Forecasting the Vulnerability of Lakes to Aquatic Plant Invasions (original) (raw)
Related papers
2015
Effective monitoring, prevention and impact mitigation of nonindigenous aquatic species relies upon the ability to predict dispersal pathways and receiving habitats with the greatest risk of establishment. To examine mechanisms affecting species establishment within a large lake, we combined observations of recreational boater movements with empirical measurements of habitat suitability represented by nearshore wave energy to assess the relative risk of Eurasian watermilfoil (Myriophyllum spicatum) establishment. The model was evaluated using information from a 17 year (1995–2012) sequence of M. spicatum presence and absence monitoring. M. spicatum presence was not specifically correlated with recreational boater movements; however its establishment appears to be limited by wave action in Lake Tahoe. Of the sites in the “High” establishment risk category (n = 37), 54% had current or historical infestations, which included 8 of the 10 sites with the highest relative risk. Of the 11 sites in the “Medium” establishment risk category, 5 had current or historical M. spicatum populations. Most (76%) of the sites in the “Low” establishment risk category were observed in locations with higher wave action. Four sites that received zero boater visits from infested locations were occupied by M. spicatum. This suggests that the boater survey either represents incomplete coverage of boater movement, or other processes, such as the movement of propagules by surface currents or introductions from external sources are important to the establishment of this species. This study showed the combination of habitat specific and dispersal data in a relative risk framework can potentially reduce uncertainty in estimates of invasion risk.
Hydrobiologia, 2006
North America has a growing problem with invasive aquatic plants. At every level of the aquatic food web, long-standing checks and balances have become dramatically eroded by the introduction of non-native species. The northeastern United States contains thousands of diverse freshwater habitats, highly heterogeneous in geology and locale, where nuisance aquatic plant growth results in decreased lake water quality, interference with recreational access, degraded flood control structures, and impacts to their aesthetic quality. Early infestation and spread of exotic species is often poorly documented at local and state levels. Consequently, successful management of these species depends on continuous monitoring and definitive identification by both public officials and waterside homeowners. With new mapping capabilities employing software such as Geographic Information Systems (GIS) coupled with the growing computerization of taxonomic records and online availability of regional herbarium records, we have been able to illustrate the temporal and geographic spread of these species, thus enabling aquatic ecologists and managers to make predictions of future infestations. In this paper we evaluate these techniques focusing on three of the most pervasive of exotic aquatic plant species in New York State: Myriophyllum spicatum, Trapa natans and Potamogeton crispus.
Management of Biological Invasions, 2015
Species introduced to the Great Lakes region through shipping, pet and nursery trade, and as biological control have caused significant environmental damages and have increased the direct and indirect costs to boat owners and various water-dependent industries. Once established, recreational boating becomes the primary vector of spread for some of these species, such as zebra mussels (Dreissena polymorpha Pallas, 1771). Prevention and mitigation efforts in the past have focused on boater education, boat washing stations, and inspections; yet these management actions can be expensive with limited or largely unknown effectiveness. In this study, we used a gravity model framework to accurately simulate the spread of an aquatic invasive species. After parameterization, the constructed model effectively simulated the human-mediated movements of the historical dreissenid spread patterns, correctly predicting an average accuracy of 78.2% (standard deviation = 0.01%) lakes invaded per model run.
Invasive Plant Science and Management, 2008
Riparian habitats are important components of an ecosystem; however, their hydrology combined with anthropogenic effects facilitates the establishment and spread of invasive plant species. We used a maximum-entropy predictive habitat model, MAXENT, to predict the distributions of five invasive plant species (Canada thistle, musk thistle, Russian olive, phragmites, and saltcedar) along the North Platte River in Nebraska. Projections for each species were highly accurate. Elevation and distance from river were most important variables for each species. Saltcedar and phragmites appear to have restricted distributions in the study area, whereas Russian olive and thistle species were broadly distributed. Results from this study hold promise for the development of proactive management approaches to identify and control areas of high abundance and prevent further spread of invasive plants along the North Platte River. Nomenclature: Canada thistle, Cirsium arvense (L.) Scop.; common reed, Phragmites australis (Cav.) Trin. ex Steud.; musk thistle, Carduus nutans L.; saltcedar, Tamarix sp. L.; Russian olive, Elaeagnus angustifolia L.
Predicting the Likelihood of Eurasian Watermilfoil Presence in Lakes, a Macrophyte Monitoring Tool
Ecological Applications, 2000
In regions with abundant and diverse freshwater resources, it is difficult and costly to survey all lakes at the level required to detect invasive plants. Effective allocation of monitoring resources requires tools that identify waterbodies where exotic species are most likely to invade. We developed and tested models that predict conditions in which Eurasian watermilfoil, Myriophyllum spicatum, is most likely to survive and successfully colonize. We used logistic regression to model the likelihood of M. spicatum presence or absence using a suite of biological, chemical, and physical lake characteristics which are easily obtainable from public databases. We evaluated model fit by the Aikake criterion and model performance by the percentage of misclassification errors as well as the costs associated with acquiring data for variables modeled. Several models fit our data well, misclassifying only 1.3-11.0% of the lakes where M. spicatum was observed, and used relatively inexpensive landscape variables (percent forest cover in a drainage basin, presence and type of public boat launch, and bedrock type) that typically exist as information layers in geographic information systems (GISs) or recreational atlases. We found that the most important factors affecting the presence or absence of M. spicatum were those that influence water quality factors known to impact M. spicatum growth, rather than factors associated with human activity and dispersal potential. In particular, the amount of forest cover in the lake watershed was consistently important and could control the level of dissolved inorganic carbon in lakes, one of the factors known to affect M. spicatum growth rates. Factors such as the number of game fish species and number and types of boat ramps or proximity to roads were generally less important lake characteristics. Our models can be useful tools for developing management strategies to prevent or slow the spread of M. spicatum and aquatic invaders, such as the zebra mussel, that can attach to it and thus be dispersed. Our models also exemplify a general approach for slowing or stopping the spread of other invading species.
Impact of Data Availability on Site Assessment and Predictive Behavior of Aquatic Invasive Species
PURPOSE: The purpose of this study was to determine the status of available documentation of the physiological ecology of several invasive aquatic species in relation to the ability to predict which sites will be susceptible to invasion. INTRODUCTION: As of 2001, it was estimated that approximately 50,000 nonindigenous species had been introduced into the United States (Pimentel et al. 2000). Some are beneficial, including food crops (e.g. corn, wheat), livestock (e.g. cattle, sheep), landscape enhancement (e.g. crape myrtles, boxwoods), or biological pest controls (e.g. host-specific biological control insects and pathogens). Others, however, have caused major economic losses and harmful impacts to the envi-ronment. Over the past 40 years, introductions have increased because of human population growth and mobility and increased trade among nations (Pimentel et al. 2000). Fundamental to establishment success for any invasive species is a source of food and a place to live and repro...
Management of Biological Invasions, 2017
A thorough assessment of aquatic nonindigenous species' risk facilitates successful monitoring and prevention activities. However, species-and vector-specific information is often limited and difficult to synthesize across a single risk framework. To address this need, we developed an assessment framework capable of estimating the potential for introduction, establishment, and impact by aquatic nonindigenous species from diverse spatial origins and taxonomic classification, in novel environments. Our model builds on previous approaches, while taking on a new perspective for evaluation across species, vectors and stages to overcome the limitations imposed by single species and single vector assessments. We applied this globally-relevant framework to the Laurentian Great Lakes to determine its ability to evaluate risk across multiple taxa and vectors. This case study included 67 aquatic species, identified as "watchlist species" in NOAA's Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS). Vectors included shipping, hitchhiking/fouling, unauthorized intentional release, escape from recreational or commercial culture, and natural dispersal. We identified potential invaders from every continent but Africa and Antarctica. Of the 67 species, more than a fifth (21%) had a high potential for introduction and greater than 60% had a moderate potential for introduction. Shipping (72%) was the most common potential vector of introduction, followed by unauthorized intentional release (25%), hitchhiking/fouling (21%), dispersal (19%), stocking/planting/escape from recreational culture (13%), and escape from commercial culture. The ability to assess a variety of aquatic nonindigenous species from an array of potential vectors using a consistent methodology is essential for comparing likelihoods of introduction, establishment, and impact. The straightforward design of this framework will allow its application and modification according to policy priorities by natural resource managers. The ability to use a variety of information sources facilitates completion of assessments despite the paucity of data that often plagues aquatic nonindigenous species management.
Biological Invasions, 2011
Submersed aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects on the hydrological regime, sedimentation, nutrient cycling and habitat of associated fauna. Modifications of aquatic plant communities, for example through the introduction of invasive species, can alter these functions. In the Sacramento-San Joaquin River Delta, California, a major invasive submersed plant, Brazilian waterweed Egeria densa, has become widespread and greatly affected the functionality of the submersed aquatic plant community. Rapid assessments of the distribution and abundance of this species are therefore crucial to direct management actions early in the season. Given the E. densa bimodal growth pattern (late spring and fall growth peaks), summer assessments of this species may indicate which and where other submersed species may occur and fall assessments may indicate where this and other species may occur in the following spring, primarily because the Delta's winter water temperatures are usually insufficient to kill submersed aquatic plant species. We assessed community composition and distribution in the fall of 2007 and summer of 2008 using geostatistical analysis; and measured summer biomass, temperature, pH, salinity, and turbidity. In the fall of 2007, submersed aquatic plants covered a much higher proportion of the waterways (60.7%) than in the summer of 2008 (37.4%), with a significant overlap between the seasonal distribution of native and nonnative species. Most patches were monospecific, and multispecies patches had significantly higher dominance by E. densa, co-occurring especially with Ceratophyllum demersum. As species richness of non-natives increased there was a significant decrease in richness of natives, and of native biomass. Sustained E. densa summer biomass negatively affected the likelihood of presence of Myriophyllum spicatum, Potamogeton crispus, and Elodea canadensis but not their biomass within patches. Depth, temperature and salinity were associated with biomass; however, the direction of the effect was species specific. Our results suggest that despite native and invasive non-native submersed plant species sharing available niches in the Delta, E. densa affects aquatic plant community structure and composition by facilitating persistence of some species and reducing the likelihood of establishment of other species. Successful management of this species may therefore facilitate shifts in existing non-native or native plant species.
Backcasting and forecasting biological invasions of inland lakes
Ecological …, 2004
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 for Bythotrephes longimanus, a crustacean waterflea from Eurasia that is rapidly invading lakes in Ontario, Canada. The gravity model predicted spread of Bythotrephes based 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 (Ͼ100 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 of Bythotrephes is expected to expand to eastern and northwestern Ontario, although most new invasions are expected to occur in the central region of the province.
The introduction and spread of aquatic invasive species constitutes a global epidemic that continues to homogenize the world's aquatic flora and fauna. Species invasions are occurring at an unprecedented scale, yet few centrally organized distributional databases can accurately display location information used to prioritize management efforts within a watershed, region, or political boundary. For particularly harmful groups of invaders such as some freshwater invertebrates, one consequence is that predictive power is limited because current invasion patterns are unknown. We used the Nonindigenous Aquatic Species database of the US Geological Survey to determine current hotspots of invertebrate invasion in the US and compared those patterns with betterdocumented fish invasions. Invasive freshwater invertebrates were densely clustered in the Laurentian Great Lakes region compared to invasive fish that were concentrated in Florida and the Southwest.