Introduction Of Non-indigenous Species Research Articles

Principles of the Atmospheric Pathway for Invasive Species Applied to Soybean Rust

Abstract Aerial transport alone is seldom responsible for the introduction of nonindigenous species into distant regions; however, the capacity to use the atmospheric pathway for rapid spread in large part determines the invasive potential of organisms once they are introduced. Because physical and biological features of Earth's surface influence the routes and timing of organisms that use the atmospheric pathway, long-distance movement of aerobiota is largely regular and thus predictable. Soybean rust (Phakopsora pachyrhizi), potentially the most destructive foliar disease of soybean, recently invaded North America. The concepts presented in this article form the basis of the soybean rust aerobiology prediction system (SRAPS) that was developed to assess potential pathogen movement from South America to the United States. Output from SRAPS guided the scouting operations after the initial discovery of soybean rust in Louisiana. Subsequent observations of P. pachyrhizi in the southeastern United States pro...

Marine introductions in the Shark Bay World Heritage Property, Western Australia: a preliminary assessment

ABSTRACTThe presence and impacts of non‐indigenous species (NIS) in marine areas of high conservation or World Heritage significance have rarely been examined. Case studies worldwide suggest that the potential exists for the introduction of NIS to significantly impact conservation values in regions conserved for the uniqueness and diversity of native assemblages. In this study, a preliminary investigation was conducted to provide information essential for managing marine introductions in the Shark Bay World Heritage Property. A focused fouling plate survey sampled a total of 112 encrusting taxa, of which 10 (11.2%) were classified as introduced and 10 others as cryptogenic. Eight introduced bryozoans: Aetea anguina (Linnaeus, 1758), Bugula neritina (Linnaeus, 1758), Bugula stolonifera Ryland, 1960, Conopeum seurati (Canu, 1928), Savignyella lafontii (Audouin, 1826), Schizoporella errata (Waters, 1878), Watersipora subtorquata (d’Orbigny, 1842) and Zoobotryon verticellatum della Chiaje, 1828; one tunicate, Styela plicata Lesueur, 1823; and an introduced hydroid, Obelia dichotoma (Linnaeus, 1758) were frequent, and in some cases dominant, components of encrusting communities. Of the 20 most frequently occurring species detected in the Bay, four were introduced and of the 20 species with highest average percent cover per plate, six were introduced. At one site, space occupation by NIS averaged 71.6% ± 7.4 of plate live cover. Space occupation by an individual NIS was as high as 62.4% of plate area (mean 7.82% ± 1.8). NIS were detected at sites lacking commercial traffic and ballast water discharge and isolated by distance and physical environment, suggesting that hull fouling of recreational craft may be the most important vector in the region. Seventy‐five percent of NIS detected in Shark Bay are established in Australian ports to the south of Shark Bay, while 33% are established to the north, tentatively implicating temperate affinity NIS and the movement of vessels from Australian ports south of Shark Bay as a greater risk to the region.

Understanding the Causes of Disease in European Freshwater Crayfish

Abstract: Native European freshwater crayfish (Astacida, Decapoda) are under severe pressure from habitat alteration, the introduction of nonindigenous species, and epizootic disease. Crayfish plague, an acute disease of freshwater crayfish caused by the fungus‐like agent Aphanomyces astaci, was introduced into Europe in the mid‐nineteenth century and is responsible for ongoing widespread epizootic mortality in native European populations. We reviewed recent developments and current practices in the field of crayfish pathology. The severity of crayfish plague has resulted in an overemphasis on it. Diagnostic methods for detecting fungi and fungal‐like agents, and sometimes culturing them, are frequently the sole techniques used to investigate disease outbreaks in European freshwater crayfish. Consequently, the causes of a significant proportion of outbreaks are undetermined. Pathogen groups well known for causing disease in other crustaceans, such as viruses and rickettsia‐like organisms, are poorly understood or unknown in European freshwater crayfish. Moreover, the pathogenic significance of some long‐known pathogens of European freshwater crayfish remains obscure. For effective management of this culturally significant and threatened resource, there is an urgent need for researchers, diagnosticians, and resource managers to address the issue of disease in European freshwater crayfish from a broader perspective than has been applied previously.

BACKCASTING AND FORECASTING BIOLOGICAL INVASIONS OF INLAND LAKES

Human introduction of nonindigenous species constitutes a serious threat to many ecosystems, particularly lakes. Recent attempts to predict invasions have focused on the supply of propagules of nonindigenous species to recipient ecosystems from source populations. Here we develop a spatially explicit “gravity” model to test this concept forBythotrephes longimanus, a crustacean waterflea from Eurasia that is rapidly invading lakes in Ontario, Canada. The gravity model predicted spread ofBythotrephesbased upon seven identified risk factors (e.g., use of contaminated fishing or boat anchor line) that may allow dispersal of either live individuals or their resting eggs from invaded to noninvaded lakes, as well as based on the spatial arrangement of invaded and noninvaded lakes in Ontario. Discriminant analysis of lake gravity scores successfully identified invasion status for 74% of 170 inland lakes. A retrospective analysis of 31 invaded lakes revealed that the order in which lakes were invaded was directly related to the magnitude of vector inflows from invaded sources. Analysis of the dominant vector inflow to each invaded lake revealed a “stepping stone” pattern in which at least five lakes were sequentially invaded from the source population in Lake Huron. One invaded lake (Muskoka) apparently served as an invasion “hub,” resulting in up to 18 additional direct and 17 indirect invasions. Species spread occurred via a combination of dominant, local diffusion (median distance 12.5 km) and rare, long‐distance (>100 km) dispersal. Eleven of 131 lakes that were not invaded in 2000 were reported invaded in 2001. Gravity scores of these lakes were significantly higher than those of other noninvaded systems, indicating that susceptibility to invasion can be related to the magnitude of vector inflows. A GIS model based on gravity scores indicated that distribution ofBythotrephesis expected to expand to eastern and northwestern Ontario, although most new invasions are expected to occur in the central region of the province. Our results indicate that quantitative analysis of human dispersal vectors provides a robust starting point with which to assess vulnerability of discrete ecosystems to invasion. Management efforts focused on reducing the number and magnitude of human‐mediated dispersal vectors may reduce the rate of invasion of new ecosystems.

SYNOPTIC MAPPING OF SHALLOW, MARINE, COASTAL COMMUNITIES USING AIRBORNE HYPERSPECTRAL SENSORS: TECHNICAL ASPECTS, OPERATIONAL APPROACHES, AND PROVEN APPLICATIONS

The integrity of littoral ecosystems is seriously threatened by the sustained and evergrowing exploitation of coastal resources by humankind, the introduction of non indigenous species, and the ongoing climate change. The concurrent exploitation and preservation of coastal ecosystems is a major challenge, which can only be effectively addressed using synoptic tools and approaches for detailed mapping and monitoring of subtidal communities. One of the most promising technologies to this end is the use of airborne hyperspectral remote sensing technologies that feature both high spectral and spatial resolutions. This paper provides an overview of the technical aspects and operational approaches to map the extent of shallow, marine, coastal habitats over large scales using the compact airborne spectrographic imager (casi). The applicability of this approach is demonstrated through a review of recent subtidal mapping projects conducted by Hyperspectral Data International in tropical and temperate zones

Role of Technology in Achieving Environmental Policy Goals in the Maritime Transportation System

The maritime transportation system (MTS), a truly multimodal industry, is in the unique position of being able to implement technologies borrowed from other areas and combine them with innovations developed within the industry to achieve continued advancement. There is an increasing need for better environmental performance in the industry; this is generally accomplished through new or adopted technologies. Previous research has explored the independent ideas of individual technological or environmental policy achievements. The role of technology in achieving environmental policy goals in the marine shipping industry is addressed, and the efficacy of various types of environmental policy mechanisms in promoting appropriate technologies is considered. Two case studies involving the environmental impacts associated with MTS (air pollution and nonindigenous species introductions) are evaluated. These two environmental problems were initially regulated with environmental standards but have shown a potential for being addressed with more innovative policy approaches. A better understanding of how the industry creates and diffuses technologies and the manner in which various policy mechanisms promote these activities could lead to more effective long-term solutions for environmental improvements.

Teaching Environmental Ethics: Non-indigenous Invasive Species As A Study of Human Relationships to Nature

AbstractThis paper uses the question, "what ethical issues inform our response to nonindigenous invasive species?" as a basis to explore human relationships to nature in the context of teaching environmental ethics. While ecologists express increasing concern about the introduction of non-indigenous invasive species (NIS), the public is sometimes unaware of, or ambivalent about, the problems they cause. I argue that this ambivalence stems from conceptual problems—about human-nature relationships, about ethical conflict and about human behavior—that can be addressed in a course on environmental ethics. Such a course can look at NIS in the context of different ethical traditions, and the different bases for action (or not) with regard to NIS that such ethical traditions imply. I suggest ways to use NIS as case studies in either a science course or an environmental ethics course, to introduce fundamental questions and to explore basic worldviews with respect to humans and nature.

Bridging Troubled Waters: Biological Invasions, Transoceanic Shipping, and the Laurentian Great Lakes

Abstract Release of contaminated ballast water by transoceanic ships has been implicated in more than 70% of faunal nonindigenous species (NIS) introductions to the Great Lakes since the opening of the St. Lawrence Seaway in 1959. Contrary to expectation, the apparent invasion rate increased after the initiation of voluntary guidelines in 1989 and mandatory regulations in 1993 for open-ocean ballast water exchange by ships declaring ballast on board (BOB). However, more than 90% of vessels that entered during the 1990s declared no ballast on board (NOBOB) and were not required to exchange ballast, although their tanks contained residual sediments and water that would be discharged in the Great Lakes. Lake Superior receives a disproportionate number of discharges by both BOB and NOBOB ships, yet it has sustained surprisingly few initial invasions. Conversely, the waters connecting lakes Huron and Erie are an invasion hotspot despite receiving disproportionately few ballast discharges. Other vectors, includ...

Comparative Efficacy of Potential Chemical Disinfectants for Treating Unballasted Vessels

The release of ballast water from transoceanic vessels is a major vector for the introduction of nonindigenous species into the Laurentian Great Lakes. This study assessed the effectiveness of treating unballasted transoceanic vessels using three different biocides: glutaraldehyde plus a surfactant adjuvant (Disinfekt 1000 ®), sodium hypochlorite (NaOCl), and SeaKleen™ (menadione and menadione metabisulfite 2:8). Efficacy against several classes of aquatic organisms was evaluated using 24 h acute toxicity experiments and 11 day ballast tank simulation experiments. The results indicate substantial, compound-specific variations in organism sensitivity. For water-only exposures, NaOCl and SeaKleen™ were most effective: NaOCl had the lowest LC 90 (90% lethal concentration value) for the oligochaete Lumbriculus variegatus (1.0 mg L −1), while SeaKleen™ had the lowest LC 90 for the amphipod Hyalella azteca (2.5 mg L −1). Sediments profoundly affected efficacy, particularly for NaOCl: At a 1:4 sediment-water ratio, the estimated LC 90 for L. variegatus was > 2,000 mg L −1. Sediment quality also impacted efficacy: Sediments with higher organic carbon content typically required greater biocide concentrations to achieve comparable toxicity. Efficacy was further evaluated with 11 day bioassays using sediments from unballasted vessels. Results indicated that NaOCl and Disinfekt 1000 ® were more effective than predicted based on small scale sediment-water exposures. Overall, the data suggest that although NaOCl may be effective under water-only conditions, the higher concentrations required in the presence of sediments may cause corrosion problems for ballast tanks. Because of this, less reactive, non-oxidizing biocides such as SeaKleen™ and Disinfekt 1000 ® may be better candidates for treating sedimented tanks.

Viability of invertebrate diapausing eggs collected from residual ballast sediment

Natural or anthropogenic movement of sediments may be an important vector for the dispersal of invertebrate resting stages between water bodies. Here we record the presence of invertebrate diapausing eggs in residual sediments from transoceanic vessels and explore whether these may pose an invasion risk. Viability of diapausing eggs was explored under light and dark conditions using sediment collected from eleven tanks on nine vessels operating on the Great Lakes. Seventeen cladoceran, copepod, and rotifer taxa were identified. Four of the species hatched have not yet been reported as established in the Great Lakes. Egg viability for individual species varied from 0% to 92%. Exposure to saline water may impact egg viability of some freshwater species. Generally, the proportion of eggs hatched in light and dark treatments did not differ significantly, indicating that light was not required to terminate diapause. As a result, eggs could potentially hatch in dark ballast tanks when immersed in freshwater loaded as ballast during operation on the Great Lakes. Viability of diapausing eggs differed among ballast tanks on a single vessel, indicating that tanks with independent ballast histories have different invasion risks. While additional work is needed to quantify risk, results from this study indicate that vessels entering the Great Lakes with only residual ballast are a potential vector for the introduction of new nonindigenous species during multiport operations.

Interactions of Atlantic salmon in the Pacific Northwest: IV. Impacts on the local ecosystems

The paper begins with the introduction of Atlantic salmon into the local ecosystems of the Pacific Northwest (Puget Sound), and describes potential interactions with native salmonids. Specific sections review possible hybridization between Atlantic and Pacific salmon, genetic dilution and alteration of the gene pool, the colonization of the aquatic environment by Atlantic salmon, and finally the interactions of wild salmon and genetically altered transgenics. This is followed by possible epidemics and transmission of waterborne disease, and reviews the potential for cultured Atlantic salmon, a non-native species, to introduce new diseases into the local ecosystem. There are nine specific items, from the diseases which might be involved, to potential interactions, and current policies for disease control. After a review of the potential ecological impacts in the Pacific Northwest, specifically the interaction with Pacific salmon and predation, there are three parts on the effects of artificial propagation practices in the region in general, the impacts of the introduction of various non-indigenous salmonid species, and a comparison of escapes or releases of propagated Atlantic and Pacific salmon. The last part examines the potential effects of Atlantic salmon vis-à-vis the Biological Status Reviews of west coast Pacific salmon stocks carried out by the National Marine Fisheries Service. The review ends by summarizing the varying degrees of risk carried by these issues.

On the pattern of discovery of introduced species.

Introductions of nonindigenous species can have significant effects. It is commonly claimed that the rate of species introductions to the United States has increased over time. This claim is based in part on the increasing rate of discoveries of introduced species. This discovery rate is influenced by factors other than the introduction rate. These include the sampling rate and population growth in the introduced species. In this article, we show that the discovery rate can increase even when there is no increase in either the introduction rate or the sampling rate. This suggests that the basis for some claims regarding an increasing rate of introductions may be invalid.

Biological pollutants and biological pollution––an increasing cause for concern

There are increasing concerns regarding the delivery, movement and presence of non-indigenous or invasive species into marine and estuarine areas. Such introductions can be on a large scale such as the movement to higher latitudes of species as the result of global warming. Alternatively, such species can be introduced into a marine or estuarine area as the result of small-scale events, such as the liberation from waste-water discharges, aquaculture or ballast-water discharge. However, if such introductions lead to a successful colonisation then they can become a wide-scale problem. This paper considers the introduction of such non-indigenous and invasive species as biological pollution and biological pollutants and it discusses the definitions and concepts used in assessing and managing marine pollution in relation to these terms.

Considerations in the Design of the Primary Treatment for Ballast Systems

Investigations are currently underway to establish effective primary and secondary ballast water treatment methods to minimize the potential for the introduction of additional nonindigenous aquatic species into the Great Lakes and other U.S. coastal waters. This treatment could be used in place of mid-ocean ballast exchange currently required by the U.S. Coast Guard for all vessels entering the Great Lakes in ballast from beyond the Exclusive Economic Zone (EEZ). Primary and secondary treatment could provide environmental protection for both Ballast On Board (BOB) vessels, which are required to perform mid-ocean ballast exchange before entering the Great Lakes, and No Ballast On Board (NOBOB) vessels, which are currently exempt from any ballast exchange requirements. Primary treatment using some form of mechanical separation to 100 urn or 50 um followed by secondary treatment using 254 nm UV irradiation or some form of chemical treatment are currently leading candidates. Over the past six years, the Great Lakes Ballast Technology Demonstration Project (GLBTDP) has undertaken the full-scale evaluation of 340 m3/h (1500 U.S. gpm) ballast water mechanical separation using an automatic backwashing screen filter, hydrocyclone, and automatic backwashing disk filter. This experience provides the basis for the investigation of various ballast system design issues that must be considered in the selection and design of the primary ballast water treatment. This investigation is based upon the ballast system of a typical Seaway size bulk carrier using port and starboard 2000 m3/h (8800 U.S. gpm) main ballast pumps. A discrete multicriterion optimization tradeoff study using the Analytical Hierarchy Process (AHP) is also presented to illustrate a rational method for determining the best choice for primary ballast water treatment for such a Seaway size bulk carrier.

NIS, WTO, SPS, WIR*: Does the WTO Substanstially Limit the Ability of Countries to Regulate Harmful Non-Indigenous Species?

Do global trade regimes restrict countries from passing and enforcing their own strong domestic environmental standards? This Essay attempts to reign in the issue of the relationship between trade and domestic environmental policy by focusing on one test case - the new area of regulating harmful invasive species - and then asking whether current global trade regimes, and in particular the World Trade Organization (WTO) Agreement, would prevent the United States (or any other country) from implementing protective new laws and policies to address this new environmental concern. Part I sketches the new recognition in the United States (mirrored by increased awareness elsewhere) of the substantial environmental and economic threats posed by the introduction and spread of harmful non-indigenous species, and summarizes current proposals to develop new policies in this area. The proposals include recommendations that would impose additional barriers to trade. Part II focuses on the part of the WTO Agreement most likely to be the basis for challenging such a policy. The third part considers whether the WTO regime encourages a sound balance between encouraging rational policymaking and respecting national policies and preferences with regard to the environment (and to the health, safety, and welfare of its citizens more generally). The final Part asks whether challenges to an aggressive U.S. invasive species policy would be likely to succeed, and notes important structural limitations on the WTO process that make the answer hard to predict.

Full Scale Particle Removal Performance of Three Types of Mechanical Separation Devices for the Primary Treatment of Ballast Water

The Great Lakes Ballast Technology Demonstration Project has undertaken a multi-year program to demonstrate and evaluate ballast treatment methodologies that might minimize the potential for the introduction of additional nonindigenous aquatic species into the Great Lakes and other U.S. waters. Full-scale mechanical and biological testing of primary and secondary treatment options has been performed on both operating vessels and a ballast treatment testing barge facility located in Duluth and Two Harbors, Minnesota. Mechanical testing results for three candidate primary mechanical separation devices obtained over a four-year period on the barge installation are presented and compared. Results are presented for the particle removal efficiency at a nominal 340 m3 /h (1500 U.S. gpm) for a 50 micron (µm) screen-type surface automatic backwash filter, a 100 µm rated cyclonic separation device, and a 100 µm disk-type depth automatic backwash filter. The screen-type and disk-type automatic backwash filters showed particle removal efficiencies at and above their removal rating of over 90%. Although more complicated, the disk-type depth filter exhibited a significant advantage through a longer time between backwash cycles and, thus, a greater net filtration throughput. The hydrocyclone demonstrated significantly lower effectiveness (about 30%) in removing particles that included both neutrally buoyant biota and other materials such that, while much simpler, these devices are not considered appropriate for this application requiring the effective removal of both particulate material and larger biota.

Nonindigenous species introductions: a threat to Canada's forests and forest economy1

When organisms are moved from their natural range to new ecosystems, they are considered nonindigenous, invasive, or exotic species. Movement of exotic or native species may be international or from areas within Canada. Historically, Canada's forests have felt the effects of nonindigenous species introductions, as for example, Dutch elm disease, white pine blister rust, gypsy moth, and pine shoot beetle. With changes in global trade patterns, novel introductions will continue to occur. Although most of the research and regulatory efforts to control the movement of nonindigenous species has focused on insects, projects are underway to study fungal organisms and their association with insect vectors. International quarantine standards are being developed to minimize the risk associated with solid wood packing materials, a major entry pathway for nonindigenous organisms. Research needs include the development of enhanced detection capabilities, improved diagnostic tools, effective mitigation measures, as well as socio-economic impact assessments and basic biological information about nonindigenous species and their interactions with hosts.

The loss of native biodiversity and continuing nonindigenous species introductions in freshwater, estuarine, and wetland communities of Pearl Harbor, Oahu, Hawaiian Islands

The benthic invertebrates and fishes of the estuarine, lower stream areas, and wetlands of Pearl Harbor were sampled from 1997–1998 as a companion study to marine inventories conducted in Pearl Harbor. The first comprehensive assessment of the area found that nonindigenous species comprise the dominant portion of the biota. A total of 191 aquatic species in 8 phyla were identified in the estuarine reaches of Pearl Harbor. Nonindigenous species dominated and comprised 48% of the species, whereas only 33% were native and 19% were cryptogenic. Two new nonindigenous species to Hawaii were found during this study: a species of fang-toothed blenny (Omobranchus ferox) and an estuarine hydrobiid snail (Pyrgophorus cf.coronatus) introduced from the Philippine Islands and the Caribbean, respectively. No single geographic region predominates as a source of aquatic species introductions into the Pearl Harbor area, although more species come from the Americas than other areas. Fifty-seven percent originated from the Americas, 30% from Asia and the Pacific, 5% from Australia/New Zealand, 5% show a world-wide distribution, and fewer than 3% of species originated from Africa. The majority of nonindigenous species appear to arrive from five major sources: intentional and accidental aquarium releases; intentional biocontrol releases; intentional food source releases; ballast water or hull fouling releases; and brought in with airplanes. Non-native species will likely continue to increase in the freshwater and estuarine portions Pearl Harbor because of the wide variety of sources from which introductions take place.

Importance of hybridization between indigenous and nonindigenous freshwater species: an overlooked threat to North American biodiversity.

Biodiversity of North American freshwaters is among the greatest in the world. However, due to extensive habitat degradation, pollution, and introductions of nonindigenous species, this biodiversity is also among the most endangered. Unlike habitat degradation and pollution, nonindigenous species represent a permanent loss of biodiversity because their removal or control is often impossible. Most species introduced into nonnative North American ranges, however, are not from Eurasia but have been introduced from geographically isolated regions within North America. Although the ecological effects of introduced species have been widely documented, the effects of hybridization, especially between closely related species, represents an equally serious mechanism of extinction but is much less studied. Identification of which species are likely to hybridize after contact is of critical importance to prevent the further loss of native species. Molecular phylogenetics serves as a powerful tool to identify freshwater species at risk of introgression, if we can assume that genetic distance is a good predictor of the potential for hybridization. Although not a thorough review of all cases of hybridization, this article documents the extent and effects of hybridization in fishes, crayfishes, mussels, and other invertebrates in light of the currently accepted phylogenetic relationships. We suggest this approach may be the first step in addressing the potential threat of hybridization between many of the closely related species in North American fresh waters.

Ship ballast water ultrasonic treatment

Ballast water is treated by applying ultrasonic frequencies to the water to kill organisms entrained in the water such as diatoms, veligers, fish larvae, plankton, and microorganisms, preventing the introduction of non-indigenous species between ports-of-call. The ballast water is circulated through a ballast treatment system. A pump is connected to a tube lined with a piezoelectric material for aiding in transmitting the ultrasonic frequencies connected to one or more ballast tanks of a ship. The use of the piezoelectric material as a lining allows a broad range of sound wavelengths and energy levels to be transmitted greater distances before problems with uniform sound penetration and energy loss within the sound field occur. Additionally, spatially-controllable, continuous constructive interference zones may be generated within the piezoelectric-lined tubes to specifically target the particular organisms entrained within the ballast water being treated. The treatment system includes a transducer pipe connected to diffusers and shrouds. The diffusers are closed at ends not connected to the pipe. The treatment system is provided in the ballast intake/drain device to route the ballast water through the treatment system. Ballast water is supplied through inlets in the shrouds into the diffuser which circulate the water through the tube which is lined with piezoelectric transducer material and then exhausted after treatment. The ultrasonic waves destroy organisms and prevent transfer of non-indigenous species between ports.