Aquatic Nuisance Species Research Articles

Presence of zooplankton, eggs, and resting stages in ballast water samples from the Laurentian Great Lakes

To minimize the introduction and spread of aquatic nuisance species, the United States Coast Guard (USCG) and the International Maritime Organization (IMO) regulate the allowed microbe, protist, and zooplankton densities present in ballast water discharged from commercial ships. However, the density of eggs and resting stages in ballast discharge are not routinely assessed when determining the effectiveness of ballast water treatment systems.While the density of eggs and resting stages found in residual sediment has been examined by various researchers, the density in ballast water uptake and discharge samples was previously unexamined. Untreated uptake and discharge ballast water samples from 2017, 2022, and 2023, collected on ships within the Laurentian Great Lakes from August through January, were analyzed for eggs and resting stages. The samples contained a total density of 325–140,859 eggs and resting stages per cubic meter. These results demonstrate that uncounted eggs and resting stages are present in ballast water, contributing to the risk of spreading aquatic nuisance species within the Great Lakes.

Toxicity of Carbon Dioxide to Freshwater Fishes: Implications for Aquatic Invasive Species Management.

Carbon dioxide (CO2 ) has been approved by the US Environmental Protection Agency as a new aquatic pesticide to control invasive Asian carps and other aquatic nuisance species in the United States. However, limited CO2 toxicity data could make it challenging for resource managers to characterize the potential risk to nontarget species during CO2 applications. The present study quantified the toxicity of CO2 to 2 native riverine fishes, bluegill (Lepomis macrochirus) and fathead minnow (Pimephales promelas), using 12-h continuous flow-through CO2 exposure at 5, 15, and 25 °C water temperatures. Resulting survival indicated that bluegill (median lethal concentration [LC50] range 91-140 mg/L CO2 ) were more sensitive to CO2 than fathead minnow (LC50 range 235-306 mg/L CO2 ) across all water temperatures. Bluegill were also more sensitive to CO2 at 5 °C (LC50 91 mg/L CO2 , 95% CI 85-96 mg/L CO2 ) than at 25 °C (LC50 140 mg/L CO2 , 95% CI 135-146 mg/L CO2 ). Fathead minnow showed an opposite response and were less sensitive at 5 °C (LC50 306 mg/L CO2 , 95% CI 286-327 mg/L CO2 ) relative to 25 °C (LC50 235 mg/L CO2 , 95% CI 224-246 mg/L CO2 ). Our results show that CO2 toxicity can differ by species and water temperature. Data from the present study may inform decisions related to the use of CO2 as a control tool. Environ Toxicol Chem 2020;39:2247-2255. Published 2020. This article is a U.S. government work and is in the public domain in the USA.

Aquatic invasive species rapid response planning partnerships in the Lake Champlain basin: Bridging international, political, social, and economic gaps

The Lake Champlain Basin is threatened by several non-native invasive plant and animal species. The U.S. states of Vermont and New York, and the province of Quebec, Canada share the Lake Champlain watershed. The three jurisdictions work together to protect their water resources and implement Opportunities for Action, a long-term watershed management plan for the Basin. Together they recognise the need to control the introduction, spread, and impact of non-native invasive species in order to preserve the biological and ecological integrity of the Lake Champlain ecosystem independent of political borders. The Lake Champlain Basin Program Aquatic Nuisance Species Subcommittee is developing an invasive species rapid response action plan that addresses invasive species control and spread prevention in the Basin. A rapid response is an effort to contain and control non-native invasive species introductions while they are localised in a short amount of time, such as weeks or months, before they become established and more expensive to manage. Lake managers, policy makers, scientists, academics, and representa- tives of local watershed organisations from the three jurisdictions have shared information and data to foster the development of a comprehensive plan. Gaps in interstate and inter-jurisdictional laws and policy have been identified by reviewing all necessary permits for aquatic invasive species control methods. Examining the interface of law, policy, and permits aids in identifying regulatory and policy inadequacies, and opportunities for corrective legislation. Partnering among diverse organisations has allowed strategic invasive species rapid response planning that builds on managers' and policy makers' concerns, provides options, fosters inter-jurisdictional cooperation, and considers social, economic, and political impacts of invasive species man- agement. The rapid response planning process identifies lead agencies from each of the three jurisdictions, recommends the formation of one governing body, and includes detailed steps of a rapid response process. The goal of the rapid response plan is to foster dialogue among permit applicants, scientists, and regulatory agencies, to ensure the fastest action possible. The Lake Champlain Basin invasive species rapid response planning process provides an applicable model for the United Nations Educa- tional Scientific Organisation Hydrology for the Environment, Life, and Policy (HELP) basins around the world.

Salvinia molesta D.S. Mitch.

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Toxicity of Aqueous Alkaline Solutions to New Zealand Mudsnails, Asian Clams, and Quagga Mussels

Abstract We modeled the toxicity response of three important aquatic nuisance species to alkaline solutions of pH 12 to explore the potential use of chemical treatments for decontaminating infested water distribution systems, tanks, and other facilities in confined freshwater environments. Groups of quagga mussels Dreissena bugensis, New Zealand mudsnails Potamopyrgus antipodarum, and Asian clams Corbicula fluminea were tested in temperatures from 19 to 22°C in aqueous solutions adjusted to pH 12 with NaOH. The predicted 99% lethal exposure time (LT99) for adult-sized quagga mussels and New Zealand mudsnails respectively was 31.3 and 35.1 h. Longer exposures were needed to kill adult-sized Asian clams (LT99 = 208.9 h). Because of the worldwide use of NaOH as an alkaline reagent in a variety of industrial and pesticide applications, and its ease of neutralization with CO2, elevating the pH of freshwater solutions with NaOH may be a practicable management tool to remove nuisance species in biofouled canals, pipes, hatchery tanks, and other confined structures.

The potential impact of aquatic nuisance species on recreational fishing in the Great Lakes and Upper Mississippi and Ohio River Basins

Concern over the potential transfer of aquatic nuisance species (ANS) between the Great Lakes basin and the Upper Mississippi River basin has motivated calls to re-establish hydrologic separation between the two basins. Accomplishing that goal would require significant expenditures to re-engineer waterways in the Chicago, IL area. These costs should be compared to the potential costs resulting from ANS transfer between the basin, a significant portion of which would be costs to recreational fisheries. In this study, a recreational behavior model is developed for sport anglers in an eight-state region. It models how angler behavior would change in response to potential changes in fishing quality resulting from ANS transfer. The model also calculates the potential loss in net economic value that anglers enjoy from the fishery. The model is estimated based on data on trips taken by anglers (travel cost data) and on angler statements about how they would respond to changes in fishing quality (contingent behavior data). The model shows that the benefit to recreational anglers from re-establishing hydrologic separation exceeds the costs only if the anticipated impacts of ANS transfer on sport fish catch rates are large and widespread.

Changes in sea lamprey size and fecundity through time in the Great Lakes

Sea lamprey (Petromyzon marinus) are an aquatic nuisance species that cause great harm to fishes in the Great Lakes. Control of sea lamprey is vital to protecting the Great Lakes fishery, and designing an effective control program depends on accurate knowledge of their demographics. This study compared historical and current data on female sea lamprey length, weight, fecundity, gonadosomatic index (GSI) and egg weight in the Great Lakes. Female sea lamprey captured in 2011 were compared with studies conducted in 1960 and 1981 on Lake Superior and in 1981 and 1999 on Lake Ontario, as well as available data from Lakes Huron, Michigan and Erie. In Lake Superior, mean length and weight of female sea lamprey increased by approximately 13% and 45%, respectively, while mean fecundity increased 17% and individual egg weights increased 43%. There was no difference in mean sea lamprey GSI in Lake Superior. In Lake Ontario, female sea lamprey length increased by 7%, but there were no differences in the other metrics. Across the Great Lakes, there was a general increase in fecundity from the period before the 1980s to more recent years. An increased population of larger parasitic sea lamprey will have higher feeding rates and thus a higher impact on commercially and ecologically important fishes. Managers may need to reconsider control targets and lampricide treatment frequency for lakes where sea lamprey growth and fecundity have increased.

Factors Affecting Stakeholders' Willingness to Pay to Prevent the Spread of Aquatic Nuisance Species

Physical separation of the Great Lakes and Mississippi River basins has been identified as the most effective method for preventing the transfer of aquatic nuisance species, particularly Asian carp, from the Mississippi River Basin to the Great Lakes. The U.S. Army Corps of Engineers selected Extension to conduct a study of a key stakeholder group, Great Lakes charter captains, as a first step in assessing public opinion on the issue. Results reveal that the charter captains overwhelmingly support basin separation. Expanded educational outreach related to aquatic nuisance species, basin separation, and so forth would improve the ability of clientele to make informed decisions regarding separation of the basins.

Aquatic Nuisance Species in the Great Lakes and Mississippi River Basin-A Risk Assessment in Support of GLMRIS.

The U.S. Army Corps of Engineers is conducting the Great Lakes and Mississippi River Interbasin Study to identify the highest risk aquatic nuisance species currently established in either the Mississippi River Basin or the Great Lakes Basin and prevent their movement into a new basin. The Great Lakes and Mississippi River Interbasin Study focuses specifically on aquatic nuisance species movement through the Chicago Area Waterway System, a multi-use waterway connecting the two basins. In support of Great Lakes and Mississippi River Interbasin Study, we conducted a qualitative risk assessment for 33 aquatic nuisance species over a 50-year period of analysis based on the probability of aquatic nuisance species establishing in a new basin and the environmental, economic, and sociopolitical consequences of their establishment. Probability of establishment and consequences of establishment were assigned qualitative ratings of high, medium, or low after considering the species' current location, mobility, habitat suitability, and impacts in previously invaded systems. The establishment and consequence ratings were then combined into an overall risk rating. Seven species were characterized as posing a medium risk and two species as posing a high risk to the Mississippi River Basin. Three species were characterized as posing a medium risk to the Great Lakes Basin, but no high-risk species were identified for this basin. Risk increased over time for some aquatic nuisance species based on the time frame in which these species were considered likely to establish in the new basin. Both species traits and the need to balance multiple uses of the Chicago Area Waterway System must be considered when identifying control measures to prevent aquatic nuisance species movement between the two basins.

A Fish of Weedy Waters: Golden Shiner Biology and Culture

AbstractThe golden shiner, Notemigonus crysoleucas, is a major bait and forage fish species in the USA. Farmers produce millions of golden shiners annually that are distributed live, many across state boundaries. Native over much of the eastern and central USA, this species is often present but rarely abundant in natural systems, as fish density is apparently controlled by predation rather than by food resources. Aquaculture of the golden shiner is a century‐old practice and culture methods have evolved over time, resulting in today's farm‐raised, certified specific pathogen– and aquatic nuisance species–free baitfish. Federal and state agencies and universities have a long history of developing culture methods and promoting baitfish culture to replace the indiscriminate and wasteful harvest of fish from natural waters. Despite advances in culture methods and the advantages of a farm‐raised species produced under controlled and biosecure conditions, golden shiner farming is only marginally profitable and remaining farmers survive on farm equity and increased market share from others exiting the business. Ironically, increasing regulations and restrictions leading to a reduction in the supply of farm‐raised baitfish could drive anglers back to harvesting bait from natural waters, the very concern that initiated government support for baitfish culture a century ago.

Towards minimizing transport of aquatic nuisance species in ballast water: Do organisms in different size classes respond uniformly to biocidal treatment?

To reduce the transport and delivery of aquatic nuisance species in ships’ ballast water and comply with standards for the number of living organisms that may be discharged, biocidal agents and processes, such as chemical dosing, have been repurposed to treat ballast water. We evaluated whether marine planktonic organisms—the typical targets of these biocides—respond in unison to simulated treatment. Organisms were concentrated from seawater, which was amended with dissolved and particulate matter and cultured microalgae, and then treated by chlorination, ultraviolet radiation, or deoxygenation. Living organisms in three size classes (≥50, ≥10 and <50, and <10 µm [represented by culturable, heterotrophic bacteria]) were counted prior to and periodically after treatment. Regardless of whether the differences in concentrations between the control and treatments were significant or insignificant, in general, organisms across the size classes reacted comparably to treatments, with some exceptions in the <10 µm size class. The parallel responses of organisms to treatment—if shown to generalize to other water conditions, assemblages of organisms, and scales of treatment—may justify using a single size class to predict the responses of organisms across the broad size spectra. Notably, because most ballast water management systems employ a filtration step to remove organisms ≥50 µm, if organisms in the ≥10 and <50 µm size class were assessed to determine a vessel’s compliance with the discharge standard, it would be imperative that any filters would be evaluated to ensure they were functioning properly and removed organisms as designed.

Environmental Reviews and Case Studies: Stopping the Asian Carp and Other Nuisance Species: Cost Projections for Separating the Great Lakes and Mississippi River Basins Using U.S. Army Corps of Engineers Inputs

The U.S. Army Corps of Engineers’ Great Lakes and Mississippi River Interbasin Study, released in 2014, evaluates strategies to lessen the risk of Asian carp and other aquatic nuisance species transferring between these ecosystems. Due to the voluminous nature of the report and manner in which the results are presented, however, many important questions remain difficult to answer, such as: How do the costs of the different strategies differ; and How would the costs be distributed across various stakeholders? To help evaluate the results, this article uses the study’s many estimates, considerations of net present value, and other tools to show how the costs of the alternatives differ over a 50-year time period. This information can help inform policymakers about the best way to move forward with a cost-effective strategy to deal with aquatic nuisance species.Environmental Practice 17: 291–301 (2015)

Quantifying the total wetted surface area of the world fleet: a first step in determining the potential extent of ships’ biofouling

Ships’ hulls can transport aquatic nuisance species, but there is little quantitative information about the magnitude of vessel biofouling on a global or regional scale. There does not exist a robust method to estimate the wetted surface area (WSA) of a particular fleet of ships, especially across the diversity of possible vessel types. An estimate of the total WSA of ship arrivals into a port or region is essential to determine the potential scope of biofouling and to inform management strategies to reduce the future invasions. Multiple statistical models were developed so commonly available ships’ parameters could be used to estimate the WSA for a given set of fleet data. Using individual ship characteristics and publicly available data from ~120,000 active commercial ships in the world fleet, the method results in a total global minimum WSA estimate of approximately 325 × 106 m2. The size of the global fleet employed here is greater than the commonly cited vessel number of approximately 80,000–90,000, as we include ships <100 gross tons. Over 190,000 vessels were initially identified, representing a WSA of 571 × 106 m2, but active status of only 120,000 vessels could be confirmed. Reliable data were unavailable on the operating status of many additional and especially smaller vessels. This approach, along with a contemporary and comprehensive estimate of global WSA, when combined with knowledge of the different operational profiles of ships that may reduce biofouling (port residence times, steaming speeds, extent of antifouling coatings, cleaning frequency, etc.), can inform current numerical models and risk assessments of bioinvasions.

The Great Lakes Charter Fishing Industry: 2002 to 2011

We compare results of Great Lakes charter captain surveys from 2002 and 2011. Charter trips declined 27%, from over 103,000 in 2002 to less than 76,000 in 2011. Revenues between the two years fell 24%, from US$48.0 million to $36.4 million, after values were adjusted for inflation. An estimated 1,696 captains operated as small businesses in 2011: a decrease of over 12% from 2002. Fuel costs and age of the average charter vessel were significantly higher in 2011. Motivations for chartering were basically unchanged since 2002, and fishing continued to be a secondary income source for most captains. The economy and aquatic nuisance species were included among top concerns for the future of the industry in both years. Although the basic nature of the charter industry had not changed, captains were making management decisions to reduce costs and maintain the viability of their business.

Direct observations of fish incapacitation rates at a large electrical fish barrier in the Chicago Sanitary and Ship Canal

The electric barrier system in the Chicago Sanitary and Ship Canal was designed to eliminate interbasin transfer of aquatic nuisance species between the Mississippi River and Great Lakes Basins. Electrical output was recently increased in an effort to more effectively eliminate the upstream migration of bighead carp (Hypophthalmichthys nobilis) and silver carp (Hypophthalmichthys molitrix). Using gizzard shad (Dorosoma cepedianum) as a surrogate species, we examined the effectiveness of the barrier at incapacitating fish by placing them in a non-conductive cage and transporting the fish through the barrier. This experiment was conducted before and after changes in operating parameters. Higher electrical output increased barrier effectiveness by decreasing the distance required to incapacitation. Overall, 97% and 100% of fish became incapacitated at the lower and higher electrical operating parameters, respectively. Fish were incapacitated the soonest during the winter and spring, which was likely influenced by the reduced movement activity in the cooler months and the larger fish available for testing later in the spring. Moreover, effectiveness was influenced by type of boat hull material used during testing. Fish that were transported through the barrier along an aluminum-hull boat were able to swim nearly twice the distance into the barrier as those transported with a fiberglass-hull boat during the summer. The delayed incapacitations along the aluminum boat were presumably due to distortion of the electrical field caused by the conductive hull. These results raise concerns regarding the effect that metal-hull barges might have on the effectiveness of the barrier during navigation.

Zebra Mussel Colonization of Construction Materials, and Effectiveness of a Foul Release Coating

We compared zebra mussel (Dreissena polymorpha) colonization of six commonly used construction materials (PVC, concrete, steel, galvanized steel, pressure-treated wood, aluminum) plus a native unionid mussel shell, and examined effectiveness of the Intersleek® 970 Fluoropolymer Foul Release Coating system applied to the six materials in limiting colonization by this aquatic nuisance species. Coated and uncoated substrates were deployed in Marion Reservoir, Kansas, from April 2011 to August 2012. Density of colonizing zebra mussels was evaluated in July and November 2011, and durability of the substrates was monitored until August 2012. Mussels differentially utilized materials, with eight of the 13 substrates being colonized. PVC was colonized more heavily than galvanized steel and all surfaces coated with foul release fluoropolymer, which were largely mussel-free. Coating eventually showed signs of pitting, but did not delaminate from the materials to which it was applied. These results suggest that use of particular materials and coatings may aid management of some zebra mussel infestations.

Blocking and guiding adult sea lamprey with pulsed direct current from vertical electrodes

Controlling the invasion front of aquatic nuisance species is of high importance to resource managers. We tested the hypothesis that adult sea lamprey (Petromyzon marinus), a destructive invasive species in the Laurentian Great Lakes, would exhibit behavioral avoidance to dual-frequency pulsed direct current generated by vertical electrodes and that the electric field would not injure or kill sea lamprey or non-target fish. Laboratory and in-stream experiments demonstrated that the electric field blocked sea lamprey migration and directed sea lamprey into traps. Rainbow trout (Oncorhynchus mykiss) and white sucker (Catostomus commersoni), species that migrate sympatrically with sea lamprey, avoided the electric field and had minimal injuries when subjected to it. Vertical electrodes are advantageous for fish guidance because (1) the electric field produced varies minimally with depth, (2) the electric field is not grounded, reducing power consumption to where portable and remote deployments powered by solar, wind, hydro, or a small generator are feasible, and (3) vertical electrodes can be quickly deployed without significant stream modification allowing rapid responses to new invasions. Similar dual-frequency pulsed direct current fields produced from vertical electrodes may be advantageous for blocking or trapping other invasive fish or for guiding valued fish around dams.

The influence of light, stream gradient, and iron on Didymosphenia geminata bloom development in the Black Hills, South Dakota

The aquatic nuisance species Didymosphenia geminata was first documented in Rapid Creek of South Dakota’s Black Hills during 2002. Since then, blooms have occurred primarily in a 39-km section of Rapid Creek while blooms were rarely observed in other Black Hills streams. In this study, we evaluated factors related to the presence and development of visible colonies of D. geminata in four streams of the Black Hills. At the watershed scale, stream gradient was negatively associated with the occurrence of D. geminata whereas stream width was positively related to D. geminata presence. At the stream scale, D. geminata coverage was inversely related to canopy coverage and iron concentration. At the local scale, shading by bridges virtually eliminated growth of D. geminata colonies under bridges. At all three scales, proxy measures of light such as stream width, canopy coverage, and bridge shading revealed that light availability was an important factor influencing the presence and coverage of D. geminata colonies. In general, streams that had relatively wide stream reaches (mean = 9.9 m), shallow gradients (mean = 0.22%), and little canopy cover (mean = 13%) were associated with D. geminata blooms. In addition, iron concentrations in streams with D. geminata colonies were lower than in streams without blooms.

Approaches for determining the effects of UV radiation on microorganisms in ballast water

To minimize the dispersal of aquatic nuisance species through shipping, ballast water can be treated to kill, remove, or inactivate organisms. Ultraviolet (UV) radiation is used in some ballast water management systems to address this goal. Because UV treatment renders cells nonviable (by sterilizing them, preventing reproduction) and does not necessarily kill organisms instantaneously, the efficacy of UV treatment has been verified historically by regrowth assays in which microorganisms are cultured (and thus, reproduce) under optimal growth conditions. Although regrowth assays are definitive, they are time consuming—lasting for days or weeks—and, importantly, are applicable only to organisms amenable to culturing. Furthermore, these estimates of cell concentrations are often accompanied by large error estimates. In this paper, several rapid alternatives to regrowth assays are described and evaluated. An ideal approach would shorten or simplify the analysis burden and, potentially, could be used for shipboard testing to determine compliance with national and international ballast water standards. Complicating this task is the requirement that compliance with the ballast water standards will be determined by quantifying the number of living organisms in ships’ ballast water, and while organisms may be living following UV treatment, they may not be viable (i.e., they may not reproduce). To address this dichotomy , alternatives to regrowth assays were categorized based upon the complexity of the analysis and the means used to determine the status of microorganisms (either as viable or living): 1. Instantaneous growth and cell replication, 2. Cell activity and metabolic rates, 3. Cell structural integrity, and 4. Biomolecule presence and status. With the suite of approaches currently available, it is not possible to determine the viability of organisms rapidly, that is, within minutes of collecting a ballast water sample. Measurements of the photosystem integrity via variable fluorescence and the presence of adenosine triphosphate (ATP) are currently the most promising for rapidly estimating concentrations of living cells in compliance testing of ballast water discharges; however, extensive validation is required to verify the applicability of these approaches for the complexity of real-world samples.

The effect of different nutrient concentrations on the growth rate and nitrogen storage of watercress (Nasturtium officinale R. Br.)

The mechanisms that allow broadly distributed aquatic plants to inhabit variable resource environments are unclear, yet understanding these mechanisms is important because broad environmental tolerance is often linked to invasiveness in terrestrial and aquatic plants. In an experimental stream, we examined the effects of different nutrient concentrations on the growth rate, biomass, and foliar nutrient concentrations of a cosmopolitan and potentially invasive aquatic plant, Nasturtium officinale (R. Br.). Nasturtium seedlings were grown under six nutrient treatment levels ranging from 0.64 μm N:0.09 μm P to 1531 μm N:204.13 μm P, for 8 weeks. Absolute and relative growth rates, and biomass of seedlings increased along a gradient of increasing nutrient concentrations but the effect of nutrient concentration was dependent on growing time. Seedling biomass varied among nutrient treatments in weeks 4 through 8 of the experiment, but did not differ in week 2. By week 8, the two highest nutrient treatments had greater biomass than the two lowest nutrient treatments. Foliar nitrogen concentration increased, whereas carbon concentration and C:N ratios decreased in response to increasing nutrients. Nasturtium grows slowly in nutrient-poor conditions but rapidly increases its growth, biomass accrual, and nitrogen storage as conditions become nutrient-rich. The response of Nasturtium to enhanced nutrient conditions may indicate how aquatic nuisance species successfully invade and dominate plant communities in streams, where resources often vary both temporally and spatially.