Analysis of Per Capita Contributions from a Spatial Model Provides Strategies for Controlling Spread of Invasive Carp

Metapopulation models may be applied to inform natural resource management to guide actions targeted at location-specific subpopulations. Model insights frequently help to understand which subpopulations to target and highlight the importance of connections among subpopulations. For example, managers often treat aquatic invasive species populations as discrete populations due to hydrological (e.g., lakes, pools formed by dams) or jurisdictional boundaries (e.g., river segments by country or jurisdictional units such as states or provinces). However, aquatic invasive species often have high rates of dispersion and migration among heterogenous locations, which complicates traditional metapopulation models and may not conform to management boundaries. Controlling invasive species requires consideration of spatial dynamics because local management activities (e.g., harvest, movement deterrents) may have important impacts on connected subpopulations. We expand upon previous work to create a spatial linear matrix model for an aquatic invasive species, Bighead Carp, in the Illinois River, USA, to examine the per capita contributions of specific subpopulations and impacts of different management scenarios on these subpopulations. Managers currently seek to prevent Bighead Carp from invading the Great Lakes via a connection between the Illinois Waterway and Lake Michigan by allocating management actions across a series of river pools. We applied the model to highlight how spatial variation in movement rates and recruitment can affect decisions about where management activities might occur. We found that where the model suggested management actions should occur depend crucially on the specific management goal (i.e., limiting the growth rate of the metapopulation vs. limiting the growth rate of the invasion front) and the per capita recruitment rate in downstream pools. Our findings illustrate the importance of linking metapopulation dynamics to management goals for invasive species control

Incorporating metapopulation Dynamics to Inform Invasive Species Management: Evaluating Bighead and Silver Carp Control Strategies in the Illinois River

1. Invasive species management can benefit from predictive models that incorporate spatially explicit demographics and dispersal to guide resource allocation decisions. 2. We used invasive bigheaded carps (Hypophthalmichthys spp.) in the Illinois River, USA as a case study to create a spatially explicit model to evaluate the allocation of future management efforts. Specifically, we compared additional harvest (e.g. near the invasion front vs. source populations) and enhanced movement deterrents to meet the management goal of reducing abundance at the invasion front. 3. We found additional harvest in lower river pools (i.e. targeting source populations) more effectively limited population sizes upriver at the invasion front compared to allocating the same harvest levels near the invasion front. Likewise, decreasing passage (i.e. lock and dam structures) at the farthest, feasible downriver location limited invasion front population size more than placing movement deterrents farther upriver. 4. Synthesis and applications. Our work highlights the benefits of adopting a multipronged approach for invasive species management, combining suppression of source populations with disrupting movement between source and sink populations thereby producing compounding benefits for control. Our results also demonstrate the importance of considering metapopulation dynamics for invasive species control programs when achieving long-term management goals

Hydrological Controls and Freshening in Meromictic Soap Lake, Washington, 1939‐2002

The chemically stratified layer of naturally formed meromictic lakes exhibits unusual and often extreme physical and chemical conditions that have resulted in the evolution of uniquely adapted species. The Columbia Basin Irrigation Project appears to have had a marked effect on the hydrology of Soap Lake, a meromictic lake in the Grand Coulee of central Washington. The relation of hydrology to salinity was assessed by analyzing water budgets before and after the introduction of the irrigation project. Before irrigation, water gains were balanced by losses; after irrigation began groundwater gains approximately doubled. To manage lake levels and reduce groundwater influx, wells were installed to intercept groundwater. Although the hydrological cycle has been restored to pre‐irrigation conditions, the meromictic character of the lake continues to change. Interception wells remove 10 to 16 Mm3 of groundwater annually, but influx continues based on change in the monimolimnion. From 1958 to 2003 the chemocline descended 1.1m and the volume of the monimolimnion from 698,000m3 to 114,000m3. Annual loss of volume is occurring at a rate of 1.9% since 1958. Although groundwater interception wells are maintaining the volume of the entire lake, the recession of the chemocline indicates that conditions that have maintained meromixis at Soap Lake are currently not in equilibrium

Analysis of per capita contributions from a spatial model provides strategies for controlling spread of invasive carp

Abstract Metapopulation models may be applied to inform natural resource management to guide actions targeted at location‐specific subpopulations. Model insights frequently help to understand which subpopulations to target and highlight the importance of connections among subpopulations. For example, managers often treat aquatic invasive species populations as discrete populations due to hydrological (e.g., lakes, pools formed by dams) or jurisdictional boundaries (e.g., river segments by country or jurisdictional units such as states or provinces). However, aquatic invasive species often have high rates of dispersion and migration among heterogenous locations, which complicates traditional metapopulation models and may not conform to management boundaries. Controlling invasive species requires consideration of spatial dynamics because local management activities (e.g., harvest, movement deterrents) may have important impacts on connected subpopulations. We expand upon previous work to create a spatial linear matrix model for an aquatic invasive species, Bighead Carp, in the Illinois River, USA, to examine the per capita contributions of specific subpopulations and impacts of different management scenarios on these subpopulations. Managers currently seek to prevent Bighead Carp from invading the Great Lakes via a connection between the Illinois Waterway and Lake Michigan by allocating management actions across a series of river pools. We applied the model to highlight how spatial variation in movement rates and recruitment can affect decisions about where management activities might occur. We found that where the model suggested management actions should occur depend crucially on the specific management goal (i.e., limiting the growth rate of the metapopulation vs. limiting the growth rate of the invasion front) and the per capita recruitment rate in downstream pools. Our findings illustrate the importance of linking metapopulation dynamics to management goals for invasive species control

Rain Gauges to Range Conditions: Collaborative Development of a Drought Information System to Support Local Decision-Making

Drought monitoring and drought planning are complex endeavors. Measures of precipitation or streamflow provide little context for understanding how social and environmental systems impacted by drought are responding. Here the authors report on collaborative work with the Hopi Tribe-a Native American community in the U.S. Southwest-to develop a drought information system that is responsive to local needs. A strategy is presented for developing a system that is based on an assessment of how drought is experienced by Hopi citizens and resource managers, that can incorporate local observations of drought impacts as well as conventional indicators, and that brings together local expertise with conventional science-based observations. The system described here is meant to harness as much available information as possible to inform tribal resource managers, political leaders, and citizens about drought conditions and to also engage these local drought stakeholders in observing, thinking about, and helping to guide planning for drought.National Oceanic and Atmospheric Administration's Climate Program Office from the Regional Integrated Science and Assessment program [NA13OAR4310166]; Sectoral Applications Research Program [NA10OAR4310183]Published Online: 18 August 2016; 6 month embargoThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

From planetary to societal boundaries: an argument for collectively defined self-limitation

The planetary boundaries concept has profoundly changed the vocabulary and representation of global environmental issues. We bring a critical social science perspective to this framework through the notion of societal boundaries and aim to provide a more nuanced understanding of the social nature of thresholds. We start by highlighting the strengths and weaknesses of planetary boundaries from a social science perspective. We then focus on capitalist societies as a heuristic for discussing the expansionary dynamics, power relations, and lock-ins of modern societies that impel highly unsustainable societal relations with nature. While formulating societal boundaries implies a controversial process ‒ based on normative judgments, ethical concerns, and socio-political struggles ‒ it has the potential to offer guidelines for a just, social-ecological transformation. Collective autonomy and the politics of self-limitation are key elements of societal boundaries and are linked to important proposals and pluriverse experiences to integrate well-being and boundaries. The role of the state and propositions for radical alternative approaches to well-being have particular importance. We conclude with reflections on social freedom, defined as the right not to live at others’ expense. Toward the aim of defining boundaries through transdisciplinary and democratic processes, we seek to open a dialogue on these issues

From planetary to societal boundaries: an argument for collectively defined self-limitation

The planetary boundaries concept has profoundly changed the vocabulary and representation of global environmental issues. We bring a critical social science perspective to this framework through the notion of societal boundaries and aim to provide a more nuanced understanding of the social nature of thresholds. We start by highlighting the strengths and weaknesses of planetary boundaries from a social science perspective. We then focus on capitalist societies as a heuristic for discussing the expansionary dynamics, power relations, and lock-ins of modern societies that impel highly unsustainable societal relations with nature. While formulating societal boundaries implies a controversial process ‒ based on normative judgments, ethical concerns, and socio-political struggles ‒ it has the potential to offer guidelines for a just, social-ecological transformation. Collective autonomy and the politics of self-limitation are key elements of societal boundaries and are linked to important proposals and pluriverse experiences to integrate well-being and boundaries. The role of the state and propositions for radical alternative approaches to well-being have particular importance. We conclude with reflections on social freedom, defined as the right not to live at others’ expense. Toward the aim of defining boundaries through transdisciplinary and democratic processes, we seek to open a dialogue on these issues. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group