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Todd B. Steeves

Publications and source records attributed to Todd B. Steeves.

13 recordsLinked to original sources

Ten lessons for controlling invasive species: Wisdom from the long-standing sea lamprey control program on the Laurentian Great Lakes

Sea lamprey ( Petromyzon marinus ) control in the Laurentian Great Lakes of North America is among the largest and most successful control programs of an invasive species anywhere on the planet. The effort began more than 75 years ago; it unites multiple nations, states, and provinces with the common goal of controlling this invasive species and protecting a valuable fishery. The science-based control program is administered by the Great Lakes Fishery Commission (GLFC), a body arising from a treaty signed by the United States and Canada. In the present article, we share 10 lessons learned from decades of successful sea lamprey control with the hopes of informing ongoing and future control programs targeting biological invasions. The 10 lessons we identified are to act boldly in times of crisis, to maintain the social license, to invest in capacity building, to break down the silos, to support fundamental science, to diversify your portfolio of control measures, to strive for continuous improvement, to confront the trade-off between information and action, to keep your foot on the gas, and to keep your eyes on the prize. The GLFC has long fostered a framework that uses some military strategy and verbiage that extends across the lessons (e.g., know your enemy). Other lessons are more nascent as the GLFC reenvisions its relationship with Indigenous peoples and governments in a path to reconciliation where two-eyed seeing is being embraced. Through adaptive management, horizon scanning methods, and embracing implementation science, the lessons learned about sea lamprey control will continue to evolve, which is itself a lesson. We submit that the lessons shared in the present article will help guide invasive species control programs spanning taxa, ecosystems, and regions.

Laurentian Great Lakes

Estimating age and growth of invasive sea lamprey: A review of approaches and investigation of a new method

We review recent advances in age and growth estimation of invasive sea lamprey ( Petromyzon marinus ) in the Great Lakes and present a more accurate method for growth estimation. To forecast growth and prioritize streams for control actions, sea lamprey managers currently use an average daily growth model. Here, a new linear model that included stream and lake as contributing variables was investigated and found to outperform the currently used growth model (roughly a 10 mm difference at age 1). Length-at-age of larvae between ages 1 and 4 were also best forecasted by a linear model with the predictor variables including growing degree days, stream, lake, and larval lamprey density. The model predicts that larval sea lamprey grow faster in warm streams with low densities of lamprey larvae. More accurate growth models could allow sea lamprey control managers to improve decisions concerning how sea lamprey control effort is allocated among streams, and could help inform broader modeling efforts evaluating the population demographics of a lake-wide populations exposed to varying control and environmental scenarios. Priority areas for research include investigating if temperatures have increased in sea lamprey-producing streams in response to climate change, using close-kin mark-recapture to mark family groups at age 1 to age large larvae and transformers years later, and determining if sex determination is environmentally mediated by larval growth and density.

Great Lakes

Trade-offs between suppression and eradication of sea lampreys from the Great Lake

Ecosystem managers confronted with newly invasive species may respond with a program of suppression or eradication. Suppression of an invasive species refers to management of a species such that its effect on other biota in the local ecosystem is acceptable. Eradication is the removal of all individuals of a species from a defined region. We examine the cost and benefit trade-offs between suppression and eradication of Laurentian Great Lakes sea lampreys ( Petromyzon marinus ) based on discussions at the 3rd Sea Lamprey International Symposium (held in 2019). Substantial effort has been expended annually since the 1960s to suppress sea lampreys in the Great Lakes basin. Choosing between suppression and eradication is a value judgement, ideally made jointly by scientists, decision-makers, stakeholders, and society. Successful large-scale eradications have been limited to a small number of cases for which the cost to human society justified and supported the long-term commitment necessary for success. The greatest challenge to successful eradication of sea lampreys from the Great Lakes may be a suitable social, political, legal, and institutional environment. Preparations could be made now for a transition in which public pushback on current control methods (pesticide applications and barriers to fish passage) leads to more extensive use of an alternative control method, such as genetic control.

Great Lakes and Saint Lawrence River areas

Lampricide bioavailability and toxicity to invasive sea lamprey and non-target fishes: The importance of alkalinity, pH, and the gill microenvironment

The lampricides TFM and niclosamide are added to streams to control invasive larval sea lamprey ( Petromyzon marinus ) populations in the Laurentian Great Lakes. Lampricide effectiveness depends upon TFM and niclosamide bioavailability which is influenced by both abiotic and biotic factors. For example, at lower pH, TFM bioavailability is higher because a greater proportion exists as un-ionized TFM (TFM-OH), which easily crosses the gills. At higher pH, however, the negatively charged ionized species of TFM (TFM-O − ) predominates, which is less easily taken-up, meaning more TFM must be applied. Although water alkalinity does not directly affect TFM speciation, as a buffer it influences how much expired water crossing the gills is acidified by CO 2 and metabolic acid excretion. In poorly buffered waters, greater acidification of the expired water increases TFM bioavailability in the gill microenvironment than in better buffered, higher alkalinity waters where more TFM must be applied. Hence, sea lamprey and non-target fishes such as lake sturgeon ( Acipenser fulvescens ) are more sensitive to lampricides in low pH, low alkalinity waters. Differences in gill structure and microenvironment acidification might also explain why TFM sensitivity of young-of-the-year lake sturgeon approaches or exceeds that of sea lamprey in higher alkalinity waters. Other biotic factors such as body size and metabolic rate also contribute to differences in lampricide sensitivity. We conclude that better understanding of the abiotic and biotic factors influencing lampricide bioavailability can be used to refine treatment protocols to improve lampricide effectiveness and to better protect non-target fishes from lampricide toxicity.

Journal of Great Lakes Research

Foreword: Control and conservation of lampreys beyond 2020 - Proceedings from the 3rd Sea Lamprey International Symposium (SLIS III)

Introduction to the special issue on the 3rd Sea Lamprey International Symposium. The compiled papers in this special issue consist of a combination of syntheses requested in advance of the symposium and perspectives that emerged from the symposium break-out discussions. These written contributions address the symposium goals of updating our understanding of sea lamprey control and research on lampreys since SLIS II and of exploring new ideas and posing new methods for controlling sea lamprey in the Great Lakes and supporting conservation of lampreys in their native ranges.

Journal of Great Lakes Research

Stream characteristics associated with feeding type in silver( Ichthyomyzon unicuspis ) and northern brook ( I. fossor ) lampreys and tests for phenotypic plasticity

In most lamprey genera, “paired” species exist in which the larvae are morphologically indistinguishable but adult feeding type differs. The lack of diagnostic genetic differences in many pairs has led to suggestions that they constitute a single gene pool with environmentally influenced feeding types. To investigate whether stream characteristics are correlated with feeding type in the parasitic silver lamprey Ichthyomyzon unicuspis and nonparasitic northern brook lamprey I. fossor, eight variables (pH, alkalinity, conductivity, discharge, total dissolved solids, and density of larval sea lamprey Petromyzon marinus, Ichthyomyzon spp., and total larval density) were compared among eight streams with only silver lamprey, 10 with only northern brook lamprey, and 13 with both species, using classification tree analysis. The most parsimonious model had a 24% misclassification rate, with silver lamprey tending to inhabit streams with higher sea lamprey larval density and northern brook lamprey tending to inhabit streams with higher Ichthyomyzon larval density. We then conducted a pilot study investigating phenotypic plasticity in a lab-based common garden experiment and an in situ transplant experiment. These studies encountered myriad difficulties and were unable to demonstrate plasticity, but did identify challenges associated with culturing Ichthyomyzon larvae. Development of effective rearing procedures for Ichthyomyzon lampreys is essential for any future similar studies.

Great Lakes, Lake Champlain basin

Rapid evolution meets invasive species control: The potential for pesticide resistance in sea lamprey

Rapid evolution of pest, pathogen and wildlife populations can have undesirable effects; for example, when insects evolve resistance to pesticides or fishes evolve smaller body size in response to harvest. A destructive invasive species in the Laurentian Great Lakes, the sea lamprey (Petromyzon marinus) has been controlled with the pesticide 3-trifluoromethyl-4-nitrophenol (TFM) since the 1950s. We evaluated the likelihood of sea lamprey evolving resistance to TFM by (1) reviewing sea lamprey life history and control; (2) identifying physiological and behavioural resistance strategies; (3) estimating the strength of selection from TFM; (4) assessing the timeline for evolution; and (5) analyzing historical toxicity data for evidence of resistance. The number of sea lamprey generations exposed to TFM was within the range observed for fish populations where rapid evolution has occurred. Mortality from TFM was estimated as 82-90%, suggesting significant selective pressure. However, 57 years of toxicity data revealed no increase in lethal concentrations of TFM. Vigilance and the development of alternative controls are required to prevent this aquatic invasive species from evolving strategies to evade control.

Canadian Journal of Fisheries and Aquatic Sciences

Correlating sea lamprey density with environmental DNA detections in the lab

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

Management of Biological Invasions

In situ assessment of lampricide toxicity to age-0 lake sturgeon

The lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2′, 5-dichloro-4′-nitrosalicylanilide (niclosamide) are used to control sea lamprey ( Petromyzon marinus ), an invasive species in the Great Lakes. Age-0 lake sturgeon ( Acipenser fulvescens ), a species of conservationconcern, share similar stream habitats with larval sea lampreys and these streams can be targeted for lampricide applications on a 3- to 5-year cycle. Previous laboratory researchfound that lake sturgeon smaller than 100 mm could be susceptible to lampricide treatments. We conducted stream-side toxicity (bioassay) and in situ studies in conjunction with 10 lampricide applications in nine Great Lakes tributaries to determine whether sea lamprey treatments could result in in situ age-0 lake sturgeon mortality, and developed a logistic model to help predict lake sturgeon survival during future treatments. In the bioassays the observed concentrations where no lake sturgeon mortality occurred (no observable effect concentration, NOEC) were at or greater than the observed sea lamprey minimum lethal concentration (MLC or LC99) in 7 of 10 tests. We found that the mean in situ survival of age-0 lake sturgeon during 10 lampricide applications was 80%, with a range of 45–100% survival within streams. Modeling indicated that in age-0 lake sturgeon survival was negatively correlated with absolute TFM concentration and stream alkalinity, and positively correlated with stream pH and temperature. Overall survival was higher than expected based on previous research, and we expect that these data will help managers with decisions on the trade-offs between sea lamprey control and the effect on stream-specific populations of age-0 lake sturgeon.

Journal of Great Lakes Research

Population ecology of the sea lamprey ( Petromyzon marinus ) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range.

Reviews in Fish Biology and Fisheries

Survival and metamorphosis of low-density populations of larval sea lampreys (Petromyzon marinus) in streams following lampricide treatment

Sea lamprey Petromyzon marinus control in the Great Lakes primarily involves application of lampricides to streams where larval production occurs to kill larvae prior to their metamorphosing and entering the lakes as parasites (juveniles). Because lampricides are not 100% effective, larvae that survive treatment maymetamorphose before streams are again treated. Larvae that survive treatment have not beenwidely studied, so their dynamics are notwell understood.Wetagged and released larvae in six Great Lake tributaries following lampricide treatment and estimated vital demographic rates using multistate tag-recovery models. Model-averaged larval survivals ranged from 56.8 to 57.6%. Model-averaged adult recovery rates, which were the product of juvenile survivals and adult capture probabilities, ranged from 6.8 to 9.3%. Using stochastic simulations, we estimated production of juvenile sea lampreys from a hypothetical population of treatment survivors under different growth conditions based on parameter estimates from this research. For fast-growing populations, juvenile production peaked 2 years after treatment. For slow-growing populations, juvenile production was approximately one-third that of fast-growing populations,with production not peaking until 4 years after treatment. Our results suggest that dynamics (i.e., survival, metamorphosis) of residual larval populations are very similar to those of untreated larval populations. Consequently, residual populations do not necessarily warrant special consideration for the purpose of sea lamprey control and can be ranked for treatment along with other populations. Consecutive lampricide treatments, which are under evaluation by the sea lamprey control program, would bemost effective for reducing juvenile production in large, fast-growing populations.

Michigan, Ontario, Wisconsin

Selecting Great Lakes streams for lampricide treatment based on larval sea lamprey surveys

The Empiric Stream Treatment Ranking (ESTR) system is a data-driven, model-based, decision tool for selecting Great Lakes streams for treatment with lampricide, based on estimates from larval sea lamprey ( Petromyzon marinus ) surveys conducted throughout the basin. The 2000 ESTR system was described and applied to larval assessment surveys conducted from 1996 to 1999. A comparative analysis of stream survey and selection data was conducted and improvements to the stream selection process were recommended. Streams were selected for treatment based on treatment cost, predicted treatment effectiveness, and the projected number of juvenile sea lampreys produced. On average, lampricide treatments were applied annually to 49 streams with 1,075 ha of larval habitat, killing 15 million larval and 514,000 juvenile sea lampreys at a total cost of $5.3 million, and marginal and mean costs of $85 and $10 per juvenile killed. The numbers of juvenile sea lampreys killed for given treatment costs showed a pattern of diminishing returns with increasing investment. Of the streams selected for treatment, those with > 14 ha of larval habitat targeted 73% of the juvenile sea lampreys for 60% of the treatment cost. Suggested improvements to the ESTR system were to improve accuracy and precision of model estimates, account for uncertainty in estimates, include all potentially productive streams in the process (not just those surveyed in the current year), consider the value of all larvae killed during treatment (not just those predicted to metamorphose the following year), use lake-specific estimates of damage, and establish formal suppression targets.

Journal of Great Lakes Research

Optimizing larval assessment to support sea lamprey control in the Great Lakes

Elements of the larval sea lamprey ( Petromyzon marinus ) assessment program that most strongly influence the chemical treatment program were analyzed, including selection of streams for larval surveys, allocation of sampling effort among stream reaches, allocation of sampling effort among habitat types, estimation of daily growth rates, and estimation of metamorphosis rates, to determine how uncertainty in each element influenced the stream selection program. First, the stream selection model based on current larval assessment sampling protocol significantly underestimated transforming sea lam-prey abundance, transforming sea lampreys killed, and marginal costs per sea lamprey killed, compared to a protocol that included more years of data (especially for large streams). Second, larval density in streams varied significantly with Type-I habitat area, but not with total area or reach length. Third, the ratio of larval density between Type-I and Type-II habitat varied significantly among streams, and that the optimal allocation of sampling effort varied with the proportion of habitat types and variability of larval density within each habitat. Fourth, mean length varied significantly among streams and years. Last, size at metamorphosis varied more among years than within or among regions and that metamorphosis varied significantly among streams within regions. Study results indicate that: (1) the stream selection model should be used to identify streams with potentially high residual populations of larval sea lampreys; (2) larval sampling in Type-II habitat should be initiated in all streams by increasing sampling in Type-II habitat to 50% of the sampling effort in Type-I habitat; and (3) methods should be investigated to reduce uncertainty in estimates of sea lamprey production, with emphasis on those that reduce the uncertainty associated with larval length at the end of the growing season and those used to predict metamorphosis.

Journal of Great Lakes Research