Managing for RADical ecosystem change Lynch, Abigail J; Thompson, Laura M; Beever, Erik A ...
Frontiers in ecology and the environment,
10/2021, Letnik:
19, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Ecosystem transformation involves the emergence of persistent ecological or social–ecological systems that diverge, dramatically and irreversibly, from prior ecosystem structure and function. Such ...transformations are occurring at increasing rates across the planet in response to changes in climate, land use, and other factors. Consequently, a dynamic view of ecosystem processes that accommodates rapid, irreversible change will be critical for effectively conserving fish, wildlife, and other natural resources, and maintaining ecosystem services. However, managing ecosystems toward states with novel structure and function is an inherently unpredictable and difficult task. Managers navigating ecosystem transformation can benefit from considering broader objectives, beyond a traditional focus on resisting ecosystem change, by also considering whether accepting inevitable change or directing it along some desirable pathway is more feasible (that is, practical and appropriate) under some circumstances (the RAD framework). By explicitly acknowledging transformation and implementing an iterative RAD approach, natural resource managers can be deliberate and strategic in addressing profound ecosystem change.
Abstract
Intensifying global change is propelling many ecosystems toward irreversible transformations. Natural resource managers face the complex task of conserving these important resources under ...unprecedented conditions and expanding uncertainty. As once familiar ecological conditions disappear, traditional management approaches that assume the future will reflect the past are becoming increasingly untenable. In the present article, we place adaptive management within the resist–accept–direct (RAD) framework to assist informed risk taking for transforming ecosystems. This approach empowers managers to use familiar techniques associated with adaptive management in the unfamiliar territory of ecosystem transformation. By providing a common lexicon, it gives decision makers agency to revisit objectives, consider new system trajectories, and discuss RAD strategies in relation to current system state and direction of change. Operationalizing RAD adaptive management requires periodic review and update of management actions and objectives; monitoring, experimentation, and pilot studies; and bet hedging to better identify and tolerate associated risks.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ecosystem transformation can be defined as the emergence of a self‐organizing, self‐sustaining, ecological or social–ecological system that deviates from prior ecosystem structure and function. These ...transformations are occurring across the globe; consequently, a static view of ecosystem processes is likely no longer sufficient for managing fish, wildlife, and other species. We present a framework that encompasses three strategies for fish and wildlife managers dealing with ecosystems vulnerable to transformation. Specifically, managers can resist change and strive to maintain existing ecosystem composition, structure, and function; accept transformation when it is not feasible to resist change or when changes are deemed socially acceptable; or direct change to a future ecosystem configuration that would yield desirable outcomes. Choice of a particular option likely hinges on anticipating future change, while also acknowledging that temporal and spatial scales, recent history and current state of the system, and magnitude of change can factor into the decision. This suite of management strategies can be implemented using a structured approach of learning and adapting as ecosystems change.
Fisheries management is a complex task made even more challenging by rapid and unprecedented socioecological transformations associated with climate change. The Resist‐Accept‐Direct (RAD) framework ...can be a useful tool to support fisheries management in facing the high uncertainty and variability associated with aquatic ecosystem transformations. Here, RAD strategies are presented to address ecological goals for aquatic ecosystems and social goals for fisheries. These strategies are mapped on a controllability matrix which explores the ability to guide a system's behaviour towards a desired state based on ecological responsiveness and societal receptivity to change. Understanding and improving the controllability of aquatic systems and fisheries can help managers to maintain the broadest suite of available RAD management strategies.
Resumen
El manejo de recursos pesqueros es una tarea compleja que se complica aun más con las transformaciones socioecológicas asociadas al cambio climático. El marco de Resistir‐Aceptar‐Dirigir (RAD) puede ser una herramienta útil para la toma de decisiones en el manejo pesquero en cara a la alta incertidumbre y variabilidad asociada a las transformaciones de los ecosistemas acuáticos. Aquí se presentan las estrategias de RAD en cuanto a los objetivos ecológicos para los sistemas acuáticos y objetivos sociológicos para las pesquerías. Dichas estrategias están presentadas en una matriz de control, la cual explora la habilidad de guiar el comportamiento de un sistema hacia el estado deseado basado en la capacidad ecológica a responder al manejo y la receptividad social a cambios. Entender y mejorar el nivel de control de sistemas acuáticos y pesquerías puede ayudar a los manejadores a mantener una amplia selección de estrategias de manejo RAD.
Aging of reservoirs alters the functions, and associated services, of these systems through time. The goal of habitat rehabilitation is often to alter the trajectory of the aging process such that ...the duration of the desired state is prolonged. There are two important characteristics in alteration of the trajectory—the amplitude relative to current state and the subsequent rate of change, or aging—that ultimately determine the duration of extension for the desired state. Rehabilitation processes largely fall into three main categories: fish community manipulation, water quality manipulation, and physical habitat manipulation. We can slow aging of reservoirs through carefully implemented management actions, perhaps even turning back the hands of time, but we cannot stop aging. We call for new, innovative perspectives that incorporate an understanding of aging processes in all steps of rehabilitation of reservoirs, especially in planning and assessing.
Catfish 2020, A Clear Vision of the Future Porath, Mark T.; Kwak, Thomas J.; Neely, Ben C. ...
North American journal of fisheries management,
October 2021, 2021-10-00, Letnik:
41, Številka:
S1
Journal Article
Recenzirano
The Third International Catfish Symposium was held in Little Rock, Arkansas, in 2020 and provided another milestone to gauge advances in knowledge related to conservation and management of these ...valuable fishes. Attendees from 29 states and 4 countries gathered to communicate research and information on the conservation, ecology, and management of the world’s catfishes. During 3 d of technical sessions and workshops, 74 oral presentations and 17 posters were shared with 198 attending fisheries professionals. Plenary and oral presentations were recorded and are available online (https://www.youtube.com/channel/UCHNt7ZV05DLWoe4qJO798Pw/videos), aligning with the symposium theme of “Communicating Catfish Science.” Technical sessions explored current research and management issues that included population demographics, introduced catfish populations, sampling methods, harvest management, human dimensions, conservation, habitat use and movement, biology, and aging methods. Ultimately, 38 manuscripts were peer reviewed and published as this special issue of the North American Journal of Fisheries Management. Interest in catfish science, as gauged by publications in six peer‐reviewed fisheries journals, has grown steadily since a 1910 catfish aquaculture article appeared in the Transactions of the American Fisheries Society. Biology and ecology topics became prominent in the 1970s and 1980s, while articles on techniques and fisheries management have grown steadily through 2020. Ecology, fisheries management, and techniques were the most published topics in the three international catfish symposia. Future research and management efforts will continue similar work but also seek to address the expanding role of catfish as invasive species and a better understanding of the ecology and conservation of small‐bodied native catfish. Among the greatest challenges will be adapting current tools and identifying future knowledge gaps as we experience a changing climate. This will require an enhanced understanding of transforming ecosystems and advanced adaptive management applications. The decadal occurrence of a dedicated symposium has served to summarize progress and focus future efforts to advance catfish science.
Lakes and reservoirs progress through an aging process often accelerated by human activities, resulting in degradation or loss of ecosystem services. Resource managers thus attempt to slow or reverse ...the negative effects of aging using a myriad of rehabilitation strategies. Sustained monitoring programs to assess the efficacy of rehabilitation strategies are often limited; however, long-term standardized fishery surveys may be a valuable data source from which to begin evaluation. We present 3 case studies using standardized fishery survey data to assess rehabilitation efforts stemming from the Nebraska Aquatic Habitat Plan, a large-scale program with the mission to rehabilitate waterbodies within the state. The case studies highlight that biotic responses to rehabilitation efforts can be assessed, to an extent, using standardized fishery data; however, there were specific areas where minor increases in effort would clarify the effectiveness of rehabilitation techniques. Management of lakes and reservoirs can be streamlined by maximizing the utility of such datasets to work smarter, not harder. To facilitate such efforts, we stress collecting both biotic (e.g., fish lengths and weight) and abiotic (e.g., dissolved oxygen, pH, and turbidity) data during standardized fishery surveys and designing rehabilitation actions with an appropriate experimental design.
We used quantile regression to compare the body condition of walleye Sander vitreus and white bass Morone chrysops before (1980–1988) and after (1989–2004) the establishment of alewives Alosa ...pseudoharengus in Lake McConaughy, Nebraska. Higher quantiles (percentiles = 100% × quantiles (0, 1)) of weight (W) at the same total length (TL) were indicative of better body condition in an allometric growth model that included separate slopes and intercepts for the before and after groups. All quantiles of walleye weights by TL increased in the years after alewife introduction, ranging from 1.01 to 1.12 times weights in the years before alewife introduction, with greatest increases for the lower (<0.50) quantiles and greater TLs. Quantiles up to 0.25 (the lowest 25th percentiles) of white bass weights were reduced in years after alewife introduction for TLs less than 300 mm, ranging from 0.78 to 0.98 times weights in the years before alewife introduction. However, quantiles greater than or equal to 0.50 (the upper 50th percentiles) of white bass weights increased for all TLs, ranging from 1.01 to 1.06 times the pre‐1988 weights. A three‐group analysis, which improved the model fit for longer white bass, indicated a reduction (0.80–1.0) in white bass body condition across all TLs in the first 2 years (1989–1990) after alewife introduction, whereas body condition actually improved (1.02–1.12) across all TLs in later years (1991–2004). Thus, after the establishment of alewives in 1988, walleye body condition improved for all fish at all lengths (the greatest improvement occurring among fish in poorer condition), whereas white bass body condition was initially reduced for all fish at all lengths for 2 years and improved in subsequent years. The approach that we developed for comparing fish body condition before and after a management action in Lake McConaughy could be applied to other weight–length data sets typically evaluated with relative weight indices.
PDF
