize male-specific behaviors that are essential for attracting a mate. In so doing, these chemicals may reduce the likelihood that these males reproduce. If exposed males do reproduce, the concern is that they will then be passing on compromised genetic fitness to their offspring and transmitting potential transgenerational effects through their sperm epigenome. We will thus consider how diverse epigenetic changes might be a unifying mechanism of how BPA and EE2 disrupt several processes across species. Such changes might also serve as universal species diagnostic biomarkers of BPA and other EDCs exposure. Lastly, the evidence that estrogenic EDCs-induced effects in aquatic species might translate to humans will be considered.

  11. Effects of the environmental estrogenic contaminants bisphenol A and 17α-ethinyl estradiol on sexual development and adult behaviors in aquatic wildlife species

    Science.gov (United States)

    Bhandari, Ramji K.; Deem, Sharon L.; Holliday, Dawn K.; Jandegian, Caitlin M.; Kassotis, Christopher D.; Nagel, Susan C.; Tillitt, Donald E.; vom Saal, Frederick S.; Rosenfeld, Cheryl S.

    2015-01-01

    Endocrine disrupting chemicals (EDCs), including the mass-produced component of plastics, bisphenol A (BPA) are widely prevalent in aquatic and terrestrial habitats. Many aquatic species, such as fish, amphibians, aquatic reptiles and mammals, are exposed daily to high concentrations of BPA and ethinyl estradiol (EE2), estrogen in birth control pills. In this review, we will predominantly focus on BPA and EE2, well-described estrogenic EDCs. First, the evidence that BPA and EE2 are detectable in almost all bodies of water will be discussed. We will consider how BPA affects sexual and neural development in these species, as these effects have been the best characterized across taxa. For instance, such chemicals have been in many cases reported to cause sex-reversal of males to females. Even if these chemicals do not overtly alter the gonadal sex, there are indications that several EDCs might demasculinize male-specific behaviors that are essential for attracting a mate. In so doing, these chemicals may reduce the likelihood that these males reproduce. If exposed males do reproduce, the concern is that they will then be passing on compromised genetic fitness to their offspring and transmitting potential transgenerational effects through their sperm epigenome. We will thus consider how diverse epigenetic changes might be a unifying mechanism of how BPA and EE2 disrupt several processes across species. Such changes might also serve as universal species diagnostic biomarkers of BPA and other EDCs exposure. Lastly, the evidence that estrogenic EDCs-induced effects in aquatic species might translate to humans will be considered.

  12. EFFECT OF AQUATIC ENVIRONMENT PH ON THE LEVEL OF ECTOPARASITE INFESTATION, PROTEIN AND LYSOZYME CONTENT IN SOME CYPRINID SPECIES (CYPRINIDAE

    Directory of Open Access Journals (Sweden)

    L. Kurovskaya

    2016-03-01

    Full Text Available Purpose. To study the effect of рН values of the aquatic environment on the level of ectoparasite infestation, protein and lysozyme content in organs and serum of some cyprinid species in experimental conditions. Methodology. The objects of the study were yearlings of Cyprinus carpio, Carassius auratus gibelio and Pseudorasbora parva caught in ponds of fish farm “Nyvka” (Kiev region in spring. Fish were kept in experimental conditions at neutral pH water (6.8-7.2 and a temperature of 17-18оC. To study the changes in the level of fish parasite infestation at different pH values, we used carp yearlings, as an object, the most infected with parasites. Fish were placed in aquariums with water pH of 5.0-5.5 (slightly acidic environment and 8.5-9.0 (slightly alkaline environment for 5 days. Thereafter, the ectoparasites were counted on fish body surface and gills. The protein content in serum and tissue extracts of organs (liver, kidney, spleen of Carassius auratus gibelio and Pseudorasbora parva infected and uninfected ectoparasites, after holding them in slightly acidic or slightly alkaline environment for 8 days, was determined by Lowry’s method, while lysozyme content was determined by a diffusion method on agar. Findings. A comparative assessment of the number of ectoparasites (Ichthyophthirius multifiliis, Trichodina sp., Dactylogyrus sp., Gyrodactylus sp. on fish body surface and gills, the content of protein and lysozyme in serum and organs at different pH values of aquatic environment has been presented. It was demonstrated that the number of ectoparasites on fish body surface and gills was significantly reduced when keeping the fish in both slightly acidic and slightly alkaline environments. In infected Carassius auratus gibelio, a reduction in the protein and lysozyme content in liver, kidney and serum was observed only in the neutral pH environment compared to uninfected individuals. In the slightly acidic or slightly alkaline

  13. Invasive species in penguin worlds: An ethical taxonomy of killing for conservation

    Directory of Open Access Journals (Sweden)

    Thom van Dooren

    20