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Multi-scale effects of behavioral movement deterrents on invasive carp metapopulations

Behavioral deterrents of among-pool movement represent a promising tool for controlling invasive fish populations. To date, much of the research in this area has been focused on the direct effectiveness of different methods of deterrence. However, the effect of these structures on populations in spatially complex habitats is unknown. We combine a metacommunity model with movement data of two invasive species (bighead carp and silver carp) in a large river to assess local and river-wide scale population outcomes of deterrent locations. We calculated (1) which potential deterrent locations are most effective at reducing the growth at the invasion front (2) the river-scale population effects at each location, and (3) what, if any, are the risks imposed by altering the current spatial dynamics. We found that the effects on the population dynamics at the invasion front varied with the location of deterrents, ranging from near zero to effects equal to the reduction in an individual’s movement across the deterrent. The river-scale population growth rate was slightly increased by all potential deterrent placements because the deterrents tended to concentrate more of the river-scale population into pools with the highest recruitment rates. The short-term, transient dynamics followed a strictly decreasing pattern after deterrent placement suggesting no additional short-term risk. These results suggest that deterrents can be an effective and low-risk intervention for the control of invasive carp, although the population level effect will depend on the interaction of the traits and behavior of the species with the physical character and spatial structure of the habitat.

Illinois

Applying metapopulation theory to conservation of migratory birds

Metapopulation theory has proven useful for understanding the population structure and dynamics of many species of conservation concern. The metapopulation concept has been applied almost exclusively to nonmigratory species, however, for which subpopulation demographic independence—a requirement for a classically defined metapopulation - is explicitly related to geographic distribution and dispersal probabilities. Defining the degree of demographic independence among subpopulations of migratory animals, and thus the applicability of metapopulation theory as a conceptual framework for understanding population dynamics, is much more difficult. Unlike nonmigratory species, subpopulations of migratory animals cannot be defined as synonymous with geographic areas. Groups of migratory birds that are geographically separate at one part of the annual cycle may occur together at others, but co-occurrence in time and space does not preclude the demographic independence of subpopulations. I suggest that metapopulation theory can be applied to migratory species but that understanding the degree of subpopulation independence may require information about both spatial distribution throughout the annual cycle and behavioral mechanisms that may lead to subpopulation demographic independence. The key for applying metapopulation theory to migratory animals lies in identifying demographically independent subpopulations, even as they move during the annual cycle and potentially co-occur with other subpopulations. Using examples of migratory bird species, I demonstrate that spatial and temporal modes of subpopulation independence can interact with behavioral mechanisms to create demographically independent subpopulations, including cases in which subpopulations are not spatially distinct in some parts of the annual cycle.

Conservation Biology

The ecology of extinctions in kelp forest communities

We recognize three levels of extinction–global, local, and ecological – and provide examples of each. The protection and recovery of sea otters (Enhydra lutris) has provided abundant evidence of the consequences of their local extinction from kelp forest communities in the North Pacifc Ocean. These consequences include release of benthic invertebrate populations from limitation by predation; deforestation of kelp beds due to increased grazing by herbivorous sea urchins, one of the otter's main prey; and various cascading effects resulting from the biological and physical importance of kelp in coastal ecosystems. These interactions probably were important agents of selection for certain species. Two other examples are discussed: Steller's sea cow (Hydrodamalis gigas), a case of global extinction, and spiny lobsters, a possible case of ecological extinction. We speculate that grazing by sea cows was an important disturbance to surface-canopy-forming kelps and other algae in the littoral zones, but also point out that any such interactions probably acted in concert with physical disturbances by ocean waves. The ecological and evolutionary importance of sea cow grazing probably will remain a matter of speculation and conjecture because the species is globally extinct. Predation by spiny lobsters limits a variety of littoral and sublittoral invertebrate populations, particularly mollusks In one remarkable example, the reduction or local extinction of spiny lobsters enabled predutory whelks to increase in size and abundance, ultimately resulting in a predutor-prey role reversal. From these and other case studies we can clued that (1) the extinction of consumers may have brad and sometimes unexpected influences on kelp forest ecosystems; (2) direct or indirect interactions with now-extinct species probably exerted important selective influences on many extant forms; (3) such ecological and evolutionary influences are best understood where local or ecological extinctions, followed by recoveries, have provided comparisons in space or time; and (4) because of various ecological and behavioral barriers, local extinctions and their ecological consequences may not be simply reversed by protecting or reintroducing depleted or locally extinct species.

Conservation Biology

Estimating offsets for avian displacement effects of anthropogenic impacts

Biodiversity offsetting, or compensatory mitigation, is increasingly being used in temperate grassland ecosystems to compensate for unavoidable environmental damage from anthropogenic developments such as transportation infrastructure, urbanization, and energy development. Pursuit of energy independence in the United States will expand domestic energy production. Concurrent with this increased growth is increased disruption to wildlife habitats, including avian displacement from suitable breeding habitat. Recent studies at energy-extraction and -generation facilities have provided evidence for behavioral avoidance and thus reduced use of habitat by breeding waterfowl and grassland birds in the vicinity of energy infrastructure. To quantify and compensate for this loss in value of avian breeding habitat, it is necessary to determine a biologically-based currency so that the sufficiency of offsets in terms of biological equivalent value can be obtained. We describe a method for quantifying the amount of habitat needed to provide equivalent biological value for avifauna displaced by energy and transportation infrastructure, based on the ability to define five metrics: impact distance, impact area, pre-impact density, percent displacement, and offset density. We calculate percent displacement values for breeding waterfowl and grassland birds and demonstrate the applicability of our avian-impact offset method using examples for wind and oil infrastructure. We also apply our method to an example in which the biological value of the offset habitat is similar to the impacted habitat, based on similarity in habitat type (e.g., native prairie), geographical location, land use, and landscape composition, as well as to an example in which the biological value of the offset habitat is dissimilar to the impacted habitat. We provide a worksheet that informs potential users how to apply our method to their specific developments and a framework for developing decision-support tools aimed at achieving landscape-level conservation goals.

Ecological Applications

Neuroendocrine and behavioral implications of endocrine disrupting chemicals in quail

Studies in our laboratory have focused on endocrine, neuroendocrine, and behavioral components of reproduction in the Japanese quail. These studies considered various stages in the life cycle, including embryonic development, sexual maturation, adult reproductive function, and aging. A major focus of our research has been the role of neuroendocrine systems that appear to synchronize both endocrine and behavioral responses. These studies provide the basis for our more recent research on the impact of endocrine disrupting chemicals (EDCs) on reproductive function in the Japanese quail. These endocrine active chemicals include pesticides, herbicides, industrial products, and plant phytoestrogens. Many of these chemicals appear to mimic vertebrate steroids, often by interacting with steroid receptors. However, most EDCs have relatively weak biological activity compared to native steroid hormones. Therefore, it becomes important to understand the mode and mechanism of action of classes of these chemicals and sensitive stages in the life history of various species. Precocial birds, such as the Japanese quail, are likely to be sensitive to EDC effects during embryonic development, because sexual differentiation occurs during this period. Accordingly, adult quail may be less impacted by EDC exposure. Because there are a great many data available on normal development and reproductive function in this species, the Japanese quail provides an excellent model for examining the effects of EDCs. Thus, we have begun studies using a Japanese quail model system to study the effects of EDCs on reproductive endocrine and behavioral responses. In this review, we have two goals: first, to provide a summary of reproductive development and sexual differentiation in intact Japanese quail embryos, including ontogenetic patterns in steroid hormones in the embryonic and maturing quail. Second, we discuss some recent data from experiments in our laboratory in which EDCs have been tested in Japanese quail. The Japanese quail provides an excellent avian model for testing EDCs because this species has well-characterized reproductive endocrine and behavioral responses. Considerable research has been conducted in quail in which the effects of embryonic steroid exposure have been studied relative to reproductive behavior. Moreover, developmental processes have been studied extensively and include investigations of the reproductive axis, thyroid system, and stress and immune responses. We have conducted a number of studies, which have considered long-term neuroendocrine consequences as well as behavioral responses to steroids. Some of these studies have specifically tested the effects of embryonic steroid exposure on later reproductive function in a multigenerational context. A multigenerational exposure provides a basis for understanding potential exposure scenarios in the field. In addition, potential routes of exposure to EDCs for avian species are being considered, as well as differential effects due to stage of the life cycle at exposure to an EDC. The studies in our laboratory have used both diet and egg injection as modes of exposure for Japanese quail. In this way, birds were exposed to a specific dose of an EDC at a selected stage in development by injection. Alternatively, dietary exposure appears to be a primary route of exposure; therefore experimental exposure through the diet mimics potential field situations. Thus, experiments should consider a number of aspects of exposure when attempting to replicate field exposures to EDCs.

Hormones and Behavior

The relationship between female brooding and male nestling provisioning: does climate underlie geographic variation in sex roles?

Comparative studies of populations occupying different environments can provide insights into the ecological conditions affecting differences in parental strategies, including the relative contributions of males and females. Male and female parental strategies reflect the interplay between ecological conditions, the contributions of the social mate, and the needs of offspring. Climate is expected to underlie geographic variation in incubation and brooding behavior, and can thereby affect both the absolute and relative contributions of each sex to other aspects of parental care such as offspring provisioning. However, geographic variation in brooding behavior has received much less attention than variation in incubation attentiveness or provisioning rates. We compared parental behavior during the nestling period in populations of orange-crowned warblers Oreothlypis celata near the northern (64°N) and southern (33°N) boundaries of the breeding range. In Alaska, we found that males were responsible for the majority of food delivery whereas the sexes contributed equally to provisioning in California. Higher male provisioning in Alaska appeared to facilitate a higher proportion of time females spent brooding the nestlings. Surprisingly, differences in brooding between populations could not be explained by variation in ambient temperature, which was similar between populations during the nestling period. While these results represent a single population contrast, they suggest additional hypotheses for the ecological correlates and evolutionary drivers of geographic variation in brooding behavior, and the factors that shape the contributions of each sex.

Journal of Avian Biology

Sediment transport in the San Francisco Bay Coastal System: An overview

The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m 3 /day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

California

Disease emergence in birds: Challenges for the twenty-first century

The paper by Hartup et al. (2001) on House Finch ( Carpodacus mexicanus ) conjunctivitis is an example of the rapid geographic spread that can result from disease emergence in naïve populations. That event was neither novel nor transient relative to its occurrence or effects. Disease emergence and reemergence are hallmarks of the latter part of the twentieth century (Center for Disease Control 1994, Levins et al. 1994, DaSilva and Laccarino 1999, Gratz 1999). Current examples involving domestic animals include the problems in Europe with bovine spongiform encephalopathy (BSE, or “mad cow disease”) (Brown 2001) and foot-and-mouth disease (FMD) (Kitching 1999). Human health has been affected by diseases caused by an array of viruses (Morse 1993, Nichol et al. 1993, Murphy and Nathanson 1994), bacteria (Dennis 1998, DaSilva and Laccarino 1999), rickettsia (Walker and Dumier 1996, Azad et al. 1997), protozoans (Tuerrant 1997, Saini et al. 2000), and metazoan parasites (Hildreth et al. 1991, Gubler 1998), as well as other causes. Acquired immune deficiency syndrome (AIDS) has received the most notoriety of those diseases (Hahn et al. 2000, Schwartlander et al. 2000). A similar pattern exists on a global scale for free-ranging wildlife populations (Table 1) (Friend 1994, 1995; Epstein et al. 1998, Daszak et al. 2000). However, in comparison to disease emergence affecting humans and domestic animals, response to emerging diseases of wildlife is generally superficial. We present concepts and data to support our contention that failure to adequately address disease emergence in free-ranging wildlife is resulting in a diminished capability to achieve and sustain desired geographic distributions and population abundance for species of wild birds, including some threatened and endangered avifauna. For clarity, we define disease and disease emergence in the context of our use of those terms because they are the focus of our comments. Disease is any departure from health (Guralnik 1982); that is, dysfunction contributing to physiological, physical, reproductive, behavioral, or other impairment that reduces the probability of survival of individuals. If enough individuals are affected, the collective effects can reduce the sustainability of the population. Although disease can result from exposure to a wide variety of physical, chemical, and biological agents and other conditions, we focus this paper on microbes and parasites and to overt mortality caused by them. Thus, disease effects presented only represent the proverbial “tip of the iceberg” relative to the challenges wild avifauna face from disease. Our perspective of disease emergence expands the earlier definitions of emerging diseases by others (Centers for Disease Control and Prevention 1994, Morse 1995) to include all species. Our comments are defined by the context of disease occurrences that have increased within the past three decades, or threaten to increase in the near future relative to populations affected, geographic distribution, or magnitude of effects.

The Auk

Evaluating slash piles as habitat for a threatened salamander

Background Amplified wildfire activity in forests of the western United States threatens biodiversity. Fuel treatments can reduce fire severity, modify fire behavior, and restore forest structure and composition, yet impacts of some treatments, including slash piling and burning, on wildlife have received little attention. Piling of residual woody material may create habitable microenvironments for species that require cool, moist microclimates for all biological and ecological functions. One such species, the Sacramento Mountain salamander ( Aneides hardii Taylor), a relictual, endemic salamander narrowly distributed in the mountains of south-central New Mexico, USA, has been found below constructed slash piles within its range, but the characteristics of occupied slash piles and the extent of their occupancy has not yet been quantified. We surveyed for Sacramento Mountain salamanders in slash piles and under logs (cover objects) adjacent to piles and within a surrounding survey plot, and related salamander occupancy to slash pile and cover object characteristics, soil moisture and temperature, and environmental setting. Results We found Sacramento Mountain salamanders in 50% of surveyed slash piles. About 90% of salamanders were found in piles that contained black plastic sheeting, which held accumulations of moist leaf litter and other forest debris. We found no differences in pile characteristics, soil variables, or environmental setting between piles occupied by salamanders and piles in which no salamanders were detected. Salamander density was highest in slash piles, ~ 10% lower under cover objects in the survey area, and ~ 23% lower under cover objects adjacent to slash piles. Conclusions Slash piles serve as habitat for Sacramento Mountain salamanders. Our results suggest that within our study area or similar environments within the species range, any comparable slash pile has the potential to be occupied by salamanders. Species and habitat conservation measures indicated by this study and the timing of historical detections into mid-October include constructing smaller, pyramidal piles that minimize log-on-log or log-ground contact, avoiding the inclusion of black plastic in piles, limiting residence time of piles on the landscape, and initiating pile burning in late October or early November, when most salamanders are likely to have retreated below the ground surface.

New Mexico

Quagga and zebra mussels: biology, impacts, and control

Quagga and Zebra Mussels: Biology, Impacts, and Control , Second Edition provides a broad view of the zebra/quagga mussel issue, offering a historic perspective and up-to-date information on mussel research. Comprising 48 chapters, this second edition includes reviews of mussel morphology, physiology, and behavior. It details mussel distribution and spread in Europe and across North America, and examines policy and regulatory responses, management strategies, and mitigation efforts. In addition, this book provides extensive coverage of the impact of invasive mussel species on freshwater ecosystems, including effects on water clarity, phytoplankton, water quality, food web changes, and consequences to other aquatic fauna. It also reviews and offers new insights on how zebra and quagga mussels respond and adapt to varying environmental conditions. This new edition includes seven video clips that complement chapter text and, through visual documentation, provide a greater understanding of mussel behavior and distribution.

Book

Integrated patterns of residence and movement create testable hypotheses about fish feeding migrations

Developing and testing alternate hypotheses about patterns, mechanisms, and consequences of movement in geographically-large, heterogeneous, natural systems can advance the scientific understanding of animal migration and benefit the conservation of most mobile species. Within organismal movement trajectories, different combinations of residence and movement are predicted from existing ecological theories (e.g. long distance migration, site fidelity, central place foraging, ideal free distribution, habitat shifts). However, testing these conceptually-based, spatially-explicit hypotheses about animal movement and migration in the field can be logistically challenging. Here our purpose is to introduce Resmo , a framework of metrics and analyses that integrate site-specific RESidence and across-site MOvements. We illustrate the ecological insights from this framework using the empirical example of coastal Striped Bass ( Morone saxatilis ) during their seasonal feeding migration. Our use of site-specific Resmo applied to empirical telemetry data enhanced the understanding of feeding behavior of migratory fish, suggested testable ecologically-meaningful hypotheses about foraging, and identified criteria on which to base the selection of future sampling locations. In summary, the Resmo approach provides a useful new direction for thinking about animal migration, animal movement, biological conservation, and future priorities for empirical field data collection related to understanding the distribution of mobile organisms.

Scientific Reports

Book review: Conservation, ecology, and management of catfish: The second international symposium

This is the second publication in a series published by the American Fisheries Society devoted to catfish research, biology, and management, which was organized as a symposium held in St. Louis Missouri, in 2010 and builds upon the first symposium that was held in Davenport, Iowa, in 1998 (Irwin et al. 1999). The organizations of the second symposium stated that this was to "serve as an addendum to Catfish 2000" and "to cover the four corners of catfish science: catfish biology, ecology, management, and conservation" (p. xi). The book meets this standard easily. With 64 pages organized into nine sections (plenary, catfishes as sport fish, non-game catfishes, nonnative catfishes, movement and habitat use, sampling and population assessment, age and growth, behavior, and future directions), this publication covers these four corners and more. Review info: Conservation, Ecology, and Management of Catfish: The Second International Symposium. Edited by P. H. Michaletz and V. H. Travnichek, 2011. ISBN: 978-1934874257, 800 pp.

Fisheries

Reptiles and amphibians

Summary – We reviewed all the peer-reviewed scientific publications we could find on the known and potential effects of wind farm development, operation, maintenance, and decommissioning on reptiles and amphibians (collectively herpetofauna) worldwide. Both groups are declining globally due to a multitude of threats including energy development. Effect studies were limited to the long-term research by the authors on Agassiz’s Desert Tortoise ecology and behavior at single operational wind farm in California, US and an analysis of the effects of wind farm installation on species richness of vertebrates including reptiles and amphibians in northwestern Portugal. Research on Agassiz’s Desert Tortoise found few demonstrable differences in biological parameters between populations in the wind farm and those in more natural habitats. High reproductive output is due to the regional climate and not to the presence or operation of the wind farm. Site operations have resulted in death and injury to a small number of adult tortoises and over the long-term tortoises now appear to avoid the areas of greatest turbine concentration. Research in Portugal using models and simulations based on empirical data show that vertebrate species richness (including herpetofauna) decreased by almost 20% after the installation of only two large monopole turbines per 250 x 250 m plot. Knowledge of the known responses of herpetofauna to various disturbances allows identification of potential impacts from construction material acquisition in offsite areas, mortality and stress due to impacts of roads and related infrastructure, destruction and modification of habitat, habitat fragmentation and barriers to gene flow, noise, vibration, electromagnetic field generation, heat from buried high voltage transmission lines, alteration of local and regional climate, predator attraction, and increased risk of fire. Research on herpetofauna lags far behind what is needed and, in particular, before-after-control-impact studies are critically needed to identify cause and effect relationships in order to develop effective mitigation strategies for any negative impacts.

Book chapter

Effects of telemetry collars on two free-roaming feral equid species

There are two species of free-roaming feral equids in North America: horses ( Equus caballus ) and donkeys or “burros” ( E . asinus ). Both species were introduced as domestic animals to North America in the early 1500s and currently inhabit rangelands across the western United States, Canada, and all continents except Antarctica. Despite their global distribution, little is known about their fine scale spatial ecology. Contemporary research tools to assess space use include global positioning system (GPS) tracking collars, but older models were problematic due to stiff collar belting causing poor fit. We tested modern designs of GPS collars on n = 105 horses and n = 60 burros for 4 years in five populations (3 horse, 2 burro) across the western United States, to assess whether collars posed welfare risks to horses or burros. We found no difference in survival of collared versus uncollared mares and jennies, and no difference in survival of their foals. In 4036 of 4307 observations for horses (93.7%) and 2115 of 2258 observations for burros (93.6%), collars were observed symmetrical, maintaining proper fit on the neck. Fur effects from collars (sweaty neck, indented fur, broken fur) were seen in 3% of horse observations and 25% of burro observations. Superficial effects (chafes and marks on skin surface) were seen in 2% of horse observations and 11% of burro observations; no severe effects from collars were seen. Body condition was not affected by collars; mean body condition of collared horses was 4.70 ± 0.54 (mean ± s.d) and 4.71 ± 0.65 for collared burros. Behavior results indicated minimal effects; collared horses stood slightly more than uncollared, and collared burros stood and foraged more in one population, but not in the other. For 6.3% of observations of horses and 6.4% of observations of burros, we found an effect of time wearing a collar on the cumulative sum of fur effects which increased over time (burros: r s = 0.87, P = <0.0001; horses: r s = 0.31, P = 0.002). Burros also showed an increase over time in the number of superficial effects, but horses did not. Collars occasionally moved into the wrong position, shifting forward over the ears; we observed this on 19 horses and 1 burro. Of those, most collars went over the ears in summer ( n = 12). All collars were equipped with a remote release mechanism as well as a timed-release mechanism for redundancy, thus removed when observed in wrong position to avoid rubbing or discomfort. Our finding of no consequential physical effects in 98% of horse observations, and 89% of burro observations suggests the consequences of collars on free-roaming equid welfare and survival is biologically insignificant, although collars should be monitored regularly and continue to be equipped with a remote release mechanism to remove a collar if needed. With frequent welfare-driven, visual monitoring, collaring of free-roaming equids can be a safe and useful tool to increase our understanding of their spatial ecology, demography, habitat use, behavior, and interactions with other wildlife.

Arizona, Utah, Wyoming

Uptake and distribution of organo-iodine in deep-sea corals

Understanding iodine concentration, transport, and bioavailability is essential in evaluating iodine's impact to the environment and its effectiveness as an environmental biogeotracer. While iodine and its radionuclides have proven to be important tracers in geologic and biologic studies, little is known about transport of this element to the deep sea and subsequent uptake in deep-sea coral habitats. Results presented here on deep-sea black coral iodine speciation and iodine isotope variability provides key information on iodine behavior in natural and anthropogenic environments, and its geochemical pathway in the Gulf of Mexico. Organo-iodine is the dominant iodine species in the black corals, demonstrating that binding of iodine to organic matter plays an important role in the transport and transfer of iodine to the deep-sea corals. The identification of growth bands captured in high-resolution scanning electron images (SEM) with synchronous peaks in iodine variability suggest that riverine delivery of terrestrial-derived organo-iodine is the most plausible explanation to account for annual periodicity in the deep-sea coral geochemistry. Whereas previous studies have suggested the presence of annual growth rings in deep-sea corals, this present study provides a mechanism to explain the formation of annual growth bands. Furthermore, deep-sea coral ages based on iodine peak counts agree well with those ages derived from radiocarbon ( 14 C) measurements. These results hold promise for developing chronologies independent of 14 C dating, which is an essential component in constraining reservoir ages and using radiocarbon as a tracer of ocean circulation. Furthermore, the presence of enriched 129 I/ 127 I ratios during the most recent period of skeleton growth is linked to nuclear weapons testing during the 1960s. The sensitivity of the coral skeleton to record changes in surface water 129 I composition provides further evidence that iodine composition and isotope variability captured in proteinaceous deep-sea corals is a promising geochronometer as well as an emerging tracer for continental material flux.

Journal of Environmental Radioactivity

Sex, season, and time of day interact to affect body temperatures of the Giant Gartersnake

1.We examined multiple hypotheses regarding differences in body temperatures of the Giant Gartersnake using temperature-sensitive radio telemetry and an information-theoretic analytical approach.2.Giant Gartersnakes selected body temperatures near 30 ??C, and males and females had similar body temperatures most of the year, except during the midsummer gestation period.3.Seasonal differences in the body temperatures of males and females may relate to both the costs associated with thermoregulatory behavior, such as predation, and the benefits associated with maintaining optimal body temperatures, such as successful incubation.

Journal of Thermal Biology

Potential changes to the biology and challenges to the management of invasive sea lamprey Petromyzon marinus in the Laurentian Great Lakes due to climate change

Control programs are implemented to mitigate the damage caused by invasive species worldwide. In the highly invaded Great Lakes, the climate is expected to become warmer with more extreme weather and variable precipitation, resulting in shorter iced‐over periods and variable tributary flows as well as changes to pH and river hydrology and hydrogeomorphology. We review how climate change influences physiology, behavior, and demography of a damaging invasive species, sea lamprey ( Petromyzon marinus ), in the Great Lakes, and the consequences for sea lamprey control efforts. Sea lamprey control relies on surveys to monitor abundance of larval sea lamprey in Great Lakes tributaries. The abundance of parasitic, juvenile sea lampreys in the lakes is calculated by surveying wounding rates on lake trout ( Salvelinus namaycush ), and trap surveys are used to enumerate adult spawning runs. Chemical control using lampricides (i.e., lamprey pesticides) to target larval sea lamprey and barriers to prevent adult lamprey from reaching spawning grounds are the most important tools used for sea lamprey population control. We describe how climate change could affect larval survival in rivers, growth and maturation in lakes, phenology and the spawning migration as adults return to rivers, and the overall abundance and distribution of sea lamprey in the Great Lakes. Our review suggests that Great Lakes sea lamprey may benefit from climate change with longer growing seasons, more rapid growth, and greater access to spawning habitat, but uncertainties remain about the future availability and suitability of larval habitats. Consideration of the biology of invasive species and adaptation of the timing, intensity, and frequency of control efforts is critical to the management of biological invasions in a changing world, such as sea lamprey in the Great Lakes.

Great Lakes

Diel patterns of pheromone release by male sea lamprey

Costs to producing sexual signals can create selective pressures on males to invest signaling effort in particular contexts. When the benefits of signaling vary consistently across time, males can optimize signal investment to specific temporal contexts using biological rhythms. Sea lamprey, Petromyzon marinus , have a semelparous life history, are primarily nocturnal, and rely on pheromone communication for reproduction; however, whether male investment in pheromone transport and release matches increases in spawning activity remains unknown. By measuring (1) 3keto-petromyzonol sulfate (3kPZS, a main pheromone component) and its biosynthetic precursor PZS in holding water and tissue samples at six points over the course of 24 hours and (2) 3kPZS release over the course of several days, we demonstrate that 3kPZS release exhibits a consistent diel pattern across several days with elevated pheromone release just prior to sunset and at night. Trends in hepatic concentrations and circulatory transport of PZS and 3kPZS were relatively consistent with patterns of 3kPZS release and suggest the possibility of direct upregulation in pheromone transport and release rather than observed release patterns being solely a byproduct of increased behavioral activity. Our results suggest males evolved a signaling strategy that synchronizes elevated pheromone release with nocturnal increases in sea lamprey behavior. This may be imperative to ensure that male signaling effort is not wasted in a species having a single, reproductive event.

Integrative and Comparative Biology