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At least 487 records · Page 27Linked to original sources

USGS2023

Assessment of potential recovery viability for Colorado Pikeminnow Ptychocheilus lucius in the Colorado River in Grand Canyon

Colorado Pikeminnow Ptychocheilus lucius, the Colorado River’s top native predatory fish, was historically distributed from the Gulf of California delta to the upper reaches of the Green, Colorado, and San Juan rivers in the Colorado River basin in the Southwestern US. In recent decades Colorado Pikeminnow population abundance has declined, primarily due to predation by warmwater nonnative fish and habitat modification following dam construction. Small, reproducing populations remain in the Green and upper Colorado rivers, but their current population trajectory is declining and the San Juan River population is maintained primarily through stocking. As such, establishment of an additional population could aid recovery efforts and increase the species’ resilience and population redundancy. The Colorado River in Grand Canyon once supported Colorado Pikeminnow, but until recently habitat suitability in this altered reach was considered low due to a depressed thermal regime and abundant nonnative predators. Climate change and ongoing drought has presented an opportunity to evaluate the feasibility of native fish restoration in a system where declining reservoir storage has led to warmer releases and re-emergence of riverine habitat. These changes in the physical attributes of the river have occurred in concert with a system-wide decline in nonnative predators. Conditions ten years ago were not compatible with reintroduction feasibility in Grand Canyon; however, due to rapidly changing conditions an expert Science Panel was convened to evaluate whether the physical and biological attributes of this reach could now support various life stages of Colorado Pikeminnow. Here, we report on the evaluation process and outcome from the Science Panel, which developed a science-based recommendation to the U.S. Fish and Wildlife Service on reintroduction feasibility. The Science Panel concluded that current habitat attributes in Grand Canyon could satisfy some, but perhaps not all, Colorado Pikeminnow life history requirements. This reach has the potential to support adult and sub-adult growth, foraging, migrations, and spawning, but low juvenile survival may limit recruitment. However, populations of other native species are successfully reproducing and increasing in western Grand Canyon, even in areas once considered suboptimal habitat. Should managers decide to move to the next phase of this process, actions such as experimental stocking and monitoring, telemetry studies, bioenergetics modeling, and laboratory-based research may provide additional information to further evaluate a potential reintroduction effort in this rapidly changing but highly altered system.

Arizona↗

USGS2024

Phenology forecasting models for detection and management of invasive annual grasses

Non-native annual grasses can dramatically alter fire frequency and reduce forage quality and biodiversity in the ecosystems they invade. Effective management techniques are needed to reduce these undesirable invasive species and maintain ecosystem services. Well-timed management strategies, such as grazing, that are applied when invasive grasses are active prior to native plants can control invasive species spread and reduce their impact; however, anticipating the timing of key phenological stages that are susceptible to management over vast landscapes is difficult, as the phenology of these species can vary greatly over time and space. To address this challenge, we created range-wide phenology forecasts for two problematic invasive annual grasses: cheatgrass ( Bromus tectorum ), and red brome ( Bromus rubens ). We tested a suite of 18 mechanistic phenology models using observations from monitoring experiments, volunteer science, herbarium records, timelapse camera imagery, and downscaled gridded climate data to identify the models that best predicted the dates of flowering and senescence of the two invasive grass species. We found that the timing of flowering and senescence of cheatgrass and red brome were best predicted by photothermal time models that had been adjusted for topography using gridded continuous heat-insolation load index values. Phenology forecasts based on these models can help managers make decisions about when to schedule management actions such as grazing to reduce undesirable invasive grasses and promote forage production, quality, and biodiversity in grasslands; to predict the timing of greatest fire risk after annual grasses dry out; and to select remote sensing imagery to accurately map invasive grasses across topographic and latitudinal gradients. These phenology models also have the potential to be operationalized for within-season or within-year decision support.

Ecosphere↗

USGS2025

Public support for puma reintroduction in the eastern United States

Pumas ( Puma concolor ) are among the species identified as having the potential to enhance ecosystem function. Previous research highlights sufficient ecological habitat to support pumas in the eastern United States; however, their reintroduction requires social and institutional support as well. To this end, we conducted research to assess attitudes about puma reintroduction among key constituencies like hunters, rural residents, and young people. We sampled 2756 respondents across seven states (Massachusetts, Maine, New Hampshire, New York, Pennsylvania, Vermont, and West Virginia). Ratios of strong support (for puma reintroduction) to strong opposition across states ranged from 4:1 to 13:1, and support outweighed opposition in every state. Our results contrasted with common assumptions that hunters, rural residents, and people who identify as politically conservative oppose carnivore conservation and reintroduction. We found marginal differences among categories of people, but overall little variation in support exhibited by different groups. People who identified very strongly as hunters were more supportive of reintroduction than those who did not identify as hunters at all. Taken together, the presence of quality habitat and support for puma restoration warrant further exploration. However, federal funding for state-based restoration efforts likely requires the inclusion of pumas in State Wildlife Action Plans (SWAPs), which are currently under a 10-year revision due to be published this year (2025).

Maine, Massachusetts, New Hampshire, New York, Pen↗

USGS2025

Estimating drivers and identifying uncertainties in smallmouth bass population dynamics in an invaded river network

Smallmouth bass ( Micropterus dolomieu ) is an important recreational sportfish and destructive non-native species when introduced into freshwater habitats. There is therefore a need to understand the drivers of, and uncertainties in, smallmouth bass population dynamics for various management objectives. We combined long-term smallmouth bass catch-effort and early life history data from a non-native population in the Green River sub-basin of the upper Colorado River to develop a demographic model that links interannual variability in environmental conditions to recruitment in three river reaches. We used the model to quantify how hydrology, river temperature, and exploitation drive smallmouth bass population dynamics. Early life stages were influenced by timing of hatching and discharge. Dispersal of age-0 fish and density-dependent dynamics were identified as primary sources of uncertainty. Determining the true nature of density-dependent dynamics is important, as the impact of exploitation-based management actions is dependent on the strengths of any density-dependent feedbacks. Our model provides a framework to predict smallmouth bass population responses to future climate conditions, reservoir operations, and exploitation levels.

Utah↗

USGS2017

Use of fish telemetry in rehabilitation planning, management, and monitoring in Areas of Concern in the Laurentian Great Lakes

Freshwater ecosystems provide many ecosystem services; however, they are often degraded as a result of human activity. To address ecosystem degradation in the Laurentian Great Lakes, Canada and the United States of America established the Great Lakes Water Quality Agreement (GLWQA). In 1987, 43 highly polluted and impacted areas were identified under the GLWQA as having one or more of 14 Beneficial Use Impairments (BUIs) to the physical and chemical habitat for fish, wildlife and humans, and were designated as Areas of Concern (AOC). Subnational jurisdictions combined with local stakeholders, with support from federal governments, developed plans to remediate and restore these sites. Biotelemetry (the tracking of animals using electronic tags) provides information on the spatial ecology of fish in the wild relevant to habitat management and stock assessment. Here, seven case studies are presented where biotelemetry data were directly incorporated within the AOC Remedial Action Plan (RAP) process. Specific applications include determining seasonal fish–habitat associations to inform habitat restoration plans, identifying the distribution of pollutant-indicator species to identify exposure risk to contamination sources, informing the development of fish passage facilities to enable fish to access fragmented upstream habitats, and assessing fish use of created or restored habitats. With growing capacity for fish biotelemetry research in the Great Lakes, we discuss the strengths and weaknesses of incorporating biotelemetry into AOC RAP processes to improve the science and practice of restoration and to facilitate the delisting of AOCs.

Great Lakes↗

USGS2022

Teams, networks, and networks of networks advancing our understanding and conservation of inland waters

Networks are defined as groups of interconnected people and things, and by this definition, networks play a major role in the science of inland waters. In this article, we bring the latest social network research to understand and improve inland waters science and conservation outcomes. What we found is that relationships matter. Different teams and networks have different objectives and lifespans. Consider this: Data collection networks may persist for decades, whereas knowledge-generating teams may exist only for months. The structure of connections in a network determines how easily information or resources can flow or pass through a network, which then influences the ability of the network to accomplish work like creating and applying new knowledge, integrating knowledge across fields, or coordinating collective action. When independent networks designed around different purposes become connected to achieve new goals, a network of networks is formed, where each layer is a unique network defined by social, geographic, and temporal boundaries and distinct types of connections. This structure has a lot of potential for transformative work, but is especially susceptible to failure if one of the cross-network connections fails. From the smallest of inland waters research teams to the largest, multi-institutional, international collaborations, an understanding of how the connections between people are created and maintained can be used to set up conditions for success.

Book chapter↗

USGS2012

Applications of science and engineering to quantify and control the Deepwater Horizon oil spill

The unprecedented engagement of scientists from government, academia, and industry enabled multiple unanticipated and unique problems to be addressed during the Deepwater Horizon oil spill. During the months between the initial blowout on April 20, 2010, and the final well kill on September 19, 2010, researchers prepared options, analyses of tradeoffs, assessments, and calculations of uncertainties associated with the flow rate of the well, well shut in, killing the well, and determination of the location of oil released into the environment. This information was used in near real time by the National Incident Commander and other government decision-makers. It increased transparency into BP’s proposed actions and gave the government confidence that, at each stage proposed, courses of action had been thoroughly vetted to reduce risk to human life and the environment and improve chances of success.

Alabama;Florida;Louisiana;Mississippi;Texas↗

USGS2019

Slough evolution and legacy mercury remobilization induced by wetland restoration in South San Francisco Bay

Coastal wetlands have a long history of degradation and destruction due to human development. Now recognized as one of the most productive ecosystems in the world, substantial efforts are being made to restore this critical habitat. While wetland restoration efforts are generally viewed as beneficial in terms of providing wildlife habitat and flood control, they are often accompanied by dramatic physical and chemical changes that may result in unintended consequences, which are rarely studied. Alviso Slough, a tidal slough in South San Francisco Bay, California, is the site of an ongoing effort to restore former salt-production ponds to intertidal marsh habitat. Restoration is complicated by the fact that (1) the ponds undergoing restoration are severely subsided and (2) subsurface sediments within the slough and surrounding ponds are contaminated with legacy mercury deposits. Due to concerns regarding mercury remobilization, restoration has proceeded in a cautious, methodical manner. To assess the amount of legacy mercury remobilized since restoration began, we developed a technique of combining high-resolution, biannual measurements of bathymetric scour with mercury concentration measurements from sediment cores. We estimate that 52 kg (±3) of mercury was remobilized in the 6 years since restoration began. Net bathymetric change analyses revealed seasonal trends of peak erosion during the winter months and little to no net change during summer months. Our analyses provide crucial insight on the spatial and temporal scales of geomorphic evolution within a tidal slough resulting from both natural (seasonal) variability and restoration actions. The technique presented here could be applied to other study sites and various sediment-associated contaminants of concern to aid in the design and management of restoration projects aiming to minimize negative impacts from legacy contaminants.

California↗

USGS2018

Increasing chloride in rivers of the conterminous U.S. and linkages to potential corrosivity and lead action level exceedances in drinking water

Corrosion in water-distribution systems is a costly problem and controlling corrosion is a primary focus of efforts to reduce lead (Pb) and copper (Cu) in tap water. High chloride concentrations can increase the tendency of water to cause corrosion in distribution systems. The effects of chloride are also expressed in several indices commonly used to describe the potential corrosivity of water, the chloride-sulfate mass ratio (CSMR) and the Larson Ratio (LR). Elevated CSMR has been linked to the galvanic corrosion of Pb whereas LR is indicative of the corrosivity of water to iron and steel. Despite the known importance of chloride, CSMR, and LR to the potential corrosivity of water, monitoring of seasonal and interannual changes in these parameters is not common among water purveyors. We analyzed long-term trends (1992–2012) and the current status (2010–2015) of chloride, CSMR, and LR in order to investigate the short and long-term temporal variability in potential corrosivity of US streams and rivers. Among all sites in the trend analyses, chloride, CSMR, and LR increased slightly, with median changes of 0.9 mg L − 1 , 0.08, and 0.01, respectively. However, urban-dominated sites had much larger increases, 46.9 mg L − 1 , 2.50, and 0.53, respectively. Median CSMR and LR in urban streams (4.01 and 1.34, respectively) greatly exceeded thresholds found to cause corrosion in water distribution systems (0.5 and 0.3, respectively). Urbanization was strongly correlated with elevated chloride, CSMR, and LR, especially in the most snow-affected areas in the study, which are most likely to use road salt. The probability of Pb action-level exceedances (ALEs) in drinking water facilities increased along with raw surface water CSMR, indicating a statistical connection between surface water chemistry and corrosion in drinking water facilities. Optimal corrosion controlwill require monitoring of critical constituents reflecting the potential corrosivity in surface waters.

Science of the Total Environment↗

USGS2024

Accuracy, accessibility, and institutional capacity shape the utility of habitat models for managing and conserving rare plants on western public lands

Public lands are often managed for multiple uses ranging from energy development to rare plant conservation. Habitat models can help land managers assess and mitigate potential effects of projects on rare plants, but it is unclear how models are currently being used. Our goal was to better understand how staff in the Bureau of Land Management currently use habitat models to inform their decisions, and perceived challenges and benefits associated with that use. We first examined litigation documents to determine whether the agency has been challenged on its use of data for rare plants and found no relevant legal challenges. Second, we analyzed model use in National Environmental Policy Act (NEPA) documents and found no clear citations of habitat models. Finally, we conducted interviews with agency staff who analyze potential effects of proposed actions on rare plants in NEPA documents. The primary challenges interviewees faced in using models related to data organization and access, model quality and accuracy, and institutional capacity. Interviewees believed models could be used more to inform decisions and actions to conserve rare plants and rare plant habitat on public lands and recommended improving staff access to models, creating models for additional species, and addressing staffing limitations.

Arizona, California, Colorado, New Mexico, Utah, W↗

USGS2008

Hazard information management during the autumn 2004 reawakening of Mount St. Helens volcano, Washington

The 2004 reawakening of Mount St. Helens quickly caught the attention of government agencies as well as the international news media and the public. Immediate concerns focused on a repeat of the catastrophic landslide and blast event of May 18, 1980, which remains a vivid memory for many individuals. Within several days of the onset of accelerating seismicity, media inquiries increased exponentially. Personnel at the U.S. Geological Survey, the Pacific Northwest Seismic Network, and the Gifford Pinchot National Forest soon handled hundreds of press inquiries and held several press briefings per day. About one week into the event, a Joint Information Center was established to help maintain a consistent hazard message and to provide a centralized information source about volcanic activity, hazards, area closures, and media briefings. Scientists, public-affairs specialists, and personnel from emergency-management, health, public-safety, and land-management agencies answered phones, helped in press briefings and interviews, and managed media access to colleagues working on science and safety issues. For scientists, in addition to managing the cycle of daily fieldwork, challenges included (1) balancing accurate interpretations of data under crisis conditions with the need to share information quickly, (2) articulating uncertainties for a variety of volcanic scenarios, (3) minimizing scientific jargon, and (4) frequently updating and effectively distributing talking points. Success of hazard information management during a volcanic crisis depends largely on scientists’ clarity of communication and thorough preplanning among interagency partners. All parties must commit to after-action evaluation and improvement of communication plans, incorporating lessons learned during each event.

Washington↗

USGS2010

Wyoming Landscape Conservation Initiative Science and Management Workshop Proceedings, May 12-14, 2009, Laramie, Wyoming

The U.S. Geological Survey (USGS) hosted the second Wyoming Landscape Conservation Initiative (WLCI) Science and Management Workshop at the University of Wyoming Conference Center and Hilton Garden Inn on May 12, 13, and 14, 2009, in Laramie, Wyo. The workshop focused on six topics seen as relevant to ongoing WLCI science and management activities: mapping and modeling resources for decisionmaking; data information and management; fish and wildlife research; changing landscapes; monitoring; and reclamation and offsite mitigation. Panelists gave presentations on ongoing research in these six areas during plenary sessions followed by audience discussions. Three breakout groups focused on discussing wildlife, reclamation, and monitoring. Throughout the plenary sessions, audience discussions, and breakout groups, several needs were repeatedly emphasized by panelists and workshop participants: developing a conservation plan and identifying priority areas and species for conservation actions; gaining a deeper understanding of sagebrush ecology; identifying thresholds for wildlife that can be used to create an 'early warning system' for managers; continuing to collect basic data across the landscape; facilitating even greater communication and partnership across agencies and between scientists and land managers; and engaging proactively in understanding new changes on the landscape such as wind energy development and climate change. Detailed proceedings from the workshop are captured and summarized in this report.

Scientific Investigations Report↗

USGS2023

Editorial: Volcanic forecasting, crisis management, and risk communication

Volcanic eruptions intermittently punctuate periods of repose at volcanic centers and fields. Forecasting the timing, style, distribution, and magnitude of these eruptions is difficult, because eruptive activity varies over time, commonly in an irregular way. Furthermore, the impacts of eruptions can include loss of lives, property damage, and social and economic disturbance, where every eruption produces different impacts. Mitigation of volcanic risk is therefore complex, requiring community action that is aided by preparedness actions of emergency managers, stakeholders, community leaders, and individuals, and by timely delivery and reception of hazard information during a crisis. This Research Topic addresses efforts to understand complexities in these relations dealing with volcanic unrest, eruptions, and eruption impacts. Research Topic range from eruption forecasting (Wild et al.; Christophersen et al.; Bernard et al.) and volcanic hazard assessment (Mead et al.) to risk communication and action (Martinez-Villegas et al.; Todesco et al.; Graham et al.; Bernard et al.) prior to and during volcanic crises. The studies use various methodologies and approaches, touching on various parts of the integrated, multi-partner systems that exist to improve risk mitigation.

Frontiers in Earth Science↗

USGS2022

Assessing the distribution and habitat needs of the Least Darter and sympatric species of the Ozark and Arbuckle Mountain ecoregions

Limited information is known about factors driving the distribution of Least Darter in Oklahaoma. The Least Darter occurs in the Ozark Highland and Arbuckle Uplift ecoregions of Oklahoma which represent the southern extent of its range. Least Darter was historically recorded in Oklahoma from groundwater-fed streams. Our study objectives were to determine the distribution of Least Darter and a subset of congeners across the two ecoregions of Oklahoma and assess factors driving patch occupancy of Least Darter at a fine spatial scale. We used temporally replicated snorkel surveys conducted in July through October 2018-2019 to determine occupany by Least Darter. We snorkeled and seined for four species in each reach including two life stages of Smallmouth Bass (subadult and adult). We sampled 153 sites (i.e., riffle-pool complexes) nested within 61 stream reaches (i.e., 200-500-m long) in the Arbuckle Uplift and Ozark Highland ecoregions. Detection probability was similar between ecoregions. Least Darter was detected at more sites when snorkeling compared to seining (24 versus 18). Smallmouth Bass, Redspot Chub and Southern Redbelly Dace were typically 2-3 times more likely to be detected by snorkeling than by seining. We found relationships between occupancy and habitat parameters that were both shared among species but also species-specific. Least Darter occurrence probability in the Ozark Highlands was lower than in the Arbuckle Uplift. Occurrence probability was higher for subadult Smallmouth Bass and Southern Redbelly Dace in 2018 compared to 2019. Occurrence probabilities of both Least Darter and Southern Redbelly Dace were higher in cooler habitat patches. Southern Redbelly Dace was negatively associated with a higher proportion of pool habitat across a reach. Lastly, subadult Smallmouth Bass and Redspot Chub were more likely to occur in deeper pools and in larger streams (i.e., drainage area). We sampled one study reach (~150-m long with shallow riffles or a waterfall on each end) in the Arbuckle Uplift (winter and summer sampling) and Ozark Highland (winter sampling) ecoregions to determine fine-scale habitat selection during the thermally harsh seasons. We developed transects across the reaches to quantify depth, velocity, substrate, cover and water temperature. We found Least Darter used higher water column velocities and shallower water depths with little vegetation during the winter. The average water depth used was similar during summer and winter (~ 20 cm deep). Least Darter used denser vegetation during the summer and tended to avoid coarse substrates in both seasons. If the conservation of Least Darter is a management goal, actions to mitigate increasing stream water temperatures (e.g., protection of springs and riparian corridors) and protecting stream morphologies that facilitate species separations (i.e., allow for a wide range of water depth and velocities) may be beneficial (e.g., fencing cattle from streams, promoting natural bankful flows during spring)

Oklahoma↗

USGS2008

USGS Workshop on Scientific Aspects of a Long-Term Experimental Plan for Glen Canyon Dam, April 10-11, 2007, Flagstaff, Arizona

Executive Summary Glen Canyon Dam is located in the lower reaches of Glen Canyon National Recreation Area on the Colorado River, approximately 15 miles upriver from Grand Canyon National Park (fig. 1). In 1992, Congress passed and the President signed into law the Grand Canyon Protection Act (GCPA; title XVIII, sec. 1801?1809, of Public Law 102-575), which seeks ?to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established.? The Glen Canyon Dam Adaptive Management Program (GCDAMP) was implemented as a result of the 1996 Record of Decision on the Operation of Glen Canyon Dam Final Environmental Impact Statement to ensure that the primary mandate of the GCPA is met through advances in information and resources management (U.S. Department of the Interior, 1995). On November 3, 2006, the Bureau of Reclamation (Reclamation) announced it would develop a long-term experimental plan environmental impact statement (LTEP EIS) for operational activities at Glen Canyon Dam and other management actions on the Colorado River. The purpose of the long-term experimental plan is twofold: (1) to increase the scientific understanding of the ecosystem and (2) to improve and protect important downstream resources. The proposed plan would implement a structured, longterm program of experimentation to include dam operations, potential modifications to Glen Canyon Dam intake structures, and other management actions such as removal of nonnative fish species. The development of the long-term experimental plan continues efforts begun by the GCDAMP to protect resources downstream of Glen Canyon Dam, including Grand Canyon, through adaptive management and scientific experimentation. The LTEP EIS will rely on the extensive scientific studies that have been undertaken as part of the adaptive management program by the U.S. Geological Survey?s (USGS) Grand Canyon Monitoring and Research Center (GCMRC), one of the four research stations within the USGS Southwest Biological Science Center. On April 10 and 11, 2007, at the behest of Reclamation, the GCMRC convened a workshop with scientific experts to identify one or more scientifically credible, long-term experimental options for Reclamation to consider for the LTEP EIS that would be consistent with the purpose and need for the plan. Workshop participants included government, academic, and private scientists with broad experience in the Colorado River in Grand Canyon and regulated rivers around the world. Resource managers and GCDAMP participants were also present on the second day of the workshop. In advance of the workshop, Reclamation and LTEP EIS cooperating agencies identified 14 core scientific questions. Workshop participants were asked to consider how proposed options would address these questions, which fall primarily into four areas: (1) conservation of endangered humpback chub (Gila cypha) and other high-priority biological resources, (2) conservation of sediment resources, (3) enhancement of recreational resources, and (4) preservation of cultural resources. A secondary objective of the workshop was the evaluation of four long-term experimental options developed by the GCDAMP Science Planning Group (SPG) (appendix B). The flow and nonflow treatments called for in the four experimental options were an important starting point for workshop discussions. At the beginning of the workshop, participants were provided with the final LTEP EIS scoping report prepared by Reclamation. Participants were also advised that Reclamation had committed to ?make every effortEto ensure that a new population of humpback chub is established in the mainstem or one or more of the tributaries within Grand Canyon? in the 1995 Operation of Glen Canyon Dam Final Environmental Impact Statement (U.S. Department of the Interior, 1995). This decision was consistent with the U.S. Fish and Wildlife Service?s 1995 bi

Open-File Report↗

USGS2013

A scenario and forecast model for Gulf of Mexico hypoxic area and volume

For almost three decades, the relative size of the hypoxic region on the Louisiana-Texas continental shelf has drawn scientific and policy attention. During that time, both simple and complex models have been used to explore hypoxia dynamics and to provide management guidance relating the size of the hypoxic zone to key drivers. Throughout much of that development, analyses had to accommodate an apparent change in hypoxic sensitivity to loads and often cull observations due to anomalous meteorological conditions. Here, we describe an adaptation of our earlier, simple biophysical model, calibrated to revised hypoxic area estimates and new hypoxic volume estimates through Bayesian estimation. This application eliminates the need to cull observations and provides revised hypoxic extent estimates with uncertainties, corresponding to different nutrient loading reduction scenarios. We compare guidance from this model application, suggesting an approximately 62% nutrient loading reduction is required to reduce Gulf hypoxia to the Action Plan goal of 5,000 km 2 , to that of previous applications. In addition, we describe for the first time, the corresponding response of hypoxic volume. We also analyze model results to test for increasing system sensitivity to hypoxia formation, but find no strong evidence of such change.

Environmental Science & Technology↗

USGS2020

Category count models for adaptive management of metapopulations: Case study of an imperiled salamander

Managing spatially structured populations of imperiled species presents many challenges. Spatial structure can make it difficult to predict population responses to potential recovery activities, and learning through experimentation may not be advised if it could harm threatened populations. Adaptive management provides an appealing framework when experimentation is considered too risky or time consuming; we used such an approach for imperiled flatwoods salamanders at a Florida wildlife refuge. We represented this metapopulation with category count models and used stochastic dynamic programming to identify optimal decision policies that weighed trade‐offs between metapopulation persistence and management costs. We defined possible wetland categories in terms of habitat suitability and occupancy, specified category‐specific management actions, and identified transition probabilities via expert elicitation for two management strategies: “future” status quo (FSQ; frequent growing‐season burns) and extra management actions (EMA; restoration, translocation, head‐starting). We simulated metapopulation dynamics using the resulting optimal management policy and found that under model FSQ, occupancy steadily declined over time, indicating that populations would rapidly become extirpated; with model EMA, occupancy remained stable, suggesting that populations would persist only if additional actions are applied and are effective. This approach can be used to identify optimal solutions while accounting for uncertainty and considering both habitat and population dynamics, and to help managers make conservation decisions for populations at imminent risk of extinction.

Florida↗

USGS2010

Proceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona

Since the 1980s, four major science and restoration programs have been developed for the Colorado River Basin to address primarily the conservation of native fish and other wildlife pursuant to the Endangered Species Act (ESA): (1) Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin (commonly called the Upper Colorado River Endangered Fish Recovery Program) (1988); (2) San Juan River Basin Recovery Implementation Program (1992); (3) Glen Canyon Dam Adaptive Management Program (1997); and (4) Lower Colorado River Multi-Species Conservation Program (2005). Today, these four programs, the efforts of which span the length of the Colorado River, have an increasingly important influence on water management and resource conservation in the basin. The four efforts involve scores of State, Federal, and local agencies; Native American Tribes; and diverse stakeholder representatives. The programs have many commonalities, including similar and overlapping goals and objectives; comparable resources and threats to those resources; and common monitoring, research, and restoration strategies. In spite of their commonalities, until recently there had been no formal opportunity for information exchange among the programs. To address this situation, the U.S. Geological Survey (USGS) worked in coordination with the four programs and numerous Federal and State agencies to organize the first Colorado River Basin Science and Resource Management Symposium, which took place in Scottsdale, AZ, in November 2008. The symposium's primary purpose was to promote an exchange of information on research and management activities related to the restoration and conservation of the Colorado River and its major tributaries. A total of 283 managers, scientists, and stakeholders attended the 3-day symposium, which included 87 presentations and 27 posters. The symposium featured plenary talks by experts on a variety of topics, including overviews of the four restoration programs, water-management actions aimed at restoring native fish habitat, climate change, assessments of the status of native and nonnative fish populations, and Native American perspectives. Intermixed with plenary talks were four concurrent technical sessions that addressed the following important topics: (1) effects of dam and reservoir operations on downstream physical and biological resources; (2) native fish propagation and genetic management and associated challenges in co-managing native and nonnative fish in the Colorado River; (3) monitoring program design, case studies, and links to management; and (4) riparian system restoration, monitoring, and exotic species control efforts.

Scientific Investigations Report↗