Conservation Science Webinar Series
The views, opinions, or positions expressed in this webinar series are those of the guest presenter and do not necessarily reflect the views, opinions, positions of the US Fish and Wildlife Service or NCTC.
Conservation Science Webinar Descriptions
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Presented by Dr. James Estes, Department of Ecology and Evolutionary Biology, UC Santa Cruz. February 1, 2012.
In this webinar, Dr. Estes will summarize our current understanding of how large apex consumers influence the structure and function of ecosystems and I will argue that the global decline of these animals has been one of human-kind’s most pervasive influences on biodiversity. Following a brief introduction to the relevant concepts, the body of the presentation will be divided into two parts. The first of these is an overview of the work that my colleagues and I have done on sea otters and kelp forest ecosystems in the North Pacific Ocean over the past 40 years. I will explain the critical role that sea otters play in maintaining kelp forests and describe some of what we have learned about the follow-on influence of this so called “trophic cascade” on other species and ecosystem processes. The second part of the talk will look more broadly toward other species of apex consumers and the manners in which they influence their associated ecosystems. We will see from this that the sea otter’s keystone role in kelp forest ecosystems is not unique—similar top-down influences on plant assemblages and strong effects on associated landscapes occur from the tropics to the poles, on land, in lakes and streams, and in the oceans. I will conclude the webinar with a brief discussion of the implications of these findings for the management and conservation of natural resources.
Presented by Roy C. Averill-Murray, Desert Tortoise Recovery Coordinator USFWS. March 19, 2013.
The Mojave desert tortoise (Gopherus agassizii) was listed as threatened under the US Endangered Species Act (ESA) due to local population declines and an array of threats. Challenges to recovering this species are not unique to the desert tortoise but include 1) incomplete understanding of threats most responsible for population declines, 2) insufficient information on effectiveness of management actions, and 3) intractability of addressing threats across a large range and multiple jurisdictions. These challenges require long-term conservation efforts to ensure species persistence, with or without the protections of the ESA, which makes the Mojave desert tortoise a conservation-reliant species. This recognition necessitates a more structured approach to recovery, applying principles of Strategic Habitat Conservation. The revised recovery plan includes explicit population objectives and outlines a decision support system (DSS) through which spatially-explicit models relate populations to limiting factors on which managers can target recovery actions and assess their effectiveness. The new recovery program also established cross-jurisdictional recovery implementation teams comprised of land and wildlife managers from federal, state, and local agencies, non-governmental stakeholders, and scientists to prioritize, coordinate, and track implementation of recovery actions based on the outputs of the DSS. Strategic Habitat Conservation will improve the Mojave desert tortoise recovery program by linking management actions to reductions in risk to the species, thereby fostering improved management; by encouraging decision-making based on transparent, systematic application of the best available science; by facilitating strategic allocation of limited management, research, and monitoring funds; and by increasing accountability through the documentation of progress toward implementation and population goals.
Presented by Dr. Gretchen LeBuhn, Department of Biology, San Francisco State University. August 21, 2013.
Recently there has been considerable concern about declines in bee communities in agricultural and natural habitats. The value of pollination to agriculture, provided primarily by bees, is > $200 billion/year in the United States, and in natural ecosystems it is thought to be even greater. However, until recently no monitoring program existed to accurately detect declines in abundance of insect pollinators; thus, it is difficult to quantify the status of bee communities or estimate the extent of declines. We used data from eleven multiyear studies of bee communities to devise a program to monitor pollinators at regional, national, or international scales. These studies used seven different methods for sampling bees and represented three different continents We estimated that a monitoring program with 200-250 sampling locations each sampled twice over 5 years would provide sufficient power to detect small (2-5%) annual declines in the number of species and in total abundance and would cost US $2,000,000. To detect declines as small as 1% annually over the same time interval would require >300 sampling locations. Given the role of pollinators in food security and ecosystem function, we recommend establishment of integrated regional and international monitoring programs to detect changes in pollinator communities.
Presented by Sam Finney, Assistant Project Leader, Carterville Fish and Wildlife Conservation Office, USFWS. December 12, 2012.
This webinar will be an overview and history of Asian carp and their management in the United States. From their introductions in the 1970's, 80's, and 90's, to their proliferation in Midwestern rivers today, Asian carp have become one of the most widely known invasive species in the eyes of the American public. The jumping behavior of the silver carp as well as the contentious and highly publicized issues in keeping these fish out of the Great Lakes has given them prominence for the media, scientists, and the public. Topics covered will include the history of the introductions, their life history and deleterious effects, and what is or can be done to control the species in the United States, with a particular focus on the magnitude of efforts that have been underway to keep the fish out if the Great Lakes.
Presented by Dr. Mark E. Hauber, Hunter College, City University of New York. November 18, 2014.
Translocations of small or threatened populations to larger or safer localities are the bread and butter of conservation efforts in many regions of the world, especially in insular nations. Translocations are often highly successful, establishing independent, distant, and protected populations to improve the prospects of species longevity. But translocations also carry potential costs, which may or may not supersede these benefits, especially when there is both connectivity and asymmetry between the source and the destination sites and populations. Here I review both the behavioral (song culture and species recognition) and the genetic (theoretical modelling based) evidence for the potential impact of translocation efforts in several contexts
inspired by my own work in New Zealand.
Presented by Dr. Michael Sawaya, NSERC Visiting Fellow, Parks Canada and Carnivore Research Ecologist, Sinopah Wildlife Research Associates. July 22, 2014.
Wildlife crossing structures are one solution to mitigating the fragmentation of wildlife populations caused by roads, but their ability to connect populations has only been superficially evaluated. We conducted a three-year investigation to determine how wildlife crossing structures provide demographic and genetic connectivity for grizzly bears (Ursus arctos) and black bears (U. americanus) in Banff National Park, Alberta. We compared genetic data collected with a barbed-wire hair sampling system at wildlife crossings with data collected from populations surrounding the Trans-Canada Highway. Our objectives were to: 1) determine the number of bears using crossing structures, 2) examine the spatial and temporal patterns of use, 3) estimate the proportions of bear populations using crossings, and 4) determine how the highway and crossings affect gene flow. We identified 15 grizzly (7 F, 8 M) and 17 black bears (8 F, 9 M) using crossings. Grizzlies showed strong preference for open crossing structure types (e.g., overpasses). Peak use for both bear species occurred in July when high rates of foraging activity coincide with mating season. We detected considerable proportions of grizzly (15.1% in 2006; 19.7% in 2008) and black bear (18.5% in 2006; 10.6% in 2008) populations using crossings. We found a genetic discontinuity at the highway in grizzly bears but not in black bears. Parentage analysis showed that 47% of black bears and 27% of grizzly bears that used crossings were breeders. We conclude that wildlife crossing structures provide demographic and genetic connectivity for two bear species across a major transcontinental transportation corridor.
Presented by Dr. Erik Beever, Northern Rocky Mountain Science Center, USGS. September 25, 2014.
Integration of conservation efforts across geographic, biological, and administrative boundaries is a major movement in natural-resource management. This style of management and problem-solving is increasingly relevant, because drivers of change such as climate shifts, fire, and invasive species increasingly transcend these multidimensional boundaries and pervade conservation efforts on individual sites. Although the benefits of broad-scale conservation are compelling, it represents a complex challenge, owing to uncertainties in scaling up information and concepts as well as in coordination that addresses a more-diverse set of issues, governance structures, and partners. I and other researchers sought to explore the particular successes and challenges of established broad-scale conservation programs, to provide direction for future research towards a larger goal of enhancing effectiveness of broad-scale conservation (e.g., the LCC system). Using 17 questions, we gathered information from representatives of a diverse set of 11 broad-scale conservation partnerships spanning 29 countries on three continents. Despite demonstrated successes of these organizations, we revealed specific challenges that can hinder long-term success of broad-scale conservation. Engaging stakeholders, developing conservation measures, and implementing adaptive management were dominant challenges. Although these challenges have been identified previously in isolation, we used our results to develop integrative research questions addressing each of these challenges to inform and support effectiveness of existing and emerging broad-scale conservation efforts. I will share a list of challenges and a list of benefits reported by those engaged in broad-scale management and conservation around the world, as well as results regarding individual parts of the conservation process.
Presented by: Dr. Diana Papoulias, Research Fish Biologist, Columbia Environmental Research Center (USGS). April 17, 2013.
During this webinar I will present a case study from research we conducted in Nebraska’s Rainwater Basin (RWB). The area has a high density of wetlands in the midst of intensive agriculture. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Our objective was to determine whether there was an association between the environmental presence of endocrine disrupting chemicals and biomarkers previously shown to result from exposure to such chemicals. Despite our finding of a number of gonadal abnormalities, data interpretation was hindered because of several factors. I will discuss the results of the study and gaps in our understanding of amphibian biology that make interpretation of field-collected specimens difficult.
Presented by John McCamman, CA Condor Coordinator, USFWS Pacific Southwest Region and Corey Mason, R3 Director, Texas Parks and Wildlife Department Wildlife Division. May 18, 2015.
This two-part webinar will be presented by John McCamman, California Condor Coordinator with the U.S. Fish and Wildlife Service’s Pacific Southwest Region and Corey Mason, Region 3 Director for the Texas Parks and Wildlife Department Wildlife Division. Part I will focus largely on the status of condor recovery in the face of the impacts of lead ammunition, the mechanisms identified by states to address the impacts, how those mechanisms are working and what questions remain. Part II will address one of those questions in the context of mourning doves, in particular the efficacy of non-lead ammunition. This study compared the use of lead and steel shot loads for harvesting Mourning Doves. The researchers compared mourning dove harvest metrics for 1 lead (Pb 71/2, 32 g) and 2 steel (Fe 7 and Fe 6, 28 g) 12-gauge ammunition types using a double-blind field test in central Texas, USA. There were no differences in the number of attempts, or number of shots fired among ammunition types. Hunters were unable to distinguish the ammunition type being used in the field, and we detected no relationship between ammunition type and level of hunter satisfaction. Field analyses detected no difference in doves bagged per shot, wounded per shot, bagged per hit, or wounded per hit among the 3 ammunition types. Necropsy analyses detected no difference in the proportion of birds with through-body strikes, mean penetration depth of through-body strikes, or mean embedded pellet depth among ammunition types.
Presented by Dr. Rebecca D. Klaper, School of Freshwater Sciences, University of Wisconsin-Milwaukee. April 12, 2015.
Contaminants of Emerging Concern (CECs), such as pharmaceuticals, personal care products, flame retardants, and plasticizers have been found in waterways around the globe. They have been detected in small streams and even now in the Great Lakes1 even though it was previously thought that many of these compounds were used in small quantities and would not be measureable. Comparatively little information is known about the impacts of these chemicals particularly at the small concentrations at which they are found. However pharmaceuticals in particular are of great concern as they are designed to have specific physiological impacts. Our own research has shown that compounds such as diabetes medications and psychopharmaceuticals may have an impact on fish in particular at the concentrations at which they are found in the environment even though these are well below human therapeutic levels of these compounds.2,3 Of particular interest are their impacts on behavior and reproduction which may have significant population-level impacts. These compounds are not found singly and therefore the impacts of mixtures is also of great concern as there may be synergistic impacts of chemicals especially those that have similar mechanisms of action. In fact when we investigated a plasticizer and herbicide that were implicated as potential endocrine disruptors, exposure to a mixture of these two compounds had more than an additive endocrine disrupting impact on male fish4. One of the major issues is the lack of an organized national agenda to determine the impacts of these chemicals. The larger environmental community has called for more support and identified specific areas that need to be better researched to inform the evaluation of these compounds. 5 This presentation will highlight the data available and the policy issues raised by this area of research.
Presented by: Dr. Joseph J. Nocera, Ontario Ministry of Natural Resources, Trent University. August 28, 2012.
Dr. Nocera will discuss his research on a 48-year-long (1944–1992) dietary record for the chimney swift, determined from a well-preserved deposit of guano and egested insect remains in Ontario (Canada). This unique archive of palaeo-environmental data reflecting past chimney swift diets revealed a steep rise in dichlorodiphenyltrichloroethane (DDT) and metabolites, which were correlated with a decrease in Coleoptera remains and an increase in Hemiptera remains, indicating a significant change in chimney swift prey. We argue that DDT applications decimated Coleoptera populations and dramatically altered insect community structure by the 1960s, triggering nutritional consequences for swifts and other aerial insectivores.
Presented by Jenny Ovenden, principal research scientist with the Queensland Government and adjunct associate professor at the University of Queensland, Australia. May 2012.
Presented by Lei Dai, Ph.D. Candidate in Ecological Systems Biology at MIT. January 21, 2014.
Tipping points marking population collapse and other critical transitions in natural systems (e.g. ecosystems, the climate) can be described by a fold bifurcation in the dynamics of the system. Theory predicts that the approach of bifurcations will result in an increasingly slow recovery from small perturbations, a phenomenon called critical slowing down. We demonstrated the direct observation of critical slowing down before population collapse using replicate laboratory populations of the budding yeast. We mapped the bifurcation diagram experimentally and found a significant increase in both the size and timescale of the fluctuations of population density near a fold bifurcation, in agreement with the theory. Furthermore, we connected yeast populations spatially to evaluate warning signals based on spatio-temporal fluctuations and to identify a novel warning indicator in space. We propose a generic indicator based on deterministic spatial patterns, “recovery length”. As the spatial counterpart of recovery time, recovery length is defined as the distance for connected populations to recover from perturbations in space (e.g. a region of poor quality). In our experiments, recovery length increased substantially before population collapse, suggesting that the spatial scale of recovery can provide a superior warning signal before tipping points in spatially extended systems.
Presented by Elizabeth Hunter, University of Georgia Warnell School of Forestry and Natural Resources. May 6 2014.
Loss of key plant-animal interactions due to extinctions of large herbivores has diminished ecosystem functioning nearly worldwide. Mitigating for the ecological consequences of large herbivore losses through the use of ecological replacements to fill extinct species’ niches and thereby replicate missing ecological functions has been proposed. I will present a case study on the experimental introduction of ecological replacement giant tortoises to Pinta Island in the Galápagos Archipelago where the native species of giant tortoise (Chelonoidis abingdonii), recently extinct, once functioned as the sole large-bodied herbivore on the island and provided such services as disturbance, seed dispersal, and herbivory. Tortoises with a phenotype (saddlebacked) close to that of the native species were better able to fill the open niche in terms of habitat use compared to tortoises with a more divergent phenotype (domed). Computer simulations suggest that a larger, reproductive population of saddlebacked tortoises could reduce the woody plant encroachment that currently threatens the semi-arid grassland ecosystem on the island. Deployment of ecological replacement giant tortoises may therefore be a viable approach for restoring other semi-arid ecosystems where a native herbivore that previously had strong interactions with the plant community has gone extinct.
Presented by Dr. Emma Rosi-Marshall, Aquatic Ecologist, Cary Institute of Ecosystem Studies. December 3, 2013.
Pharmaceutical and personal care products (PPCPs) are now known to be ubiquitous in surface waters throughout the world. Their presence in aquatic ecosystems is an emerging concern for aquatic ecologists and the public. I will discuss the extent to which these novel contaminants occur in surface waters and will discuss the range of compounds present from antibiotics to illicit drugs. I will discuss various scales of inquiry that can be employed to measure the effects of PPCPs on aquatic ecosystem structure and function. I will present recent studies from my laboratory in that illustrate the potential effects of pharmaceuticals on stream ecosystem processes. For example, recent data indicates that primary production and respiration of stream biofilms is sensitive to common PPCPs (caffeine, cimetidine, ciprofloxacin, diphenhydramine, metformin, ranitidine and a mixture of each). In addition, data demonstrate that the responses to PPCPs is variable across land use gradients with urban stream microbial function less sensitive to exposure to PPCPs than forested streams. New research also demonstrates that aquatic organisms may be developing resistance to these compounds and widespread occurrence of PPCPs may be leading to altered microbial communities with potential consequences for ecosystem function. Pharmaceuticals and personal care products represent a suite of compounds in aquatic ecosystems that may have ecological consequences and this talk will describe current research and highlight research gaps.
Presented by Dr. David Hooper, Professor of Biology at Western Washington University. 01/15/2013.
Human society has had a negative impact on genetic, species, and functional diversity in ecosystems worldwide. A key question arising at the time of the first Earth Summit in Rio, twenty years ago, was: how will this loss of biological diversity alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper? In the interim, a breadth of evidence has accumulated that addresses different aspects of this question. In particular, recent evidence suggests that changing biodiversity could rival climate change and pollution in their effects on both plant production and decomposition. On the other hand, evidence that changing species richness has strong effects on ecosystem services directly valued by human society is more mixed. Finally, scientists are still struggling to link the patterns measured in experiments that directly manipulate species richness with actual changes in biodiversity at local to regional scales. In this webinar, I will review the findings that have allowed scientists to provide answers to some of these questions, as well as the key questions that remain.
Presented by Dr. Steve Fain, Research Coordinator for the Genetics Section at the USFWS National Forensics Laboratory. September 19, 2012.
A scan of recent titles from the molecular systematics literature finds the species tree of bears to be a classic “cloud of gene histories” punctuated by rapid events of divergence. As a result, the phylogeny of bears has been complicated by cross species hybridization and the incomplete sorting of ancestral polymorphism. It should come as no surprise then that the topology of the phylogenetic species tree of brown bears and polar bears is not always in agreement with estimations drawn from individual gene trees – most prominently those based on mitochondrial DNA (mtDNA). Our results from nuclear DNA (nDNA) sequence comparisons of polar bears, brown bears and black bears disprove the viewpoint from phylogenetic assessments of mtDNA that polar bear and brown bear diverged just 160,000 years ago. Calibrations of our data with nDNA divergences between polar bear–panda and polar bear–spectacled bear indicate that polar bears and brown bears separated more than 0.6 million years ago. Polar bears are an ancient sister lineage to brown bears and, as a consequence, have lived through several previous warm interglacial phases. Threats to their survival unique to this current phase will also be discussed.
Presented by Dr. Emilie Snell-Rood, Assistant Professor Department of Ecology, Evolution and Behavior, University of Minnesota. July 23, 2015.
The ecological impacts of road salt have primarily been studied with respect to the negative effects of chloride in aquatic systems. However, sodium is an important micronutrient for the development and functioning of neural and muscle tissue and is known to affect the foraging behavior of both vertebrates and invertebrates. Here I discuss recent research from our lab using butterflies as a model to investigate the effects of roadside sodium. First, we show that some (but not all) roadside plants have elevated sodium -- for instance, roadside milkweed has 16-30 times more sodium than plants collected 500m away. Second, we reared monarchs on roadside and prairie-collected milkweed, and found sex-specific effects on the development of eyes and flight muscle. Finally, we reared cabbage white butterflies on an artificial diet that varied in sodium content, and found parallel effects on muscle and brain development. Rearing at very high sodium levels resulted in elevated mortality. These results suggest that in some cases, road salt runoff may have positive impacts on herbivore development. Given the importance of sodium in animal foraging behavior, these results also suggest that some animals may be attracted to roadsides because of elevated sodium availability. I will conclude by discussing a variety of open and pressing future directions investigating roadside nutrition and foraging behavior of pollinators more generally.
Presented by Noel Burkhead, Research Fish Biologist, USGS. May 7, 2013.
North America encompasses the most intensely studied non-tropical aquatic faunas in the world. Contemporary conservation assessments have found extraordinarily high imperilment levels in mussels, snails, crayfishes, and fishes. Modern extinction rates in North American freshwater fishes were recently reported to be two orders of magnitude greater than background rates, but this estimate appears low. Revaluation of modern extinction rates in mussels, snails, crayfishes, and freshwater fishes suggests that modern extinctions are actually five to six orders of magnitude greater than background rates. Because worldwide data on contemporary extinctions in aquatic biotas are limited, extinction rates of North American aquatic biotas are compared to those of vertebrates worldwide. Since more is known about freshwater fishes, a summary of ecological attributes is presented. The predominate pattern is that we are continuing to lose rare and localized species, which will likely continue into the near future.
Presented by Ed Bangs, Wolf Recovery Coordinator, U.S. Fish and Wildlife Service. June 2011.
Gray wolf (Canis lupus) populations were deliberately eliminated from the northern Rocky Mountains (NRM) of the United States by 1930. Naturally dispersing wolves from Canada first denned in Montana in 1986. In 1995 and 1996 wolves from western Canada were reintroduced to central Idaho and Yellowstone National Park to accelerate recovery. The population increased >20%/yr after 1995, but has stabilized since 2008. In December 2010, there were at least 1,650 wolves in 244 packs [115 successfully reproducing as breeding pairs]. In April 2011 another >600 pups were born. The NRM wolf population has very high genetic diversity and is connected to a large western Canada wolf population. A high level of effective migration was maintained by natural dispersal when <850 wolves were present. Wolves now occupy >110,000 square miles in the NRM and suitable habitat (largely forested mountainous public land) appears saturated with resident wolf packs. Wolf restoration initially proceeded with more benefits (public viewing and restoration of ecological processes in natural areas), and fewer problems (livestock and pet depredation, decreases in wild ungulate populations, and agency wolf control) than predicted. But problems eventually increased and reduced local tolerance of wolves. In 2011 Federal legislation enacted the USFWS's 2009 science-based delisting rule. Wolves are now managed just like other resident wildlife, except in Wyoming where wolves remained listed. While the NRM wolf population is certainly biologically viable, public opinion remains divisive and litigation continues on several issues. Some habitat suitable for persistent wolf packs exists outside of western Montana, central and northern Idaho, and northwestern Wyoming, but appears limited compared to the NRM because of potential conflicts with local residents.
Presented by Dr. Maureen Ryan, Department of Evolution and Ecology and Center for Population Biology, University of California, Davis. October 22, 2013.
Biological invasions and habitat alteration both create challenges for native species. In the intensively farmed Salinas Valley of California, threatened California tiger salamanders (Ambystoma californiense) have been replaced by hybrids between California tiger salamanders and introduced barred tiger salamanders (Ambystoma tigrinum mavortium, BTS) following the introduction of BTS in the 1950s and 1960s. Hybrids are known to outperform native salamanders in a variety of ecological traits such as size at metamorphosis, distance-walking ability, and predation. The unexpected results of a field experiment now show that hybrid salamanders are also better able to survive periods of poor water quality that caused die-offs of salamander larvae in ponds in the Salinas Valley. During die-offs, all native salamander larvae died, whereas 44% of hybrid larvae survived. Necropsy results, changes in the ponds' biological community, shifts in salamander sex ratio, and patterns of pesticide application in adjacent fields suggest that pesticide use may have contributed to the die-offs. The increased survival of hybrids through periods of environmental stress may contribute to the rapid displacement of native genotypes in regions undergoing human-induced change.
Presented by Dr. Mark Green, Assistant Professor of Hydrology, Center for the Environment, Plymouth State University. November 19 2013.
Acid deposition during the 20th century depleted base cations in the northeast United States and around the globe, substantially altering terrestrial ecosystem function. To understand ecological response to depleted calcium (Ca) soil concentrations, watershed 1 (W1) at the Hubbard Brook Experimental Forest was amended with enough Ca to bring soil Ca concentrations to pre-industrial levels. Following the amendment, the hydrology of W1 changed; annual evapotranspiration (ET; calculated as the difference between precipitation and runoff) increased by 25%, 18%, and 19% respectively for the three years following treatment, followed by a return to normal ET rates ever since. Concurrently, stream water chemistry changed, showing high Ca retention following the wollastonite addition. We hypothesize that trees in W1 responded to the Ca amendment through a few possible mechanisms that stimulated transpiration for the three years following treatment. Hydrologic change resulting from the Ca amendment suggests that historical and future changes to soil Ca concentrations may have concurrently altered or will alter water cycle dynamics.
Presented by Dr. David M. Cwiertny, Assistant Professor, Department of Civil and Environmental Engineering, University of Iowa. April 24, 2014.
Trenbolone acetate (TBA) is one of three synthetic hormones widely utilized as growth promoters in animal agriculture. It is estimated that between 10-25 million beef cattle in the United States are implanted with TBA annually, directly accounting for over $1 billion in value added to the meat production industry. With such high application rates, discharge into the environment is a near certainty. Nevertheless, despite reports that extended exposure to TBA metabolites can impact fish fecundity at nanogram per liter levels, relatively little is known about the fate of growth promoters in natural aquatic systems. Here, we report results of laboratory studies examining the persistence and fate of TBA and other FDA approved synthetic growth promoters (i.e., melengestrol acetate and zeranol) in natural aquatic and soil systems. The case of TBA metabolites proves most unique, with these species generally exhibiting high reactivity in sunlit surface waters where they rapidly undergo photolysis. We have discovered, however, that the primary photolysis pathway, so-called photohydration, is reversible at ambient environmental conditions. Thus, at nighttime (in the absence of sunlight), bioactive metabolites of TBA can be regenerated to appreciable levels via the decomposition of their primary photolysis products. Ultimately, this reversible photolysis reaction will lead to much greater persistence of TBA metabolites in surface waters than is currently realized. Because the use of such growth promoters is often predicated on their limited environmental persistence, this work has profound implications for the health and safety of ecosystems impacted by runoff from animal agricultural operations.
Presented by Dr. Sarah Knutie, University of South Florida. December 9, 2014.
Introduced parasites are a threat to biodiversity when naïve hosts lack effective defenses against such parasites. Several parasites have recently colonized the Galápagos Islands, threatening native bird populations. For example, the introduced parasitic nest fly Philornis downsi (Diptera: Muscidae) has been implicated in the decline of endangered species of Darwin’s finches, such as the mangrove finch (Camarhynchus heliobates). First, I will present data on the effect of P. downsi on Darwin’s finch nestling survival; nests directly fumigated with a mild insecticide (1% permethrin solution) had fewer parasites and fledged more offspring than nests treated with water. I will then show that Darwin’s finches can be encouraged to “self-fumigate” nests with cotton fibers that have been treated with a 1% permethrin solution. Nests with treated cotton had significantly fewer P. downsi than control nests, and nests containing at least one gram of treated cotton were virtually parasite-free. The results from this study demonstrate that self-fumigation can be used to mitigate the effect of nest flies on Darwin’s finches and potentially in other systems.
Presented by Dr. Jason Fridley, Associate Professor of Biology at Syracuse University. February 4, 2013.
Temperate deciduous forests of the Eastern U.S. are increasingly dominated by Eurasian shrubs and vines, many of which exhibit high shade tolerance and an ability to outcompete native tree seedlings and understory species. I describe a comparative case study of the growth behaviors of many of these invaders and their native relatives. Using several years of seasonal data on leaf production and photosynthesis in a common shade garden, I show that non-native invasive shrubs and vines extend the understory growing season by nearly a month compared to natives, revealing an 'autumn niche' that is nearly absent in our native shrubs. I then outline several other aspects of the biology of the invaders that suggest they are using alternative strategies of resource foraging, and explore the potential ecosystem impacts of these behaviors.
Presented by Dr. Collin Eagles-Smith, UGS. January 21, 2015.
Mercury (Hg) is a global contaminant and human activities have increased atmospheric Hg concentrations 3- to 5-fold during the past 150 years. This increased release into the atmosphere has resulted in elevated loadings to aquatic habitats where biogeochemical processes promote the microbial conversion of inorganic Hg to methylmercury, the bioavailable form of Hg. The physicochemical properties of Hg and its complex environmental cycle have resulted in some of the most remote and protected areas of the world becoming contaminated with Hg concentrations that threaten ecosystem
and human health. The national park network in the United States is comprised of some of the most pristine and sensitive wilderness in North America. There is concern that via global distribution, Hg contamination could threaten the ecological integrity of aquatic communities in the parks and the wildlife that depends on them. In this study, we examined Hg concentrations in non-migratory freshwater fish in 86 sites across 21 national parks in the Western United States. We report Hg concentrations of more than 1,400 fish collected in waters extending over a 4,000 kilometer distance, from Alaska to the arid Southwest. Across all parks, sites, and species, fish total Hg (THg) concentrations ranged from 9.9 to 1,109 nanograms per gram wet weight (ng/g ww) with a mean of 77.7 ng/g ww. We found substantial variation in fish THg concentrations among and within parks, suggesting that patterns of Hg risk are driven by processes occurring at a combination of scales. Additionally, variation (up to 20-fold) in site-specific fish THg concentrations within individual parks suggests that more intensive sampling in some parks will be required to effectively characterize Hg contamination in western national parks. Across all fish sampled, only 5 percent had THg concentrations exceeding a benchmark (200 ng/g ww) associated with toxic responses within the fish themselves. However, Hg concentrations in 35 percent of fish sampled were above a benchmark for risk to highly sensitive avian consumers (90 ng/g
ww), and THg concentrations in 68 percent of fish sampled were above exposure levels recommended by the Great Lakes Advisory Group (50 ng/g ww) for unlimited consumption by humans. Of the fish assessed for risk to human consumers (that is, species that are large enough to be consumed by recreational or subsistence anglers), only one individual fish from Yosemite National Park had a muscle Hg concentration exceeding the benchmark (950 ng/g ww) at which no human consumption is advised. Zion, Capital Reef, Wrangell-St. Elias, and Lake Clark National Parks all contained sites in which most fish exceeded benchmarks for the protection of human and wildlife health. This finding is particularly concerning in Zion and Capitol Reef National Parks because the fish from these parks were speckled dace, a small, invertebrate-feeding species, yet their Hg concentrations were as high or higher than those in the largest, long-lived predatory species, such as lake trout. Future targeted research and monitoring across park habitats would help identify patterns of Hg distribution across the landscape and facilitate management decisions aimed at reducing the ecological risk posed by Hg contamination in sensitive ecosystems protected by the National Park Service.
Presented by Christopher G. Guglielmo, Associate Professor, Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, November 2, 2011.
Both the flight and refueling phases are physiologically demanding for birds and bats. In this webinar I will discuss aspects of fuel and water metabolism and how environmental conditions experienced during either flight or refueling can affect migration performance. I will also discuss physiological approaches to assessing stopover habitat quality.
Presented by Paul DuBowy, Ph.D., Environmental Program Manager for the U.S. Army Corps of Engineers MS Valley Division, Vicksburg, MS, June 9, 2011.
The Mississippi River is one of the world's great rivers and is the only river in the United States to be formally recognized by Congress as both a nationally significant ecosystem and commercial navigation system. The river has a long and colorful history and has played a significant role in shaping the region's social and economic development. However, the Mississippi River is not a single homogeneous unit. From its source in northern Minnesota to the Gulf of Mexico one can identify at least five distinct Mississippi Rivers based on geomorphology and hydraulics. Concomitant with these hydrological differences in the river are variations in navigation and flood risk management that result in divergent river management strategies. Levees, wing dikes, floodways, dams, pools and locks are some of the different structures that are in place on various reaches of the river to address the concerns of flood risk management and navigation. The effects of river regulation, floodplain development and watershed modifications present constant challenges to ecosystem sustainability along the Mississippi River. Consequently, floodplain and wetland rehabilitation must be developed within the context of the extremely different directions that navigation and flood management have taken the river. Because the Mississippi system varies widely in hydraulics and hydrology from source to the Gulf, ecosystem rehabilitation likewise takes different forms in different regions along the river. Moreover, the goals, targets and metrics of ecosystem sustainability are not constant across the entire river system. A holistic view of the Mississippi River and its contributions to the economic and environmental health of the United States must be developed and implemented to insure the sustainability of this important ecosystem.
A debate between Dr. Mark Davis, DeWitt Wallace Professor of Biology, Macalester College and Dr. Daniel Simberloff, Gore Hunger professor, Environmental Studies, University of Tennessee-Knoxville.
Two of the leading scientists in the field of Invasion Biology, Dr. Mark Davis (author of the book Invasion Biology, published in 2009 by Oxford University Press) and Dr. Daniel Simberloff (Director of the Institute for Biological Invasions at the University of Tennessee-Knoxville) will discuss when, if and how conservation biologists and managers should deal with non-native species.
Presented by Dr. Gordon Holtgrieve and Dr. Daniel Schindler, University of Washington, and Patrick Walsh, Togiak National Wildlife Refuge. November 13, 2012.
The authors detected nitrogen derived from human activities in lakes throughout the Northern Hemisphere. The 36 study lakes occur in remote locations hundreds of miles from the nearest city, industrial area or farm, and include lakes on the Togiak National Wildlife Refuge in southwestern Alaska. The findings, recently published in the journal Science, are based on historical changes in the chemical composition of sediment deposits using an approach similar to aquatic archeology. More than three quarters of the lakes, ranging from the U.S. Rocky Mountains to northern Europe, showed a distinctive and coherent signal of nitrogen released from human activities since the Industrial Revolution.
Presented by Professor Laurel E. Phoenix, University of Michigan-Green Bay, August 11, 2011.
This webinar will investigate how urbanization, aging water infrastructure, peak energy, climate change, and increasing corporatization influence water quantity, distribution, and quality to challenge fish and wildlife conservation efforts?
Presented by David Manthos, Communications Director for SkyTruth, an environmental research organization using remote sensing and digital mapping to track and analyze the environmental impact of human activity and natural resource extraction around the world. November 4, 2015.
Hear how a West Virginia-based non-profit uses remote sensing and geospatial data to track global conservation issues – from fracking in Pennsylvania to illegal fishing on the far side of the world. SkyTruth is an environmental research organization using remote sensing and digital mapping to track and analyze the environmental impact of human activity and natural resource extraction around the world. Communications Director David Manthos will describe how SkyTruth grew from a single remote-sensing expert into a team of programmers and GIS analysts mapping the spread of mountaintop removal coal mining in Appalachia, recruiting citizen scientists to help map fracking in the mid-Atlantic, and building new tools to track commercial fishing in near real-time using satellite-derived vessel location data.
Presented by Dr. Jeffrey M. Lorch, Research Associate, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison. February 12, 2014.
Snake Fungal Disease (SFD) is an emerging disease in certain populations of wild snakes in the eastern United States. While fungal skin infections were occasionally reported in wild snakes prior to 2006, the number of free-ranging snakes with fungal dermatitis submitted to the USGS National Wildlife Health Center (NWHC) and other diagnostic laboratories has been increasing. Laboratory analyses have demonstrated that the fungus Ophidiomyces (formerly Chrysosporium) ophiodiicola is consistently associated with SFD, but definitive evidence that O. ophiodiicola causes SFD is lacking. While mortality has been associated with some cases of SFD, population-level impacts of the disease are not yet widely known and are difficult to assess due to the cryptic and solitary nature of snakes and a general lack of long-term monitoring data. This webinar will focus on the current state of knowledge of SFD, including a discussion of how to identify possible cases of the disease in field and what types of laboratory tests can be run to confirm SFD in an animal.
Presented by Dr. Tom McCarthy, Executive Director, December 13, 2011.
Snow leopards are one of the most mysterious yet iconic of the wild cats. Superbly adapted to thrive in some of the harshest conditions on the planet, they live and roam in solitude across the vast and rugged mountains ranges of central Asia. Seldom observed in the wild, this rare and secretive creature has long been poorly understood. For nearly two decades Dr. Tom McCarthy has traveled to some of the most remote corners of snow leopard range to study them, identify threats to their survival, and initiate conservation programs to protect them. In this webinar he will share the snow leopard’s story – from their ecology and life history, to their precarious existence in the face of widespread poaching, to optimism brought about by successful conservation efforts. He will also share highlights from South Gobi, Mongolia, where he now leads the first-ever long-term study of the species using GPS-satellite collars, remote camera traps and other cutting-edge research techniques.
Presented by Scott R. Loarie, Post Doctoral Fellow, Department of Global, Carnegie Institute for Science, Stanford, CA, July 19, 2011.
Social networks have revolutionized the way people share information across the internet. The volume of plant and animal photographs shared on sites like Facebook and Flickr has outpaced specimen collection efforts by mueums governments and academics. Yet this information has yet to be harnessed for science and conservation. iNaturalist.org, a social network for naturalist, aims to connect amateurs and experts to convert photos of biodiversity shared on the web into useful data for science and conservation. On May 25th, in partnership with the Smithsonian, IUCN/ssc, and others iNaturalist launched the Global Amphibian Bioblitz, an effort to cenusus every species of amphibian. In the first three weeks, the effort yielded over 400 distinct species from 36 countries representing 79% of the world's amphibian families and 83 threatened species. The effort peaked the interest of those interested in engaging the public about conservation as well as concern from groups combating collecting and poaching. The success of efforts like the Global Amphibian Bioblitz reveals the potential of citizen-science through social networks as a scalable and cost-effective new tool for monitoring global biodiversity.
Presented by Rusty Griffin, Physical Scientist with the National Wetland Inventory National Standard and Support Team, USFWS. March 11, 2014.
The U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration (NOAA) have analyzed the status and recent trends of wetland acreage in the coastal watersheds of the United States adjacent to the Atlantic Ocean, Gulf of Mexico, Great Lakes and the Pacific coastline of Washington, Oregon and California. Results indicate that coastal watersheds experienced a net loss in wetland area of about 80,160 acres per year from 2004 to 2009. This represents a 20,000 acre per year increase in the rate of wetland loss as reported by the Service and NOAA for the period between 1998 and 2004. The increase in the rate of coastal wetland loss was statistically significant when results from this study were compared to the coastal wetland loss estimates from 1998 to 2004.
Presented by Dr. James Meldrum, Institute of Behavioral Science, Western Water Assessment, University of Colorado Boulder . February 11, 2015.
This presentation is about the larger context of water availability in the United States and the interactions among water resources, climate change, and energy. We will start by discussing the main ways that people currently use water and the implications these have for water stress and its spatial distribution across the conterminous US. We then look forward, where consideration of the integrated climate-energy-water system becomes necessary to fully understand the individual risk profile of each sector. This webinar is targeted toward improving understanding of such interactions and their potential impacts on future water availability.
Presented by Caroline M. Williams, University of Florida, and Jessica J. Hellmann, University of Notre Dame. July 10, 2012.
A rapidly changing global climate has the potential to disturb ecosystem services, diminish endangered and economically important species, and increase pest outbreaks. Winter temperatures are changing rapidly and have important effects on organismal fitness that are often overlooked. In this talk, we will explore the impacts of changing winter conditions on insects, an economically and ecologically important group that are highly sensitive to temperature changes. We will look at winter through the lens of energetics, and explore the impact of thermal variability and local adaptation on determining the vitality of insect populations.
Presented by Dr. James R. Winton, Chief, Fish Health Section, Western Fisheries Research Center, August 2010.
In spite of obvious impacts to humans and captive animals, disease is often ignored by fisheries managers as a significant factor affecting the abundance of wild populations because the effects are difficult to observe and quantify. Historically, most fish health research has been directed towards identification, treatment, and prevention of diseases of hatchery fishes; however, more recent studies from marine, freshwater and terrestrial environments indicate that infectious and parasitic diseases can be responsible for population oscillations, extinction of endangered species, reduced host fitness and increased susceptibility to predation as well as an important component of natural mortality. The recognition of disease as a population-limiting factor for wild fish is partly the result of the emergence of high profile pathogens and changes in environmental conditions that shift the host-pathogen balance in favor of disease. This presentation will review some of the ways in which climate change is predicted to affect the ecology of fish diseases and will use several examples of endemic and emerging diseases in wild fish that have been associated with population-level effects. These examples will highlight the critical role played by environmental conditions in the ecology of fish diseases.
Presented by Dr. Jason Rohr, Department of Integrative Biology, University of South Florida. August 19, 2014.
In this talk, Dr. Rohr will discuss the effects of the herbicide atrazine on disease risk and health of amphibian populations and some of the controversy surrounding this research. Additionally, I will highlight work on the effects of climate change on amphibian declines associated with the disease chytridiomycosis.
Presented by Ken Rosenberg, Cornell Lab of Ornithology and Alicia F. King, U.S. Fish and Wildlife Service Migratory Bird Program, October 25, 2011.
Each year, the State of the Birds report provides policy makers, conservation organizations, and the general public with important scientific data along with a “call to action” to improve the conservation status of birds and their habitats. The State of the Birds 2011 focuses on birds on public lands and public waters and provides the nation’s first assessment of the distribution of birds on public lands. Join us to explore on-the-ground science focused on birds and their habitats and discover how the report can help prioritize and plan management strategies.
Presented by Dr. Serge Wich, Professor, Research Centre in Evolutionary Anthropology and Palaeoecology, Liverpool John Moores University. July 2, 2013.
Globally biodiversity continues to decline. An urgent need of conservation workers is to have timely data available on habitat changes, the presence and density of animals, biodiversity, and on threats. Currently conservationists use a mixture of ground and manned aerial surveys for this in combination with satellite images. Some of this data collection is costly and therefore cannot be collected at the frequency needed to properly monitor changes to be able to react in a timely fashion. We present a new tool for the conservationist toolbox to collect such data, the unmanned aerial vehicle (UAV). We developed and tested low-cost UAV’s (dubbed ConservationDrones) to be easy to operate and fly fully autonomously to take high-resolution photos and video. Photos from these flights have a resolution that is much higher (2cm/pixel) than high-resolution satellite images (50cm/pixel) and can be used to detect wildlife directly or indirectly by detecting nests (such as from orangutans) for instance. Photos can also be used to identify tree species. Photos can also be stitched together into high-resolution georeferenced mosaics or into 3D models, which both can be used to assess land-use type and structure in high detail. HD video can also be used to detect land use changes, wildlife, fires, logging, and other threats. These low-cost drones can thus be used to collect a wealth of relevant data for conservationists, researchers, ecologist, and others. In this presentation we provide an overview of the conservationdrones, data that have been collected with these in Indonesia, Malaysia and Nepal, and discuss some future developments and applications.
Presented by Karen Nelson, U.S. Fish and Wildlife Service, Environmental Contaminants Program, Helena, MT, January 10, 2012.
This webinar will provide a short overview of oil spill response activities on the Yellowstone River, and more detailed information on the integration of the USFWS into Wildlife Operations. For much of the spill, 4 Service personnel were on-site, these individuals represented 9 states, 4 regions, and at least 5 programs. We will discuss the hurdles we faced during response, as well as some of the lessons learned. The Silvertip Incident was the first major spill to occur in the state since the mid 80's. As a result, this was the first time many State and Federal officials worked a spill.
Presented by Dr. Richard Brown, Chief Research Scientist, Ecology Group, Pacific Northwest National Laboratory. October 21, 2014.
Freshwater fishes are one of the most imperiled groups of vertebrates, and population declines are alarming in terms of biodiversity and to communities that rely on fisheries for their livelihood and nutrition. One activity associated with declines in freshwater fish populations is water resource development, including dams, weirs, and hydropower facilities. Fish passing through irrigation and hydro infrastructures during downstream migration experience a rapid decrease in pressure, which can lead to injuries (barotrauma) that contribute to mortality. There is renewed initiative to expand hydropower and irrigation infrastructure to improve water security and increase low-carbon energy generation. The impact of barotrauma on fish must be understood and mitigated to ensure that development is sustainable for fisheries. This will involve taking steps to expand the knowledge of barotrauma-related injury from its current focus, mainly on seaward-migrating juvenile salmonids of the Pacific Northwest, to incorporate a greater diversity of fish species and life stages from many parts of the world. This article summarizes research that has examined barotrauma during fish passage and articulates a research framework to promote a standardized, global approach. The suggested approach provides clearly defined links to adaptive development of fish friendly technologies, aimed at mitigating the threats faced by global freshwater fisheries from the rapid expansion of water infrastructure.
Presented by Dr. Thomas Mueller, Biodiversity and Climate Research Centre, Goethe University Frankfurt and Dr. Sarah J. Converse, Research Ecologist, USGS Patuxent Wildlife Research Center. June 24, 2014.
Reintroductions of whooping cranes are an ongoing effort and birds have been released into the wild for over a decade. A large portion of the artificially reared birds undergo a training program with ultralight aircraft where the first liftime migration from Wisconsin to Florida is guided by ultralight aircraft. Intensive monitoring of subsequent migration has resulted of one of the most complete data bases for migrating animals. In the first part of the webinar we will talk about how learning of migration takes place, in particular what role individual learning, social learning and genetic aspects play. The second part will discuss the particular conservation challenges related to the reintroduction program.
Presented by Dr. Sean Brennan, University of Washington. October 14, 2015.
The diverse population structure of Pacific salmon, variation in their life history strategies, and access to intact heterogeneous habitats, buffer their regional productivity from perturbations. However, insights into freshwater habitat productivity at fine spatial scales, variation in habitat-use strategies of juveniles prior to ocean-migration, and how these two ecological dimensions influence overall production of salmon and respond to disturbances are difficult to obtain, especially in large and remote areas, such as Alaska. Recent research in Alaska has shown how variation in strontium isotope ratios within watersheds is able to simultaneously determine both i) natal origins at relatively small spatial scales and ii) variation in life history strategies of individuals and populations harvested in coastal fisheries. Strontium isotope ratios of river waters vary within and among watersheds as a function of geologic diversity; these ratios act as a kind of natural tag that is reliably recorded in the otoliths of fish via a 1:1 relationship over the course of an individual’s life, unmodified by physiological or environmental effects. Thus, strontium isotope records within the otoliths of fish combined with robust baseline isotope maps of all potential habitats represent a viable tool to delineate inter-annual production of freshwater habitats and freshwater life history strategies. Here, we present the findings of strontium isotope-based mixed stock analyses of Chinook salmon incidentally caught in Nushagak Bay, the terminus of one of Alaska’s largest, most remote, and productive rivers, which flows into Bristol Bay. Generating time-series, which elucidate these patterns annually from population aggregates captured in coastal fisheries or termini of large rivers, will also provide a framework for investigating how these production patterns covary with environmental parameters of freshwater habitats.
Presented by Dr. Lisa Hayward Watts, Communications Specialist, Northwest Climate Science Center, University of Washington. June 11, 2014.
USDA Forest Service (FS) is tasked with managing public lands for multiple uses, including as wildlife habitat and for recreation. Recent increases in motorized vehicle use in National Forests have greatly outpaced increases in population growth, with unclear impacts on wildlife. From 2005-2010 the University of Washington Center for Conservation Biology partnered with FS, Blue Ribbon Coalition and U.S. Fish and Wildlife Service with money from the California Off-Highway Vehicle Recreation Commission to investigate the impacts of motorcycle use on the federally threatened northern spotted owl in California. They found that acute exposure to motorcycles increased circulating glucocorticoids (“stress steroids”) in northern spotted owls, and that this response was context-dependent. They also found that northern spotted owls with summer roosts near busy roads had significantly lower reproductive success than owls roosting near unused roads.
Presented by Dr. Nina Bednarsek, NOAA Pacific Marine Environmental Laboratory. March 19, 2015.
The ocean uptake of anthropogenic CO2 has shoaled the aragonite saturation horizon in the California Current Ecosystem, but only a few studies to date have demonstrated widespread biological impacts of ocean acidification under present-day conditions. Pteropods are especially important for their role in carbon flux and energy transfer in pelagic ecosystems. In the California Current Ecosystem, conditions are becoming increasing unfavorable for sustaining pteropod population. In my work, combination of different approaches, ranging from observations, experimental work and modelling are used for more comprehensive understanding and forecast of pteropod responses due to ocean acidification. Our results show a strong positive correlation between pteropods with severe shell dissolution and the extent of undersaturated water. From this relationship, we also determined the extent of shell dissolution for the pre-industrial era, 2011, and 2050. Our calculations show that shell dissolution has increased by 30% since the beginning of the industrial era, and could increase to 70% by 2050. Although dissolution is occurring in most of the investigated pteropod species, some species have changed their daily vertical distribution pattern by migrating to upper supersaturated waters to avoid corrosive waters, a potential indication of an adaptation strategy to ocean acidification. Preliminary results of calcification and survival abilities in pteropods demonstrate that coastal pteropod population is already under increased effect of ocean acidification.
Presented by Dr. Judith Z. Drexler, California Water Science Center, U.S. Geological Survey. September 10, 2013.
Wetlands are highly sensitive to changes in hydrology and can be used as sentinels for climate change. Peat-forming wetlands are also important carbon sinks, which makes them valuable mitigators of carbon pollution. In this seminar, I will discuss research in the Sierra Nevada Mountains of California in which I used fens (groundwater-fed peatlands) as gauges for long-term changes in groundwater recharge due to climate change. In addition, I will present a study in which I compared carbon storage rates in naturally tidal versus impounded freshwater marshes in South Carolina. The results from this study show that management regime exerts a strong influence on carbon sequestration rates. Small changes in management could improve carbon storage in wetlands throughout the National Wildlife Refuge system.
Presented by Dr. Hazel Barton, Associate Professor, Department of Biological Sciences and Ashland Endowed Professor of Integrative Science, Northern Kentucky University, October 6, 2011.
What is the current status and range of white-nose syndrome and what are researchers doing to try and stop the spread of the fungus to new bat populations?
Presented by Dr. Barbara Mahler, Research Hydrologist, USGS Texas Water Science Center. August 18, 2015.
Coal-tar-based sealcoat is used to protect and beautify the asphalt pavement of driveways and parking lots primarily in the central, southern, and northeastern U.S. and in Canada. Coa-tar sealcoat typically is 20 to 35% crude coal tar or coal-tar pitch and contains from 50,000 to 100,000 mg/kg PAHs, about 1,000 times more than asphalt-based sealcoat or asphalt itself. Tires and snowplows abrade the friable sealcoat surface into fine particles—PAH concentrations in fine particles (dust) from coal-tar-sealcoated pavement are about 1,000 times higher than in dust from asphalt-sealcoated pavement (median total PAH concentrations 2,200 and 2.1 mg/kg, respectively). Use of coal-tar sealcoat has several implications for urban streams and lakes. Source apportionment modeling has indicated that, in regions where coal-tar sealcoat is prevalent, particles from sealcoated pavement are contributing the majority of the PAHs to recently deposited lake sediment, with implications for impact on aquatic habitats. Acute 2-day laboratory toxicity testing of simulated runoff from coal-tar-sealcoated pavement to stream biota, demonstrated for a cladoceran (Ceriodaphnia dubia) and fathead minnows (Pimephales promelas) demonstrated that toxicity continues for samples collected for weeks or months following sealcoat application. Using the fish-liver cell line RGL-W1, runoff collected as much as 36 days following coal-tar-sealcoat application has been demonstrated to cause DNA damage and impair DNA repair capacity. These results demonstrate that runoff from coal-tar-sealcoated pavement is a potential hazard to aquatic ecosystems for at least several weeks after sealant application, and that exposure to sunlight can enhance toxicity and genetic damage. Recent research has provided direct evidence that restricting use of CT sealcoat in a watershed can lead to a substantial reduction in PAH concentrations in receiving water bodies.