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At least 739 records · Page 41Linked to original sources

Sulfur in the South Florida ecosystem: Distribution, sources, biogeochemistry, impacts, and management for restoration

Sulfur is broadly recognized as a water quality issue of significance for the freshwater Florida Everglades. Roughly 60% of the remnant Everglades has surface water sulfate concentrations above 1 mg l-1, a restoration performance measure based on present sulfate levels in unenriched areas. Highly enriched marshes in the northern Everglades have average sulfate levels of 60 mg l-1. Sulfate loading to the Everglades is principally a result of land and water management in South Florida. The highest concentrations of sulfate (average 60-70 mg l-1) in the ecosystem are in canal water in the Everglades Agricultural Area (EAA). Potential sulfur sourcesin the watershed are many, but geochemical data and a preliminary sulfur mass balance for the EAA are consistent with sulfur presently used in agricultural, and sulfur released by oxidation of organic EAA soils (including legacy agricultural applications and natural sulfur) as the primary sources of sulfate enrichment in the EAA canals. Sulfate loading to the Everglades increases microbial sulfate reduction in soils, leading to more reducing conditions, greater cycling of nutrients in soils, production of toxic sulfide, and enhanced methylmercury (MeHg) production and bioaccumulation. Wetlands are zones of naturally high MeHg production, but the combination of high atmospheric mercury deposition rates in South Florida and elevated sulfate loading leads to increased MeHg production and MeHg risk to Everglades wildlife and human consumers. Sulfate from the EAA drainage canals penetrates deep into the Everglades Water Conservation Areas, and may extend into Everglades National Park. Present plans to restore sheet flow and to deliver more water to the Everglades may increase overall sulfur loads to the ecosystem, and move sulfate-enriched water further south. However, water management practices that minimize soil drying and rewetting cycles can mitigate sulfate release during soil oxidation. A comprehensive Everglades restoration strategy should include reduction of sulfur loads as a goal because of the many detrimental impacts of sulfate on the ecosystem. Monitoring data show that the ecosystem response to changes in sulfate levels is rapid, and strategies for reducing sulfate loading may be effective in the near term. A multifaceted approach employing best management practices for sulfur in agriculture, agricultural practices that minimize soil oxidation, and changes to stormwater treatment areas that increase sulfate retention could help achieve reduced sulfate loads to the Everglades, with resulting benefits.

Florida↗

2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents in tissues of birds at Green Bay, Wisconsin, USA

The environment has become contaminated with complex mixtures of planar, chlorinated hydrocarbons (PCHs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p -dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and structurally similar compounds. Because the potencies of individual congeners to cause the same adverse effects vary greatly and the relative as well as absolute concentrations of individual PCH vary among samples from different locations, it is difficult to assess the toxic effects of these mixtures on wildlife. These compounds can cause a number of adverse effects, however, because the toxic effects which occur at ecologically-relevant concentrations such as embryo-lethality and birth defects appear to be mediated through the same mechanism, the potency of individual congeners can be reported relative to 2,3,7,8-tetrachlorodibenzo- p -dioxin (2,3,7,8-TCDD) which is the most toxic congener in the PCH class. The concentations of 2,3,7,8-TCDD Equivalents (TCDD-EQ) were determined in the tissues of aquatic and terrestrial birds of Green Bay, Wisconsin by the H4IIE bioassay system and compared toxic equivalency factors (TEFs) with the concentration predicted by the use of toxic equivalency factors applied to concentrations of PCH, which were determined by instrumental analyses. Concentrations of TCDD-EQ ranged from 0.52 to 440 ng/kg, wet weight. The greatest concentrations occurred in the fish-eating birds. Concentrations of TCDD-EQ, which were determined by the two methods were significantly correlated, but the additive model which used the TEFs with concentrations of measured PCB, PCDD and PCDF congeners underestimated the concentrations of TCDD-EQ measured by the H4IIE bioassay by an average of 57%. This is thought to be due to contributions from un-quantified PCH, which are known to occur in the environment. Of the quantified PCH congeners, PCDD and PCDF contributed a small portion of the TCDD-EQ in the aquatic birds, while most of the TCDD-EQ were due to non-ortho-substituted PCBs. In the terrestrial birds, the proportion of the TCDD-EQ contributed by the PCDD and PCDF was greater. This paper has been reviewed in accord with U.S. Environmental Protection Agency policy. Mention of specific products or trade names does not imply endorsement by the U.S. Government.

Archives of Environmental Contamination and Toxico↗

Simulation modeling to assess line transect distance sampling under a range of translocation scenarios

The accuracy of posttranslocation population monitoring methods is critical to assessing long-term success in translocation programs. Translocation can produce unique challenges to monitoring efforts; therefore, it is important to understand the flexibility and robustness of commonly used monitoring methods. In Florida, USA, thousands of gopher tortoises Gopherus polyphemus have been, and continue to be, translocated from development sites to permitted recipient sites. These recipient sites create a broad range of potential monitoring scenarios due to variability in soft-release strategies, habitat conditions, and population demographics. Line transect distance sampling is an effective method for monitoring natural tortoise populations, but it is currently untested for translocated populations. We therefore produced 3,024 individual-based, spatially explicit scenarios of translocated tortoise populations that differed in recipient site and tortoise population properties, based on real-world examples, literature review, and expert opinion. We virtually sampled simulated tortoise populations by using line transect distance sampling methods and built a Bayesian hierarchical model to estimate the population density for each simulation, which incorporated individual-level covariates (i.e., burrow width and burrow occupancy). Line transect distance sampling was largely appropriate for the conditions that typify gopher tortoise recipient sites, particularly when detection probability on the transect lines was greater than or equal to 0.85. Designing the layout of transects relative to the orientation of soft-release pens, to avoid possible sampling biases that lead to extreme outliers in estimates of tortoise densities, resulted in more accurate population estimates. We also suggest that use of individual-level covariates, applied using a Bayesian framework as demonstrated in our study, may improve the applicability of line transect distance sampling surveys in a variety of contexts and that simulation can be a powerful tool for assessing survey design in complex sampling situations.

Florida↗

Predation on waterfowl in arctic tundra and prairie breeding areas: A review

Predation is a natural component of waterfowl population biology, but environmental alterations have changed the magnitude and importance of predation on waterfowl breeding areas. We reviewed the status of waterfowl populations, adaptations of waterfowl that minimize impacts of predation, and the impacts of predation on waterfowl populations in 2 major North American breeding areas, the Arctic and Prairie Regions. We identified the underlying factors contributing to most waterfowl predation problems to be changes in essential breeding habitats and changes in predator community composition and abundance. In the Arctic, high predation rates on waterfowl eggs and young are usually associated with predators gaining access to populations that were previously isolated. In the prairie, predation problems are often related to large-scale habitat degradation coupled with changes in predator communities. Predation problems are often symptomatic of inadequate habitat management, but we recognize that habitat management alone is not always sufficient to effectively manage predation problems. Predation management efforts should be integrated with strategies of long-term management of habitats critical to breeding waterfowl, strategies embraced by the North American Waterfowl Management Plan. Predation management must be tailored to different situations and include an element of flexibility that allows appropriate response to the dynamic nature of factors influencing survival and recruitment.

Wildlife Society Bulletin↗

Storeria occipitomaculata (Red-bellied Snake)

STORERIA OCCIPITOMACULATA (Red-bellied Snake). USA: LOUISIANA: St. Mary Parish: Bayou Teche National Wildlife Refuge (29.69425N, 91.46701W; WGS 84). 18 August 2022. William C. Carroll and Aidan G. Phillips. Verified by Coleman M. Sheehy III. Florida Museum of Natural History, University of Florida (UF 193423; photo voucher). Adult photographed in leaf litter in a wet bottomland hardwood forest with a mixed composition of hardwood trees and Dwarf Palmetto (Sabal minor). New parish record (Dundee and Rossman 1989. The Amphibians and Reptiles of Louisiana. Louisiana State University Press, Baton Rouge, Louisiana. 300 pp.). The snake was found 68.5 km to the east-southeast from the nearest other documented specimen in Vermilion Parish (UF 177730; Muse et al. 2016. Herpetol. Rev. 47:266). This record is the second documentation of S. occipitomaculata in a coastal Louisiana parish (Muse et al. 2016, op. cit.). These two recent findings challenge our previous understanding that this species is absent from coastal parishes (Boundy and Carr 2017. Amphibians & Reptiles of Louisiana: An Identification and Reference Guide. Louisiana State University Press, Baton Rouge, Louisiana. 282 pp.). Storeria occipitomaculata is fossorial and can be difficult to locate, but these two recent records suggest additional populations may yet be discovered where suitable forested habitat exists along the coast.

Louisiana↗

An overview of sea otter studies

The Exxron Valdez oil spill (EVOS) on 24 March 1989 threatened extensive areas of prime sea otter ( Enhydra lutris ) habitat along the coasts of south-central Alaska. The spill occurred in northeastern Prince William Sound (PWS), and oil moved rapidly south and west through PWS into the Gulf of Alaska. Much of the coastline of western PWS was heavily oiled, and the slick eventually spread as far southwest as Kodiak Island and the Alaska Peninsula (Galt and Payton 1990; Morris and Loughlin, Chapter 1). All coastal waters affected by the spill were inhabited by sea otters. Concern for the survival of sea otters following the oil spill was immediate and well founded. Sea otters are particularly vulnerable to oil contamination because they rely on pelage rather than blubber for insulation, and oiling drastically reduces the insulative value of the fur (Costa and Kooyman 1982; Siniff et al. 1982; Geraci and Williams 1990). Within days of the spill, recovery of oiled live otters and carcasses began. During the several months following the spill, sea otters became symbolic of the mortality associated with the spilled oil, and of the hope for rescue and recovery of injured wildlife (Batten 1990). An extensive sea otter rescue and rehabilitation effort was mounted in the weeks and months following the spill. Handling and treatment of the captive sea otters posed an enormous and difficult challenge, given the large number of otters held at the facilities and minimal prior experience in caring for oiled sea otters. Rehabilitation of sea otters was a separate effort from the postspill studies designed to evaluate injury to the otter populations and is not addressed in this chapter only as it relates to evaluation of damage assessment studies. Detailed information on the rehabilitation effort is presented in Bayha and Kormendy (1990) and Williams and Davis (1990). Sea otters retained a high profile in the Natural Resource Damage Assessment (NRDA) studies largely because the initial injury to the sea otter population was readily demonstrable, but also because of concerns about long-term damages. The scope of the postspill studies to assess oil-related damages to sea otters was extensive: From 1989 through 1993, more than $3,000,000 was spent, and more than 20 scientists were involved in a comprehensive research program. The studies were predominantly directed at sea otter populations in PWS. Damages to sea otters generally can be classified as either acute, defined as spill-related deaths occurring during the spill, or chronic, defined as longer term lethal or sublethal oil-related injuries. Studies of acute damages focused on estimating the total initial loss of sea otters. Characterization of the pathologies associated with exposure to oil was a secondary goal of studies of acute effects. Chronic or longer term damages may have resulted from sublethal initial exposure or continued exposure to hydrocarbons persisting in the environment. Studies of chronic effects included evaluating abundance and distribution, survival and reproduction rates, foraging behavior, and pathological, physiological, and toxicological changes in the years following the spill. The objective of this chapter is to review the studies conducted on sea otters in response to the EVOS and to synthesize the major findings of those studies relative to injury to the sea otter population associated with exposure to oil. We also provide recommendations for research to improve our understanding of the effects of future oil spills on Sea otter populations.

Alaska↗

Appendix 6: Overview of iPOM 2.0: Updates to wolf abundance estimation in Montana

Montana Fish, Wildlife and Parks (MFWP) uses the integrated Patch Occupancy Model (iPOM) to estimate statewide and regional wolf abundance. During the early years of recovery, wolf abundance was tracked using minimum counts. As the population increased, limitations of this method became apparent, motivating development of a model-based approach for estimating abundance. iPOM development began in 2006, was operationalized in 2013, and has been used in its current form (iPOM 1.0) since 2021. Since its inception, iPOM has been developed and presented as an adaptive modeling framework intended to evolve as new data and analytical methods become available1. Here, we briefly present ongoing work to produce the next iteration of iPOM, hereafter iPOM 2.0, and summarize major model updates and resulting preliminary wolf abundance estimates. iPOM uses models for occupancy, territory size, and pack size, along with monitoring data collected by MFWP wolf specialists and potential wolf sightings reported by deer and elk hunters during the 5-week general rifle season each Nov-Dec. These monitoring data, wolf sightings, and covariates for habitat and survey effort are used to model occupancy of packs on a statewide grid of 600-km 2 cells. The area used by wolves is then estimated as each cell’s occupancy estimate multiplied by grid cell area. iPOM estimates pack abundance by dividing this area by predicted territory sizes, and in-pack wolf abundance by multiplying pack abundance by estimated group size. This is combined with a lone wolf rate to estimate total wolf abundance (see Sells et al. 1 for a full description of iPOM 1.0). This technical summary provides a high-level overview of the proposed iPOM updates and their implications for wolf abundance estimates. The estimates presented here represent results as of June 2026 and are provided to inform upcoming discussions surrounding harvest management and regulations (e.g., season dates, quotas, methods). Results are preliminary and remain subject to final model refinement and peer review.

Montana↗

Global warming and prairie wetlands: potential consequences for waterfowl habitat

The accumulation of greenhouse gasses in the atmosphere is expected to warm the earth's climate at an unprecedented rate (Ramanathan 1988, Schneider 1989). If the climate models are correct, within 100 years the earth will not only be warmer than it has been during the past million years, but the change will have occurred more rapidly than any on record. Many profound changes in the earth's environment are expected, including rising sea level, increasing aridity in continental interiors, and melting permafrost. Ecosystems are expected to respond variously to a rapidly changing climate. Tree ranges in eastern North American are expected to shift northward, and seed dispersal may not be adequate to maintain current diversity (Cohn 1989, Johnson and Webb 1989). In coastal wetlands, rising sea level from melting icecaps and thermal expansion could flood salt-grass marshes and generally reduce the size and productivity of the intertidal zone (Peters and Darling 1985). As yet, little attention has been given to the possible effects of climatic warming on inland prairie wetland ecosystems. These wetlands, located in the glaciated portion of the North American Great Plains (Figure 1), constitute the single most important breeding area for waterfowl on this continent (Hubbard 1988). This region annually produces 50-80% of the continent's total duck production (Batt et al. 1989). These marshes also support a variety of other wildlife, including many species of nongame birds, muskrat, and mink (Kantrud et al. 1989a). Prairie wetlands are relatively shallow, water-holding depressions that vary in size, water permanence, and water chemistry. Permanence types include temporary ponds (typically holding water for a few weeks in the springs), seasonal ponds (holding water from spring until early summer), semipermanent ponds (holding water throughout the growing season during most years), and large permanent lakes (Stewart and Kantrud 1971). Refilling usually occurs in spring from precipitation and runoff from melting snow on frozen or saturated soils (Figure 2). Annual water levels fluctuate widely due to climate variability in the Great Plains (Borchert 1950, Kantrud et al. 1989b). Climate affects the quality of habitat for breeding waterfowl by controlling regional water conditions--water depth, areal extent, and length of wet/dry cycles (Cowardin et al. 1988)--and vegetation patterns such as the cover ration (the ratio of emergent plant cover to open water). With increased levels of atmospheric carbon dioxide, climate models project warmer and, in some cases, drier conditions for the northern Great Plains (Karl et al. 1991, Manabe and Wetherald 1986, Mitchell 1983, Rind and Lebedeff 1984). In general, a warmer, drier climate could lower waterfowl production directly by increasing the frequency of dry basins and indirectly by producing less favorable cover rations (i.e., heavy emergent cover with few or no open-water areas). The possibility of diminished waterfowl production in a greenhouse climate comes at a time when waterfowl numbers have sharply declined for other reasons (Johnson and Shaffer 1987). Breeding habitat continues to be lost or altered by agriculture, grazing, burning, mowing, sedimentation, and drainage (Kantrud et al. 1989b). For example, it has been estimated that 60% of the wetland area in North Dakota has been drained (Tiner 1984). Pesticides entering wetlands from adjacent agricultural fields have been destructive to aquatic invertebrate populations and have significantly lowered duckling survival (Grue et al. 1988). In this article, we discuss current understanding and projections of global warming; review wetland vegetation dynamics to establish the strong relationship among climate, wetland hydrology, vegetation patterns, and waterflow habitat; discuss the potential effects of a greenhouse warming on these relationships; and illustrate the potential effects of climate change on wetland habitat by using a simulation model. The extent to which intensive management of the waterfowl resource will be needed in the future strongly depends on whether a changing climate exacerbates the current problem of waterfowl decline. Should this occur, efforts outlined the recent North American Waterfowl Management Plan between the United States and Canada to reduce the current decline (Patterson and Nelson 1988) may need to be redoubled in coming years.

BioScience↗

Methods for estimating vital rates of greater sage-grouse broods: A review

Biologists use a variety of methods to estimate productivity and resource selection of birds. The effectiveness and suitability of each method depends on the study's objectives, but is also influenced by many important traits, including detection probability, disturbance of focal birds and sampling frequency. We reviewed 504 greater sage-grouse Centrocercus urophasianus papers published from 1990 to 2019 to document the most common brood survey methods used by investigators and summarized if and how they used brood survey data to estimate brood survival and detection probability. Of the 504 papers, 16.1% (n = 81) had useful information relevant to the review. The most common methods included daytime visual surveys (46.9%; n = 38), daytime flush surveys (33.3%; n = 27), nocturnal spotlight surveys (19.8%; n = 16), radio-tagged chicks (16.0%; n = 13), wing surveys (9.9%; n = 8), brood routes (4.9%; n = 4) and pointing dogs (4.9%; n = 4). Fifty-nine of the 81 papers used >1 method, only 2 of the 81 papers measured or reported detection probability, and none reported the level of disturbance caused by the method. Studies varied widely regarding the age of the brood when brood fate was confirmed (x̄ = 44.4 days post-hatch, range 14–84 days). The frequency of brood sampling visits also varied greatly among studies (range = 1.19–3.85 surveys/brood/week) and this variation complicates comparison in fecundity and survival estimates across studies. Furthermore, 35 papers used >1 maternal behavior as purported indicators of brood fate, but none of them documented how accurate their indicators were. Future studies could reduce variance in estimates of sage-grouse fecundity and brood survival by employing empirical methods to estimate detection probability, standardizing brood sampling methods and conducting trials to document the effects of hen or brood capture, handling and flushing on brood survival estimates. Moreover, the accuracy of commonly used indicators of brood fate, including maternal behaviors, flocking behavior and distance moved after flush needs verification.

Wildlife Biology↗

Science-based management of public lands in southern Nevada

Landmark legislation provides guiding principles for land management planning in southern Nevada and the rest of the United States. Such legislation includes, but is not limited to, the Forest Service Organic Administration Act of 1897 (16 U.S>C. 473-478, 479-482 and 551), National Park Service Organic Act of 1916 (U.S.C. Title 16, Secs. 1-4). Wilderness Act 1964 (P.L.88-577), National Environmental Policy Act of 1969 (P.L. 91-190), Endangered Species Act of 1973 (P.L. 91-205), National Forest Management Act of of 1976 (P.L. 94-588), and Federal Land Policy and Management Act of 1976 (P.L. 94-579). The acts establishing congressionally designated areas within southern Nevada, such as Lake Mead National Recreation Area, Spring Mountains National Restoration Area, and Desert National Wildlife Refuge, also contain guidelines for the management of these lands. These documents variously require preservation of natural and cultural resource and wilderness character, protection of species, and prevention of undesirable environmental effects from land management actions. These requirements must be met while allowing for multiple "uses" of certain public lands (e.g. recreation, ranching, resources extraction, renewable energy development, etc.) to the degree that they do no threaten preservation, protection, and prevention goals,. many considerations some into play in the development and implementation for land management plans and actions. The planning process requires a balancing act that sometimes pit one need or priority against another. When priorities can trump other needs can prioritized and receive disproportionate consideration. Overall, the management of public lands is a very complicated and sometime contentious process. Science provides an objective way to help weigh quantifiable information and draw conclusions about the effects of past and potential future land management policies, decisions, and actions. When effectively integrated into adaptive management, science-based information can reduce uncertainties, increase knowledge, and improve decision making. However, the specific science information needed for effective management is often lacking or difficult to access or interpret. Science is typically reported in scientific journals as discrete units describing individual studies with other scientists as the primary audience. Translations of these studies an synthesis or multiple studies into formats that can be readily used in land management planning efforts are often lacking. Identifying and articulating the highest priority science and research needs is one of the primary purposes of the Southern Nevada Agency Partnership (SNAP; http://www.SNAP.gov) Science and Research Team (chapter 1; Turner and others 2009). The SNAP Science and Research Strategy (Strategy) calls for a synthesis report to be written every 5 years summarizing the state of knowledge, information gaps and management implications of scientific information as it relates to the SNAP Strategy goals (Turner and others 2009). This General Technical Report serves as the first SNAP Science and Research Synthesis Report (Synthesis Report) commissioned by the Science and Research Team. The Synthesis Report is mostly based on information form the peer-reviewed scientific literature, and is itself peer reviewed and constitutes a new contribution to the scientific literature. This final chapter addresses Sub-goal 2.3, which is to manage current and future authorized southern Nevada land uses in a manner that balances public need and ecosystem sustainability, and Sub-goal 2.5, which is to promote an effective conservation education and interpretation program to improve the quality of resources and enhance public use and enjoyment of southern Nevada public lands. It summarizes information form the previous chapters on what scientific information is known currently and what remains largely unknown, and it discusses how science can be used to make future management decisions that balances public needs and ecosystem sustainability.

Nevada↗

Postmortem evaluation of reintroduced migratory whooping cranes (Grus americana) in eastern North America

We reviewed necropsy records of 124 Whooping Cranes ( Grus americana ) recovered following reintroduction of 268 individuals from 2001 to 2016 in the eastern US. Causes of death were determined in 62% (77/124) of cases facilitated by active monitoring that limited decomposition and scavenging artifact. The greatest proportions of mortality were caused by predation (0.468; 95% confidence interval 0.356–0.580; 36/77), collision with power lines or vehicles (0.260; 0.162–0.358; 20/77), and gunshot (0.169; 0.085–0.253; 13/77). Six deaths were attributed to infection (0.078; 0.018–0.138; 6/77), including bacterial and fungal etiologies. Lead analysis of 50 liver samples yielded two results with elevated concentrations (3.65 and 10.97 ppm wet weight), and 10 bone samples from partial carcasses lacking suitable liver tissue resulted in one elevated result (48.82 ppm dry weight). These data indicate that underlying subclinical or clinical lead toxicosis may be a factor in up to 5% of deaths attributed to predation or impact trauma. Brain cholinesterase activity testing indicated no exposure to organophosphate or carbamate pesticides (mean±SD=17.32±2.90 µmol/min/g, 31/71). The causes of death and potential underlying factors summarized in this study constitute the first definitive mortality survey of migratory Whooping Cranes based on a high carcass recovery rate. Causes of death by infectious etiologies remained comparatively rare in this study, and occurred as single cases with no evidence of sustained transmission among reintroduced Whooping Cranes.

Eastern North America↗

Environmental fate and effects of the lampricide Bayluscide: A review

Bayluscide is an additive to TFM that increases the effectiveness of TFM as a lampricide. A review of the literature was undertaken to determine the environmental fate and effects of Bayluscide. Niclosamide (2′, 5-dichloro-4′-nitrosalicylanilide), the active ingredient of Bayluscide, degrades rapidly in natural water and sediment systems, however, the rate of degradation is very slow in autoclaved samples. This difference suggests that degradation under laboratory conditions is dependent on microbial activity and hydrolysis plays a minor role in degradation of niclosamide. The major degradation product of niclosamide has been reported to be aminoniclosamide (2′,5-dichloro-4′-aminosalicylanilide), which represented more than 50% of the residues extractable from sediments. Significantly more of the chemical is adsorbed to sediments with higher organic content and at lower pH's. The mobility of niclosamide in soil can be characterized as slight to medium; the estimated leaching distance would range from 0 to > 25 cm depending on the soil type and pH. The active ingredient of Bayluscide (niclosamide) is decomposed by ultra-violet light depending on the intensity and duration of the exposure. The uptake of residues by most invertebrates exposed to 14 C-niclosamide is fairly rapid and equilibrium is reached within 24 h. About 90% of the accumulated residues were lost within 48 h after the organisms were transferred to clean flowing water. As with invertebrates, fish rapidly accumulate and eliminate residues of niclosamide. Three distinct residues were isolated from the extracts of edible fillet tissue; parent niclosamide, the glucuronide conjugate of niclosamide, and the sulfate ester of niclosamide. Aquatic plants and agricultural crops do not appear to be adversely affected at concentrations of Bayluscide used for lamprey or snail control. Mayflies ( Hexagenia sp .). tend to be susceptible to TFM, but are relatively resistant to the effects of exposure to Bayluscide. Bayluscide was originally developed as a molluscicide to eliminate snails. Therefore, it is not surprising that mollusks are extremely sensitive to Bayluscide. Oral, dermal, and ocular administration of Bayluscide to mammals resulted in no clinical signs of systemic toxicity. Tests of the chronic effects of Bayluscide indicated that it is not mutagenic or carcinogenic. Bayluscide is not persistent in the environment; it breaks down in natural water and sediment systems through hydrolysis, photolysis, and microbial degradation. Given the limited use and tight control maintained by the U.S. Fish and Wildlife Service during applications of lampricides, Bayluscide presents minimal risk to human health and safety of the environment.

Conference Paper↗

Environmental fate and effects of the lampricide bayluscide: a review

Bayluscide is an additive to TFM that increases the effectiveness of TFM as a lampricide. A review of the literature was undertaken to determine the environmental fate and effects of Bayluscide. Niclosamide (2', 5-dichloro-4'-nitrosalicylanilide), the active ingredient of Bayluscide, degrades rapidly in natural water and sediment systems, however, the rate of degradation is very slow in autoclaved samples. This difference suggests that degradation under laboratory conditions is dependent on microbial activity and hydrolysis plays a minor role in degradation of niclosamide. The major degradation product of niclosamide has been reported to be aminoniclosamide (2',5-dichloro-4'-aminosalicylanilide), which represented more than 50% of the residues extractable from sediments. Significantly more of the chemical is adsorbed to sediments with higher organic content and at lower pH's. The mobility of niclosamide in soil can be characterized as slight to medium; the estimated leaching distance would range from 0 to > 25 cm depending on the soil type and pH. The active ingredient of Bayluscide (niclosamide) is decomposed by ultra-violet light depending on the intensity and duration of the exposure. The uptake of residues by most invertebrates exposed to super(14)C-niclosamide is fairly rapid and equilibrium is reached within 24 h. About 90% of the accumulated residues were lost within 48 h after the organisms were transferred to clean flowing water. As with invertebrates, fish rapidly accumulate and eliminate residues of niclosamide. Three distinct residues were isolated from the extracts of edible fillet tissue; parent niclosamide, the glucuronide conjugate of niclosamide, and the sulfate ester of niclosamide. Aquatic plants and agricultural crops do not appear to be adversely affected at concentrations of Bayluscide used for lamprey or snail control. Mayflies (Hexagenia sp.). tend to be susceptible to TFM, but are relatively resistant to the effects of exposure to Bayluscide. Bayluscide was originally developed as a molluscicide to eliminate snails. Therefore, it is not surprising that mollusks are extremely sensitive to Bayluscide. Oral, dermal, and ocular administration of Bayluscide to mammals resulted in no clinical signs of systemic toxicity. Tests of the chronic effects of Bayluscide indicated that it is not mutagenic or carcinogenic. Bayluscide is not persistent in the environment; it breaks down in natural water and sediment systems through hydrolysis, photolysis, and microbial degradation. Given the limited use and tight control maintained by the U.S. Fish and Wildlife Service during applications of lampricides, Bayluscide presents minimal risk to human health and safety of the environment.

Journal of Great Lakes Research↗

Ducks and passerines nesting in northern mixed-grass prairie treated with fire

Prescribed fire is an important, ecology-driven tool for restoration of grassland systems. However, prescribed fire remains controversial for some grassland managers because of reported reductions in bird use of recently burned grasslands. Few studies have evaluated effects of fire on grassland bird populations in the northern mixed-grass prairie region. Fewer studies yet have examined the influence of fire on nest density or survival. In our review, we found no studies that simultaneously examined effects of fire on duck and passerine nesting. During 1998—2003, we examined effects of prescribed fire on the density of upland-nesting ducks and passerines nesting in north-central North Dakota, USA. Apparent nest densities of gadwall ( Anas strepera ), mallard ( A. platyrhynchos ), and all duck species combined, were influenced by fire history of study units, although the degree of influence was not compelling. Fire history was not related to nest densities of blue-winged teal ( A. discors ), northern shoveler ( A. clypeata ), or northern pintail ( A. acuta ); however, apparent nest densities in relation to the number of postfire growing seasons exhibited a strikingly similar pattern among all duck species. When compared to ducks, fire history strongly influenced apparent nest densities of clay-colored sparrow ( Spizella pallida ), Savannah sparrow ( Passerculus sandwichensis ), and bobolink ( Dolichonyx oryzivorus ). For most species examined, apparent nest densities were lowest in recently burned units, increased during the second postfire growing season, and stabilized or, in some cases, decreased thereafter. Prescribed fire is critical for restoring the ecology of northern mixed-grass prairies and our findings indicate that reductions in nest densities are limited mostly to the first growing season after fire. Our results support the premise that upland-nesting ducks and several grassland passerine species are adapted to periodic fires occurring at a frequency similar to that of pre-Euro-American settlement of the region.

North Dakota↗

Crocodylus acutus (American Crocodile). Long distance juvenile movement

Crocodylus acutus (American Crocodile) is the most widely distributed New World crocodilian species with its range extending from Peru in the south to the southern tip of peninsular Florida in the north. Crocodylus acutus occupies primarily coastal brackish water habitat, however it also occurs in freshwater to hypersaline habitats (Thorbjarnarson 2010. In Crocodiles. Status Survey and Conservation Action Plan. [Third Edition], American Crocodile Crocodylus acutus, pp. 46–53 S.C. Manolis and C. Stevenson. Crocodile Specialist Group, Darwin). There is limited literature on long distance movements of juvenile crocodilians worldwide and no literature on juvenile crocodiles in Florida. However, adult C. acutus in Florida have been documented to make seasonal movements of 5–15 km from preferred foraging habitat to nesting beaches (Mazzotti 1983. The Ecology of Crocodylus acutus in Florida. PhD Dissertation. The Pennsylvania State University, University Park, Pennsylvania. 161pp), and one adult was documented making a 35 km trip from her nest site to preferred foraging habitat (Cherkiss et. al. 2006. Herpetol. Rev. 38:72–73). Rodda (1984. Herpetologica 40:444–451) reported on juvenile C. acutus movement in Gatun Lake, Panama, and found that juveniles stayed within 1 km of their nest site for the first month. Movements of juvenile Crocodylus porosus (Saltwater Crocodile) in a river system in Northern Australia showed a maximum movement of 38.9 km from a known nest site, with the majority of the crocodiles staying within 15.6 km downstream to 6.8 km upstream (Webb and Messel 1978. Aust. Wildlife Res. 5:263–283). Juvenile movement of Crocodylus niloticus (Nile Crocodile) in Lake Ngezi, Zimbabwe showed crocodiles restricted their movements from 1.0 km up to 4.5 km through the wet and dry seasons (Hutton 1989. Am. Zool. 29:1033–1049). Long distance movements of alligators were recorded for sizes ranging from 28 cm to 361 cm in a coastal refuge in Louisiana, where the distance traveled ranged from 0.3 km to 90.2 km. The data showed that the smaller alligators moved greater distance than larger ones (Lance et al. 2011. Southeast Nat. 10:389–398). An ongoing 30 year mark and recapture study for Crocodylus acutus in Florida allowed us to look at long distance movement (>30 km) of juveniles (30km). Initial and most recent captures as a juvenile were used to analyze distances moved (Fig. 1). These distances were measured linearly between capture locations. Maximum linear distances of 76.3 km and 69.6 km were recorded for animals 4838 and 6662. All crocodiles moved from nesting habitat through potentially optimal nursery habitat prior to reaching their recapture locations. These juvenile long distance movements could be due to larger crocodiles facilitating their dispersal from the nest location (Lance et al. 2011. op. cit.). These data (Table 1.) support that there is exchange of individuals among the nesting colonies and our ongoing efforts to monitor this threatened species allow us to make observations of how juvenile crocodiles are moving throughout the landscape in an ecosystem currently undergoing restoration.

Herpetological Review↗

Enhanced between-site biosecurity to minimize herpetofaunal disease-causing pathogen transmission

Pathogens and their associated diseases have the potential to severely affect wildlife populations, including herpetofauna. Concern is increasing for transmission pathways of herpetofaunal diseases, especially for amphibians affected by the fungal pathogens Batrachochytrium dendrobatidis (Bd: Longcore et al. 1999) and B. salamandrivorans (Bsal: Martel et al. 2013), and amphibians and reptiles affected by Iridoviruses of the genus Ranavirus (Rv: Gray and Chinchar 2015) for which global human-mediated pathogen transmission is increasingly implicated (e.g., Fisher and Garner 2007; Picco and Collins 2008; Walker et al. 2008; Schloegel et al. 2009; Auliya et al. 2016; Martel et al. 2013, 2014; Fisher et al. 2012; Nguyen et al. 2017; O’Hanlon et al. 2018). Preventing the novel introductions of emerging infectious diseases is of paramount importance (Gray et al. 2015; Grant et al. 2016), as once they gain a foothold, they can be “essentially unstoppable” (Fisher et al. 2012). In order to minimize anthropogenic influences on disease dynamics, biosecurity procedures and decision-support systems for biosecurity prioritization have been developed. In general, such procedures for herpetofaunal emerging infectious diseases have been framed relative to the stages of pathogen emergence (pre-arrival, invasion front, epidemic, and establishment: e.g., Garner et al. 2016; Grant et al. 2017) as well as the intertwining contexts of herpetological research, natural resource management activities, integrated biodiversity conservation practices, and the human dimension of transmission of novel pathogens, (e.g., Gray et al. 2018; More et al. 2018).

Herpetological Review↗

Coordinated bird monitoring: Technical recommendations for military lands

The Department of Defense (DoD) is subject to several rules and regulations establishing responsibilities for monitoring migratory birds. The Sikes Act requires all military installations with significant natural resources to prepare and implement Integrated Natural Resources Management Plans (INRMPs). These plans guide the conservation and long-term management of natural resources on military lands in a manner that is compatible with and sustains the military mission. An INRMP also supports compliance with all legal requirements and guides the military in fulfilling its obligation to be a good steward of public land.The management and conservation of migratory birds is addressed in installation INRMPs. The National Environmental Policy Act (NEPA) requires federal agencies to evaluate and disclose the potential environmental impacts of their proposed actions. More recently, DoD signed an MOU (http://www.dodpif.org/downloads/EO13186_MOU-DoD.pdf) for migratory birds, under Executive Order 13186, with the US Fish and Wildlife Service (USFWS) in July 2006 and a Migratory Bird Rule (http://www.dodpif.org/downloads/MigBirdFINALRule_FRFeb2007.pdf) was passed by Congress in February 2007. The Migratory Bird Rule addresses the potential impacts of military readiness activities on populations of migratory birds and establishes a process to implement conservation measures if and when a military readiness activity is expected to have a significant adverse impact on a population of migratory bird species (as determined through the NEPA process). The MOU states that for nonmilitary readiness activities, prior to initiating any activity likely to affect populations of migratory birds DoD shall (1) identify the migratory bird species likely to occur in the area of the proposed action and determine if any species of concern could be affected by the activity, and (2) assess and document, using NEPA when applicable, the effect of the proposed action on species of concern. By following these procedures, DoD will minimize the possibility for a proposed action to unintentionally take migratory birds at a level that would violate any of the migratory bird treaties and potentially impact mission activities. In addition, implementing conservation and monitoring programs for migratory birds supports the ecosystem integrity necessary to sustain DoD's natural resources for the military mission.Non-compliance with the procedural requirements of the MBTA could result in a private party lawsuit under the Administrative Procedures Act (APA). A lawsuit filed under APA involving a Navy bombing range is the basis for a court ruling that unintentional take of migratory birds applies to federal actions. Ensuring the necessary data is available to adequately assess impacts of a proposed action will help avoid lawsuits or help ensure such lawsuits have no grounds. The data gathered in a bird monitoring program will provide the best scientific data available to assess the expected impacts of a proposed action on migratory bird species through the NEPA process. This report presents recommendations developed by the U.S. Geological Survey (USGS) for the Department of Defense (DoD) on establishing a "Coordinated Bird Monitoring (CBM) Plan." The CBM Plan is intended to ensure that DoD meets its conservation and regulatory responsibilities for monitoring birds (Chapter 1). The report relies heavily on recommendations in the report, "Opportunities for improving avian monitoring" (http://www.nabci-us.org/aboutnabci/monitoringreportfinal0307.pdf), by the U.S. North American Bird Conservation Initiative (U.S. NABCI Monitoring Subcommittee, 2007) and on a review of 358 current DoD bird monitoring programs carried out as part of this project (Chapter 2). This report contains 12 recommendations which, if followed, would result in a comprehensive, efficient, and useful approach to bird monitoring. The recommendations are based on the entire report but are presented together at the end of Chapter 1. DoD has agreed to consider implementing these recommendations; however, final decisions will be based upon such factors as the availability of resources and military mission considerations. These recommendations from USGS can be summarized into 6 major themes: A major report on monitoring was released in 2007 by the U.S. North American Bird Conservation Initiative (http://www.nabci-us.org/main2.html). DoD can be consistent with this report by establishing policy that monitoring will be explicitly acknowledged as an integral element of bird management and conservation (Recommendation 1). The design of monitoring and assessment programs for birds should include the following steps: Preparation of a document describing the program's goals, objectives, and methods similar to a format we provide (Recommendation 2, Chapter 4). Selection of field methods using an "expert system" developed in this project (Recommendation 3, Chapter 5) or another well-documented system. Preparation and storage of metadata describing the monitoring program in the Natural Resources Monitoring Partnership (NRMP), and other appropriate databases Recommendation 4, Chapter 6). Entry of the survey data using eBird (http://ebird.org/content/dod) or the Coordinated Bird Monitoring Database (CBMD) and long-term storage of the data in the CBMD and the Avian Knowledge Network (AKN; Recommendation 5, Chapter 6; http://www.avianknowledge.net/). Submission of major results from the monitoring program for publication in a peer reviewed journal (Recommendation 6). The DoD Legacy Resource Management Program (Legacy; https://www.dodlegacy.org), Environmental Security Technology Certification Program (ESTCP; http://www.serdp.org/), and Strategic Environmental Research and Development Program (SERDP; http://www.serdp.org/) should be encouraged to continue their significant contributions to the foundations of bird monitoring (Recommendation 7, Chapters 1 and 3). Appropriate monitoring should be conducted to identify species of concern on installations. A year-round, one-time survey of birds on installations with habitat for migratory birds would provide the most information to assist compliance with the MOU, the Final Rule, and the NEPA analyses of proposed actions. However, less intensive survey efforts can still be conducted to yield useful information. We describe how various levels of survey effort might be organized and conducted. In addition, continuing surveys, as feasible, would further assist in documenting effects of military readiness and non-readiness activities on species of concern (SOC) (Recommendation 8, Chapter 7). Participation in well-designed, large-scale surveys [(e.g., North American Breeding Bird Survey (BBS; http://www.pwrc.usgs.gov/bbs/), Monitoring Avian Productivity and Survivorship (MAPS; http://www.birdpop.org/maps.htm)] on land that DoD manages or on lands where the results will be of high interest to DoD, will provide DoD and other NABCI members with information important to bird conservation (Recommendation 9, Chapter 8). Review and implementation of the CBM Plan should involve both higher level management and installation-level natural resources managers (Recommendation 11), be implemented through cooperative partnerships (Recommendation 12), and be followed on U.S territory lands and Army Corps of Engineers projects (Recommendation 10).Additional recommendations that pertain to implementing the DoD CBM Plan are discussed in Chapter 9.

Open-File Report↗

Ecology and biology of paddlefish in North America: historical perspectives, management approaches, and research priorities

Paddlefish ( Polyodon spathula , Polyodontidae)are large, mostly-riverine fish that once were abundant in medium- to large-sized river systems throughout much of the central United States. Concern for paddlefish populations has grown from a regional fisheries issue to one of national importance for the United States. In 1989, the U.S. Fish and Wildlife Service (USFWS) was petitioned to list paddlefish as a federally threatened species under the Endangered Species Act. The petition was not granted, primarily because of a lack of empirical data on paddlefish population size, age structure, growth, or harvest rates across the present 22-state range. Nonetheless, concern for paddlefish populations prompted the USFWS to recommend that paddlefish be protected through the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The addition of paddlefish to Appendix II of CITES, which was approved in March 1992, provides a mechanism to curtail illegal trade in paddlefish and their parts and supports a variety of conservation plans. Paddlefish populations have been negatively affected by overharvest, river modifications, and pollution, but the paddlefish still occupies much of its historic range and most extant populations seem to be stable. Although many facets of paddlefish biology and ecology are well understood, the lack of information on larval and juvenile ecology, mechanisms that determine recruitment, population size and vital rates, interjurisdictional movements, and the effects of anthropogenic activities present significant obstacles for managing paddlefish populations. Questions about the size and structure of local populations, and how such populations are affected by navigation traffic, dams, and pollution are regarded as medium priority areas for future research. The availability of suitable spawning habitat and overall reproductive success in impounded rivers are unknown and represent critical areas for future research. Research on reproductive and recruitment success in impounded rivers have significant implications for managing paddlefish, as rivers are modified further for human use.

Reviews in Fish Biology and Fisheries↗