Experimental management for Snake River spring–summer chinook (Oncorhynchus tshawytscha): trade-offs between conservation and learning for a threatened species

2002 ◽  
Vol 59 (4) ◽  
pp. 717-725 ◽  
Author(s):  
Charles M Paulsen ◽  
Richard A Hinrichsen

Using Snake River spring–summer chinook (Oncorhynchus tshawytscha) as an example, we explore trade-offs between conservation (restoring population abundance to self-sustaining levels) and learning (reliably estimating how management strategies affect productivity). The population has been studied extensively, especially since 1992, when the evolutionarily significant unit (ESU) was listed under the U.S. Endangered Species Act. Understanding both the conservation and learning dimensions is crucial in evaluating management actions. Using a Bayesian simulation model calibrated with 40+ years of spawner–recruit estimates, we performed population viability analyses to examine the biological risks of an array of management strategies. We also performed power analyses to estimate the precision of estimates of the actions' effects. The results suggest that if one can take actions that increase productivity and manage those actions as experiments, one can simultaneously increase fish numbers and reduce the uncertainty about the effects of those actions. However, because more powerful experiments will utilize controls where no action is taken, an experimental approach may increase risks to the ESU when compared to a strategy that tries to maximize productivity as soon as possible.


2018 ◽  
Vol 15 (2) ◽  
pp. 171-217
Author(s):  
Hendrik Schoukens

The concept of adaptive management is generally defined as a flexible decision-making process that can be adjusted in the face of uncertainties as outcomes of management actions and other events become better understood. These experimental management strategies, which may grant permit agencies more discretion to authorise economic developments, have become increasingly popular as tools to overcome deadlock scenarios in the context of the EU Nature Directives. One notable application is the Dutch Programmatic Approach to Nitrogen (Programma Aanpak Stikstof – PAS ), which puts forward a more reconciliatory and integrated approach towards permitting additional nitrogen emissions in the vicinity of Natura 2000 sites. The purpose of this paper is to use the Dutch PAS as a benchmark to explore the margins available within the EU Nature Directives to implement more flexible adaptive management strategies. This paper argues that the Dutch PAS, especially taking into account the immediate trade-off that is provided between future restoration actions and ongoing harmful effects, appears to stand at odds with the substantive underpinning of the EU Nature Directives. As a result, its concrete application might be stalled through legal actions which advocate for a more restrictive approach to the authorization of additional impacts on vulnerable EU protected nature. It therefore remains highly doubtful whether the Dutch PAS is to be presented as a textbook example of a genuine sustainable management strategy within the context of EU environmental law.



2016 ◽  
Vol 8 (2) ◽  
pp. 163-175 ◽  
Author(s):  
Seth P. Tuler ◽  
Thomas Webler ◽  
Jason L. Rhoades

Abstract Numerous decision support tools have been developed to assist stormwater managers to understand future scenarios and devise management strategies. This paper presents one such tool, the Vulnerability, Consequences, and Adaptation Planning Scenarios (VCAPS) process, and reports on experiences from its deployment in 10 coastal communities on the Atlantic and Gulf coasts. VCAPS helps to elucidate local complexities, couplings, and contextual nuance through dialogue among technical experts and those with detailed contextual knowledge of a community. Participants in the process develop qualitative scenarios of climate change impacts and how different management strategies may prevent or mitigate undesirable consequences. The scenarios help stormwater managers diagnose potential problems that may emerge from climate change and variability, which can then be subject to further detailed analysis. The authors describe five challenges faced by stormwater managers and how insights that emerge from scenario-based processes like VCAPS can help address them: characterizing the implications of interacting climate stressors that originate stormwater, bringing all available expertise and local knowledge to bear on the problem of stormwater management, integrating local and scientific information about coupled human–environment systems, identifying management actions and their trade-offs, and facilitating planning for sustained coordination among multiple public and private entities.



2021 ◽  
Vol 288 (1964) ◽  
Author(s):  
Jameal F. Samhouri ◽  
Blake E. Feist ◽  
Mary C. Fisher ◽  
Owen Liu ◽  
Samuel M. Woodman ◽  
...  

Despite the increasing frequency and magnitude of extreme climate events, little is known about how their impacts flow through social and ecological systems or whether management actions can dampen deleterious effects. We examined how the record 2014–2016 Northeast Pacific marine heatwave influenced trade-offs in managing conflict between conservation goals and human activities using a case study on large whale entanglements in the U.S. west coast's most lucrative fishery (the Dungeness crab fishery). We showed that this extreme climate event diminished the power of multiple management strategies to resolve trade-offs between entanglement risk and fishery revenue, transforming near win–win to clear win–lose outcomes (for whales and fishers, respectively). While some actions were more cost-effective than others, there was no silver-bullet strategy to reduce the severity of these trade-offs. Our study highlights how extreme climate events can exacerbate human–wildlife conflict, and emphasizes the need for innovative management and policy interventions that provide ecologically and socially sustainable solutions in an era of rapid environmental change.



1995 ◽  
Vol 52 (7) ◽  
pp. 1442-1448 ◽  
Author(s):  
John M. Emlen

In the presence of historical data, population viability models of intermediate complexity can be parameterized and utilized to project the consequences of various management actions for endangered species. A general stochastic population dynamics model with density feedback, age structure, and autocorrelated environmental fluctuations was constructed and parameterized for best fit over 36 years of spring chinook salmon (Oncorhynchus tshawytscha) redd count data in five Idaho index streams. Simulations indicate that persistence of the Snake River spring chinook salmon population depends primarily on density-independent mortality. Improvement of rearing habitat, predator control, reduced fishing pressure, and improved dam passage all would alleviate density-independent mortality. The current value of the Ricker α should provide for a continuation of the status quo. A recovery of the population to 1957–1961 levels within 100 years would require an approximately 75% increase in survival and (or) fecundity. Manipulations of the Ricker β are likely to have little or no effect on persistence versus extinction, but considerable influence on population size.



2001 ◽  
Vol 58 (6) ◽  
pp. 1196-1207 ◽  
Author(s):  
C E Petrosky ◽  
H A Schaller ◽  
P Budy

Stream-type chinook salmon (Oncorhynchus tshawytscha) populations in the Snake River (northwest United States) have declined dramatically since completion of the federal hydrosystem. Identifying the life stage that is limiting the survival of these stocks is crucial for evaluating the potential of management actions to recover these stocks. We tested the hypothesis that a decrease in productivity and survival rate in the freshwater spawning and rearing (FSR) life stage since completion of the hydropower system could explain the decline observed over the life cycle. The decline of chinook populations following completion of the hydrosystem was not accompanied by major survival changes in the FSR life stage. FSR productivity showed no significant decline, and the FSR survival rate decline was small relative to the overall decline. However, significant survival declines did occur in the smolt-to-adult stage coincident primarily with hydrosystem completion, combined with poorer climate conditions and possibly hatchery effects. Potential improvements in survival that occur only at the FSR life stage are unlikely to offset these impacts and increase survival to a level that ensures the recovery of Snake River stream-type chinook.



2018 ◽  
Author(s):  
Carla Isobel Elliff

Coral reefs provide important ecosystem services to coastal communities. The Archipelago of Tinhar?e andBoipeba, Bahia, Brazil, are mostly surrounded by fringing reefs, which have undergone several chronichuman impacts. The objective of the present study was to apply an ecosystem-based approach byanalyzing the ecosystem services provided by the coral reefs of the Archipelago of Tinhar?e and Boipeba inorder to support management actions and serve as a tool for coastal management. Ecosystem serviceswere assessed through the observation of environmental indicators of their occurrence and by using asuite of models from the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) softwarecombined with data from the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol database. Theservices of greatest occurrence were food provision, habitat maintenance, shoreline protection andrecreation. While the main stressful factors were tourism activities, the absence of a sewage system andfisheries. The coral reefs presented potential for shoreline protection along 50.5% of the islands. Moreover,46.8% of the shoreline would present moderate to high vulnerability in case of coral reef disappearance.The coincidence of areas with high risk of loss in the capacity to provide services and highvulnerability in the scenario of absence of reefs is concerning. Thus, the current model for tourism usedin the area should be altered, as should new management strategies be implemented, which can bringbenefits and avoid reef decline.



2018 ◽  
Vol 54 (3) ◽  
pp. 339-367 ◽  
Author(s):  
Andrew Kwok

This descriptive, mixed methods study of one interim certification program explores first year urban teachers’ classroom management actions. This study investigates what strategies teachers implement to manage the classroom from programmatic surveys of 87 first-year teachers and interviews, field visits, video recordings, and journals of five case participants. Results indicate that teachers used behavioral, academic, and relational strategies to manage the classroom and they tend to refine several of these actions over time. Findings suggest that teacher preparation should promote beginning teachers to implement a range of classroom management strategies and support teachers in how to refine their actions.



2021 ◽  
Vol 49 (1) ◽  
pp. 95-116
Author(s):  
Klaus Keller ◽  
Casey Helgeson ◽  
Vivek Srikrishnan

Accelerating global climate change drives new climate risks. People around the world are researching, designing, and implementing strategies to manage these risks. Identifying and implementing sound climate risk management strategies poses nontrivial challenges including ( a) linking the required disciplines, ( b) identifying relevant values and objectives, ( c) identifying and quantifying important uncertainties, ( d) resolving interactions between decision levers and the system dynamics, ( e) quantifying the trade-offs between diverse values under deep and dynamic uncertainties, ( f) communicating to inform decisions, and ( g) learning from the decision-making needs to inform research design. Here we review these challenges and avenues to overcome them. ▪  People and institutions are confronted with emerging and dynamic climate risks. ▪  Stakeholder values are central to defining the decision problem. ▪  Mission-oriented basic research helps to improve the design of climate risk management strategies.



2021 ◽  
Author(s):  
Charlotte Marcinko ◽  
Robert Nicholls ◽  
Tim Daw ◽  
Sugata Hazra ◽  
Craig Hutton ◽  
...  

<p>The United Nations Sustainable Development Goals (SDGs) and their corresponding targets are significantly interconnected, with many interactions, synergies and trade-offs between individual goals across multiple temporal and spatial scales.  We propose a framework for the Integrated Assessment Modelling (IAM) of a complex deltaic socio-ecological system in order to analyse such SDG interactions. We focus on the Sundarbans Biosphere Reserve (SBR), India within the Ganges-Brahmaputra-Meghna Delta. It is densely populated with 4.4 million people (2011), high levels of poverty and a strong dependence on rural livelihoods. It is only 50 km from the growing megacity of Kolkata (about 15 million people in 2020). The area also includes the Indian portion of the world’s largest mangrove forest – the Sundarbans – hosting the iconic Bengal Tiger. Like all deltaic systems, this area is subject to multiple drivers of environmental change operating across different scales. The IAM framework is designed to investigate current and future trends in socio-environmental change and explore associated policy impacts, considering a broad range of sub-thematic SDG indicators. Integration is achieved through the soft coupling of multiple sub-models, knowledge and data of relevant environmental and socio-economic processes.  The following elements are explicitly considered: (1) agriculture; (2) aquaculture; (3) mangroves; (4) fisheries; and (5) multidimensional poverty. Key questions that can be addressed include the implications of changing monsoon patterns, trade-offs between agriculture and aquaculture, or the future of the Sundarbans mangroves under sea-level rise and different management strategies, including trade-offs with land use to the north.  The novel high-resolution analysis of SDG interactions allowed by the IAM will provide stakeholders and policy makers the opportunity to prioritize and explore the SDG targets that are most relevant to the SBR and provide a foundation for further integrated analysis.</p>



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