scholarly journals Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada

2021 ◽  
Vol 16 (12) ◽  
pp. 124024
Author(s):  
Lauren A MacDonald ◽  
Kevin W Turner ◽  
Ian McDonald ◽  
Mitchell L Kay ◽  
Roland I Hall ◽  
...  

Abstract Lake-rich northern permafrost landscapes are sensitive to changing climate conditions, but ability to track real-time and potentially multiple hydrological responses (e.g. lake expansion, drawdown, drainage) is challenging due to absence of long-term, sustainable monitoring programs in these remote locations. Old Crow Flats (OCF), Yukon, is a Ramsar Wetland of International Importance where concerns about low water levels and their consequences for wildlife habitat and traditional ways of life prompted multidisciplinary studies during the International Polar Year (2007–2008) and led to the establishment of an aquatic ecosystem monitoring program. Here, we report water isotope data from 14 representative thermokarst lakes in OCF, the foundation of the monitoring program, and time-series of derived metrics including the isotope composition of input waters and evaporation-to-inflow ratios for a 13 year period (2007–2019). Although the lakes spanned multiple hydrological categories (i.e. rainfall-, snowmelt- and evaporation-dominated) based on initial surveys, well-defined trends from application of generalized additive models and meteorological records reveal that lakes have become increasingly influenced by rainfall, and potentially waters from thawing permafrost. These sources of input have led to more positive lake water balances. Given the documented role of rainfall in causing thermokarst lake drainage events in OCF and elsewhere, we anticipate increased vulnerability of lateral water export from OCF. This study demonstrates the value of long-term isotope-based monitoring programs for identifying hydrological consequences of climate change in lake-rich permafrost landscapes.

2018 ◽  
Vol 26 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Joshua G. Cronmiller ◽  
Bram F. Noble

Long-term regional environmental monitoring, coupled with shorter-term and more localized monitoring carried out under regulatory permitting processes, is foundational to identifying, understanding, and effectively managing cumulative environmental effects. However, monitoring programs that emerge to support cumulative effects science are often short-lived initiatives or disconnected from land use planning and regulatory decision making. This paper examines the history and evolution of environmental monitoring in the Lower Athabasca region of Alberta, Canada, and the enabling and constraining influences of institutional arrangements. Methods involved a review of regional-scale monitoring programs based on an analysis of monitoring agency mandates, performance reports, and external program reviews, supplemented by discussions with monitoring program or agency key informants to triangulate results. Results show that monitoring to support cumulative effects understanding in the Lower Athabasca has advanced considerably, especially since the mid-1990s, but its relevance to, and impact on, cumulative effects management and decision making has been stifled by institutional arrangements. Monitoring has been episodic, reflecting shifting priorities and competing mandates; criticized by stakeholders based on concerns about transparency, credibility, influence over decision making; and characterized by short-lived commitments by the agencies involved. This has generated significant uncertainty about the stability of institutional arrangements to support long-term environmental monitoring, and tensions between the need for scientific autonomy for credible science whilst ensuring the pursuit of monitoring questions that are relevant to the day-to-day needs of regulatory decision makers. Regional monitoring programs require, at a minimum, clear vision and agreed-upon monitoring questions that are of scientific and management value, meaningful and balanced stakeholder engagement, and a clear governance process to ensure credibility and influence of monitoring results on decision making.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. D. Lowther ◽  
I. Staniland ◽  
C. Lydersen ◽  
K. M. Kovacs

Abstract The fishery for Antarctic krill is currently managed using a precautionary, ecosystem-based approach to limiting catch, with performance indices from a long-term monitoring program focused on several krill-dependent predators that are used to track ecosystem health. Concerns over increased fishing in concentrated areas and ongoing efforts to establish a Marine Protected Area along the Peninsula, a key fishing region, is driving the development of an adaptive management system for the fishery. The cumulative effects of fishing effort and interactions among krill-dependent predators and their performance is at present neglected in the CCAMLR Ecosystem Monitoring Program. However, we show considerable overlap between male Antarctic fur seals and the krill fishery in a complex mosaic, suggesting potential for cumulative impacts on other krill dependent predators. A holistic view is required as part of future efforts to manage the krill fishery that incorporates various sources of potential impacts on the performance of bioindicator species, including the fishery and its interactions with various krill dependent predators.


ARCTIC ◽  
2017 ◽  
Vol 70 (2) ◽  
pp. 177 ◽  
Author(s):  
Trevor C. Lantz

Increases in the frequency and magnitude of disturbances associated with the thawing of ice-rich permafrost highlight the need to understand long-term vegetation succession in permafrost environments. This study uses field sampling and remote sensing to explore vegetation development and soil conditions following catastrophic lake drainage in Old Crow Flats (OCF). The data presented show that vegetation on drained lake basins in OCF is characterized by two distinct assemblages: tall willow stands and sedge swards. Field sampling indicates that these alternative successional trajectories result from variation in soil moisture following drainage. Increased willow mortality on older drained basins suggests that intraspecific competition drives self-thinning in shrub thickets. This finding, combined with data from paleoecological studies and contemporary vegetation in OCF, suggests that willow stands on drained lake basins are seral communities. These results also indicate that the increase in number of catastrophic drainages that occurred between 1972 and 2010 will alter regional vegetation in ways that affect wildlife habitat, permafrost conditions, and local hydrology.


Author(s):  
Dylan Stompe ◽  
Peter Moyle ◽  
Avery Kruger ◽  
John Durand

Many fishes in the San Francisco Estuary have suffered declines in recent decades, as shown by numerous long-term monitoring programs. A long-term monitoring program, such as the Interagency Ecological Program, comprises a suite of surveys, each conducted by a state or federal agency or academic institution. These types of programs have produced rich data sets that are useful for tracking species trends over time. Problems arise from drawing conclusions based on one or few surveys because each survey samples a different subset of species or reflects different spatial or temporal trends in abundance. The challenges in using data sets from these surveys for comparative purposes stem from methodological differences, magnitude of data, incompatible data formats, and end-user preference for familiar surveys. To improve the utility of these data sets and encourage multi-survey analyses, we quantitatively rate these surveys based on their ability to represent species trends, present a methodology for integrating long-term data sets, and provide examples that highlight the importance of expanded analyses. We identify areas and species that are under-sampled, and compare fish salvage data from large water export facilities with survey data. Our analysis indicates that while surveys are redundant for some species, no two surveys are completely duplicative. Differing trends become evident when considering individual and aggregate survey data, because they imply spatial, seasonal, or gear-dependent catch. Our quantitative ratings and integrated data set allow for improved and better-informed comparisons of species trends across surveys, while highlighting the importance of the current array of sampling methodologies.


2016 ◽  
Vol 15 (03) ◽  
pp. A02 ◽  
Author(s):  
Rowan Converse ◽  
Daniel Shaw ◽  
Kim Eichhorst ◽  
May Leinhart

Despite the rapid expansion of citizen-based monitoring, data from these programs remain underutilized by natural resource managers, perhaps due to quality and comparability issues. We present the Bosque Ecosystem Monitoring Program as a case study of an initiative successfully meeting long-term monitoring needs of federal, state, tribal, and local natural resource managers, and informing public policy. To maximize potential for partnerships with managers, we recommend the creation of a five-year plan including scientific goals and financial solvency strategies prior to establishing a citizen science program, and offering multiple platforms for data-sharing and dialogue.


1995 ◽  
Vol 1995 (1) ◽  
pp. 977-978
Author(s):  
Alan J. Mearns

ABSTRACT Halfway through a 10-year monitoring program, NOAA continues to track biological, chemical, and shoreline profile recovery at nearly three dozen sites in Prince William Sound, Alaska. By simple measures (percent visible oil, percent plant cover) all but three or four sites recovered in two to three years. However, by a more integrated biological, chemical, and physical profile, most previously oiled and treated sites are still recovering.


Author(s):  
Ricardo Sánchez-Murillo

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.


2021 ◽  
pp. 193864002199292
Author(s):  
Hope Skibicki ◽  
Sundeep Saini ◽  
Ryan Rogero ◽  
Kristen Nicholson ◽  
Rachel J. Shakked ◽  
...  

Introduction Previous literature has demonstrated an association between acute opioid exposure and the risk of long-term opioid use. Here, the investigators assess immediate postoperative opioid consumption patterns as well as the incidence of prolonged opioid use among opioid-naïve patients following ankle fracture surgery. Methods Included patients underwent outpatient open reduction and internal fixation of an ankle or tibial plafond fracture over a 1-year period. At patients’ first postoperative visit, opioid pills were counted and standardized to the equivalent number of 5-mg oxycodone pills. Prolonged use was defined as filling a prescription for a controlled substance more than 90 days after the index procedure, tracked by the New Jersey Prescription Drug Monitoring Program up to 1 year postoperatively. Results At the first postoperative visit, 173 patients consumed a median of 24 out of 40 pills prescribed. The initial utilization rate was 60%, and 2736 pills were left unused. In all, 32 (18.7%) patients required a narcotic prescription 90 days after the index procedure. Patients with a self-reported history of depression (P = .11) or diabetes (P = .07) demonstrated marginal correlation with prolonged narcotic use. Conclusion Our study demonstrated that, on average, patients utilize significantly fewer opioid pills than prescribed and that many patient demographics are not significant predictors of continued long-term use following outpatient ankle fracture surgery. Large variations in consumption rates make it difficult for physicians to accurately prescribe and predict prolonged narcotic use. Level of Evidence: Level III


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