Stratus Consulting

Boulder City, CO, United States

Stratus Consulting

Boulder City, CO, United States
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Kearns C.A.,University of Colorado at Boulder | Oliveras D.M.,University of Colorado at Boulder | Lay C.R.,Stratus Consulting
Journal of Insect Conservation | Year: 2017

Bumble bees are important pollinators of native flowers and crop plants. Consequently, declines in bumble bee populations in many regions around the globe are cause for concern. We monitored abundance of 22 bumble bee species at multiple elevations over 5 years in Boulder County, Colorado. While no declines in abundance of any species were apparent over the course of the study, such a finding does not preclude prior declines in abundance. This study provides current baseline abundance data that can be used for future monitoring projects. © 2017 Springer International Publishing Switzerland

Lew D.K.,University of California at Davis | Lew D.K.,University of Washington | Layton D.D.F.,University of Washington | Rowe R.D.,Stratus Consulting
Marine Resource Economics | Year: 2010

This article presents results from a stated preference survey of U.S. households intended to value the public's preferences for enhancements to the protection of the western stock of Steller sea lions, which is listed as endangered under the Endangered Species Act. To account for the uncertainty of future populations under current programs without additional protection efforts, three survey versions were implemented that each present different, yet plausible, baseline futures for Steiler sea lions. Stated preference choice experiment data from each survey are analyzed using repeated, rank ordered random parameters logit models, and welfare estimates are calculated and compared for each baseline for a variety of possible improvements. The willingness to pay (WTP) results reflect positive, but diminishing, marginal utility for improvements in the western stock population, regardless of baseline future: WTP increases for population improvements until the population greatly exceeds the current population, at which point the WTP for additional improvements levels off. Similarly, as would be expected, WTP for improvements to the western stock population decreases as the future baseline population forecast improves. Copyright © 2010 MRE Foundation, Inc.

Chen C.Y.,Dartmouth College | Borsuk M.E.,Dartmouth College | Bugge D.M.,Dartmouth College | Hollweg T.,Stratus Consulting | And 4 more authors.
PLoS ONE | Year: 2014

Methylmercury (MeHg) is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine). MeHg concentrations in water column particulate material, but not in sediments, were predictive of MeHg concentrations in fish (killifish and Atlantic silversides). Moreover, MeHg concentrations were higher in pelagic fauna than in benthic-feeding fauna suggesting that MeHg delivery to the water column from methylation sites from within or outside of the estuary may be an important driver of MeHg bioaccumulation in estuarine pelagic food webs. In contrast, bulk sediment MeHg concentrations were only predictive of concentrations of MeHg in the infaunal worms. Our results across a broad gradient of sites demonstrate that the pathways of MeHg to lower trophic level estuarine organisms are distinctly different between benthic deposit feeders and forage fish. Thus, even in systems with contaminated sediments, transfer of MeHg into estuarine food webs maybe driven more by the efficiency of processes that determine MeHg input and bioavailability in the water column. © 2014 Chen et al.

Morlando S.,Stratus Consulting | Schmidt S.J.,Union College at Schenectady | Logiudice K.,Union College at Schenectady
Restoration Ecology | Year: 2012

Habitat restoration is costly and it is often necessary to justify the costs with evidence of benefits to society. These benefits are difficult to quantify because they are measured in terms of ecosystem services rather than currency. This paper introduces a somewhat novel restoration-related ecosystem service, a reduction in the risk of tick-borne disease, and incorporates it into a cost/benefit analysis of the restoration of a rare habitat. We use a cost-of-illness study to calculate the costs averted by preventing Lyme disease (LD), and a contingent-valuation survey to estimate the benefit of biodiversity protection. The restoration, removal of an invasive tree, reduced the risk of LD by approximately 98%. Cost-of-illness studies show that the restoration would be financially justifiable if it averted 75 cases of LD per year. Given the local LD rate and the visitation rate to the preserve, the habitat restoration can plausibly be justified solely on the benefit of LD cases averted. However, as we do not know how many cases of LD are contracted in the preserve, we also establish the perceived value of protecting biodiversity in a contingent-valuation survey. Results show that residents were willing to pay a significant fraction of the net cost of restoration to protect biodiversity. When these benefits are taken into account, the number of cases of disease that must be averted to justify remediation is reduced. This exercise spotlights an underappreciated ecosystem service that, when appropriate, can help establish the cost effectiveness of restoration. © 2011 Society for Ecological Restoration International.

Wallace B.P.,Stratus Consulting | Wallace B.P.,Duke University | Schumacher J.,Southwest Fisheries Science Center | Seminoff J.A.,Southwest Fisheries Science Center | James M.C.,Canadian Department of Fisheries and Oceans
Marine Biology | Year: 2014

Understanding the causes and consequences of variability in trophic status is important for interpreting population dynamics and for identifying important habitats for protected species like marine turtles. In the northwest Atlantic Ocean, many leatherback turtles (Dermochelys coriacea) from distinct breeding stocks throughout the Wider Caribbean region migrate to Canadian waters seasonally to feed, but their trophic status during the migratory and breeding cycle and its implications have not yet been described. In this study, we used stable carbon and nitrogen isotope analyses of bulk skin to characterize the trophic status of leatherbacks in Atlantic Canadian waters by identifying trophic patterns among turtles and the factors influencing those patterns. δ15N values of adult males and females were significantly higher than those of turtles of unknown gender (i.e., presumed to be subadults), and δ15N increased significantly with body size. We found no significant differences among average stable isotope values of turtles according to breeding stock origin. Significant inter-annual variation in δ15N among cohorts probably reflects broad-scale oceanographic variability that drives fluctuations in stable isotope values of nutrient sources transferred through several trophic positions to leatherbacks, variation in baseline isotope values among different overwintering habitats used by leatherbacks, or a combination of both. Our results demonstrate that understanding effects of demographic and physiological factors, as well as oceanographic conditions, on trophic status is key to explaining observed patterns in population dynamics and for identifying important habitats for widely distributed, long-lived species like leatherbacks. © 2014 Springer-Verlag Berlin Heidelberg.

Bierbaum R.,University of Michigan | Smith J.B.,Stratus Consulting | Lee A.,Chevron | Blair M.,American Cancer Society | And 8 more authors.
Mitigation and Adaptation Strategies for Global Change | Year: 2013

We reviewed existing and planned adaptation activities of federal, tribal, state, and local governments and the private sector in the United States (U.S.) to understand what types of adaptation activities are underway across different sectors and scales throughout the country. Primary sources of review included material officially submitted for consideration in the upcoming 2013 U.S. National Climate Assessment and supplemental peer-reviewed and grey literature. Although substantial adaptation planning is occurring in various sectors, levels of government, and the private sector, few measures have been implemented and even fewer have been evaluated. Most adaptation actions to date appear to be incremental changes, not the transformational changes that may be needed in certain cases to adapt to significant changes in climate. While there appear to be no one-size-fits-all adaptations, there are similarities in approaches across scales and sectors, including mainstreaming climate considerations into existing policies and plans, and pursuing no- and low-regrets strategies. Despite the positive momentum in recent years, barriers to implementation still impede action in all sectors and across scales. The most significant barriers include lack of funding, policy and institutional constraints, and difficulty in anticipating climate change given the current state of information on change. However, the practice of adaptation can advance through learning by doing, stakeholder engagements (including "listening sessions"), and sharing of best practices. Efforts to advance adaptation across the U.S. and globally will necessitate the reduction or elimination of barriers, the enhancement of information and best practice sharing mechanisms, and the creation of comprehensive adaptation evaluation metrics. © The Author(s) 2012.

Morris J.M.,Stratus Consulting | Jin S.,Fort Technologies | Jin S.,University of Wyoming
Journal of Hazardous Materials | Year: 2012

A sediment microbial fuel cell (MFC) was tested to determine if electron transfer from the anaerobic zone of contaminated sediments to the overlying aerobic water could facilitate an enhanced and aerobic equivalent degradation of total petroleum hydrocarbons (TPH). Results indicate that voltages as high as 190mV (2162mW/m 3) were achieved in a sediment MFC with an anode buried in sediments containing TPH concentrations at approximately 16,000mgkg -1. Additionally, after approximately 66 days, the TPH degradation rates were 2% and 24% in the open-circuit control sediment MFC and active sediment MFC, respectively. Therefore, it appears that applying MFC technology to contaminated sediments enhances natural biodegradation by nearly 12 fold. Additionally, a novel sediment MFC was designed to provide a cost-effective method of passive oxidation or indirect aerobic degradation of contaminants in an otherwise anaerobic environment. In addition, the use of a wicking air cathode in this study maintained dissolved oxygen concentrations 1-2mgl -1 higher than submerged cathodes, demonstrating that this technology can be applied to environments with either aerobic or anaerobic overlying water and an anaerobic matrix, such as shallow lagoon, ponds, and marshes, and groundwater. © 2012 Elsevier B.V.

Cullis J.,Auercon Formally Ninham Shand | Cullis J.,University of Colorado at Boulder | Strzepek K.,University of Colorado at Boulder | Tadross M.,University of Cape Town | And 4 more authors.
Climatic Change | Year: 2011

Incorporating climate change into water resource planning is crucial to ensuring sustainable growth and development. The aim of this study was to investigate how the proposed steps to incorporating climate change into project planning developed by USAID could be applied in practice using the town of Polokwane in northeastern South Africa as a case study. Two Regional Circulation Models (RCMs) and statistical downscaling from a range of General Circulation Models (GCMs) were used to produce a set of monthly climate scenarios for 2025 and 2050. These scenarios were used to estimate the impact on surface water runoff in the Olifants River catchment and the Letaba River catchment, and groundwater recharge in the Sand River Aquifer. The impact on the potential yields from the existing Flag Bashielo Dam and other proposed dams in the Olifants River catchment were determined using the Water Resources Yield Model (WRYM). The results of the analysis were discussed at a regional stakeholders workshop. The workshop participants concluded that the higher priority for now should be on water conservation and demand management (WCDM) and to consider a phased approach to developing additional storage capacity. The results of this study show that the six-stage process for incorporating climate change into resource planning can be applied in practice and that the potential threat of climate change can give emphasis to existing win-win approaches such as WCDM and phased implementation that should form part of any sustainable water resource planning approach. © 2010 Springer Science+Business Media B.V.

Kidson R.,University of California at Santa Cruz | Haddad B.,University of California at Santa Cruz | Zheng H.,University of Sydney | Kasower S.,Digital Transportation Corporation | Raucher R.,Stratus Consulting
Water Resources Management | Year: 2013

This paper considers the retail water provider's purchasing decision of a portfolio of permanent contracts from wholesalers with multiple volatile water sources. We consider the reliability of two contract types: (1) fixed annual quantities, and (2) an inflow harvest function with storage. Our four-reservoir case in Sydney (Australia) has cross-correlated inflow data. To accommodate multi-reservoir cross-correlation we adapt Portfolio Theory from finance to lognormal reservoir inflows, re-framing traditional storage theory from the wholesaler's optimal operating policy to the retailer's optimal purchasing policy. We find that Reliability improves with access to a source pool (cf. fixed quantities from separate sources), demonstrating the 'insurance effect', and the portfolio that minimises lognormal variance also minimises harvest (and thus environmental impact). Reform direction in Australian (and other international) water markets is towards multi-provider vertical disintegration, which may reduce pool opportunities and negate the insurance effect. We consider diminishing reliability returns as reservoir harvesting increases, and conclude a retail portfolio of permanent contracts from reservoirs, plus short-term contracts from alternative sources (either independently or negatively cross-correlated) efficiently secures high reliability. The challenge in incomplete water markets remains in encouraging and sustaining supply diversification that may only be needed aperiodically during extreme droughts. © 2013 Springer Science+Business Media Dordrecht.

Ebi K.L.,ClimAdapt LLC | Mills D.,Stratus Consulting
Wiley Interdisciplinary Reviews: Climate Change | Year: 2013

In temperate climates, mortality is higher in the winter than the summer. Most wintertime deaths are attributed to cardiovascular and respiratory disease, with hypothermia from extreme cold accounting for a negligible share of all recorded deaths. International and national assessments of the health risks of climate change often conclude that increased temperatures from climate change will likely reduce winter mortality. This article examines the support for this hypothesis. We find that although there is a physiological basis for increased cardiovascular and respiratory disease mortality during winter months, the limited evidence suggests cardiovascular disease mortality is only weakly associated with temperature. Although respiratory disease mortality shows a stronger seasonal relationship with colder temperatures, cold alone does not explain infection rates. Further, respiratory disease mortality is a relatively small proportion of winter deaths. Therefore, assuming no changes in acclimatization and the degree to which temperature-related deaths are prevented, climate change may alter the balance of deaths between winters and summers, but is unlikely to dramatically reduce overall winter mortality rates. © 2013 John Wiley & Sons, Ltd.

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