The Influence Of Water Velocity And Depth On Prey Detection And Capture By Juvenile Coho Salmon And Steelhead: Implications For Habitat Selection And Segregation

Thesis (Ph.D.) University of Alaska Fairbanks, 2005I studied the effects of water velocity and depth on drift-foraging by juvenile coho salmon and steelhead to assess how these influence their reported habitat segregation into pools and riffles, respectively. I used three-dimensional video analysis of stream-tank foraging experiments to test how velocity and depth influence prey capture probabilities, and the geometry and dynamics of prey detection and capture. I used the experimental results to develop net energy intake models to predict optimal foraging velocities for coho and steelhead. Prey capture probabilities for both coho and steelhead declined from $65% to 10% with an increase in velocity from 0.29 to 0.61 m · sec -1, with little difference between the species. Capture maneuver characteristics were similar for both species, including reduced prey detection distance and capture probabilities within the capture area, constant prey interception speed, and increasing return speed. I conclude that faster velocity reduces prey capture success by coho and steelhead, but that differences in capture abilities are not responsible for habitat segregation. Prey capture probabilities for both species were constant at ~40% at depths from 0.15 to 0.60 m, with little difference between the species. Capture maneuver characteristics were similar for both species, including increased prey detection distance and interception speed, and constant return speed. I predict that prey capture rate increases proportionally to water depth for coho and steelhead, but that differences in capture probabilities are not responsible for habitat segregation. I used the experimental results to develop net energy intake models that predicted optimum foraging velocities of 0.29 m · s-1 for coho and 0.30 m · s-1 steelhead. Modeled 10% and 25% increases in swimming costs for coho reduced optimum velocity by 0 and 0.01 m · s-1, respectively. These results, coupled with those from the depth experiments, suggest that habitat segregation may be due to factors other than short-term foraging considerations. I propose that these are largely selective mechanisms such as size-based habitat selection, differences in growth trajectories, or prey specialization. I do not discount the possibility that interactive mechanisms are also important, especially at periods of high fish density or limited prey availability

"Nature's contributions to people" and peoples' moral obligations to nature

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has become influential in biodiversity conservation. Its research is published widely and has been adopted by the United Nations and the Convention for Biological Diversity. This platform includes discussion about how values relate to biodiversity conservation. The IPBES emphasizes "relational values", connecting these with living a "good life," and "nature's contributions to people" (NCP); building upon ecosystem services (ES), which have dominated nature valuation for 15+ years. Although the IPBES acknowledges instrumental and intrinsic natural values, they purport that by adopting relational values, conservation will become more socially- and culturally-inclusive, moving beyond the "unhelpful dichotomy" between instrumental and intrinsic values. We wholeheartedly agree that conservation should become more inclusive - it should, in fact, morally include nonhuman nature. We argue that far from being half of an unhelpful dichotomy, intrinsic natural values are incontrovertible elements of any honest effort to sustain Earth's biodiversity. We find NCP to be mainly anthropocentric, and relational values to be largely instrumental. The "good life" they support is a good life for humans, and not for nonhuman beings or collectives. While passingly acknowledging intrinsic natural values, the current IPBES platform gives little attention to these, and to corresponding ecocentric worldviews. In this paper we demonstrate the important practical implications of operationalizing intrinsic values for conservation, such as ecological justice, i.e., "peoples' obligations to nature". We urge the IPBES platform, in their future values work, to become much more inclusive of intrinsic values and ecocentrism

Harmony in Conservation

Many authors have noted the role that anthropocentrism has played in creating humanity’s dysfunctional relationship with the natural world. As human hubris (excessive pride or self-confidence) is an ailment that contributes to the anthropogenic sixth mass extinction of Earth’s biodiversity, we argue instead for ‘harmony with nature’. In recent decades, even the conservation discourse has become increasingly anthropocentric. Indeed, justification for nature conservation has in part shifted from nature’s intrinsic value to ‘ecosystem services’ for the benefit of people. Here we call for a transformation to a more harmonious human-nature relationship that is grounded in mutual respect and principled responsibility, instead of utilitarianism and enlightened self-interest. Far from what Tennyson called ‘red in tooth and claw’, we argue nature is a mixture of cooperation as well as competition. We argue that the UN’s ‘Harmony with Nature’ program is an innovative and refreshing path for change. If we are to achieve harmony with nature, modern industrial society will need to abandon its anthropocentric ‘human supremacy’ mindset and adopt an ecocentric worldview and ecological ethics. We conclude it is thus both appropriate (and essential) for conservationists to champion harmony with nature

Categorical Models for a Semantically Linear Lambda-calculus

This paper is about a categorical approach to model a very simple Semantically Linear lambda calculus, named Sll-calculus. This is a core calculus underlying the programming language SlPCF. In particular, in this work, we introduce the notion of Sll-Category, which is able to describe a very large class of sound models of Sll-calculus. Sll-Category extends in the natural way Benton, Bierman, Hyland and de Paiva's Linear Category, in order to soundly interpret all the constructs of Sll-calculus. This category is general enough to catch interesting models in Scott Domains and Coherence Spaces

Foregrounding ecojustice in conservation

Justice for nature remains a confused term. In recent decades justice has predominantly been limited to humanity, with a strong focus on social justice, and its spin-off – environmental justice for people. We first examine the formal rationale for ecocentrism and ecological ethics, as this underpins attitudes towards justice for nature, and show how justice for nature has been affected by concerns about dualisms and by strong anthropocentric bias. We next consider the traditional meaning of social justice, alongside the recent move by some scholars to push justice for nature into social justice, effectively weakening any move to place ecojustice centre-stage. This, we argue, is both unethical and doomed to failure as a strategy to protect life on Earth. The dominant meaning of ‘environmental justice’ – in essence, justice for humans in regard to environmental issues – is also explored. We next discuss what ecological justice (ecojustice) is, and how academia has ignored it for many decades. The charge of ecojustice being ‘antihuman’ is refuted. We argue that distributive justice can also apply to nature, including an ethic of bio-proportionality, and also consider how to reconcile social justice and ecojustice, arguing that ecojustice must now be foregrounded to ensure effective conservation. After suggesting a ‘Framework for implementing ecojustice’ for conservation practitioners, we conclude by urging academia to foreground ecojustice

Atlantic salmon in regulated rivers: Understanding river management through the ecosystem services lens

Known as the "king of fishes," the Atlantic salmon (Salmo salar, Salmonidae) is an iconic freshwater species whose contribution to human well-being has long been recognized, as have widespread declines in its abundance, partly due to river regulation. To understand how salmon conservation has been addressed within the ecosystem services (ES) framework, we synthesized the peer-reviewed literature on ES provided by salmon in regulated rivers. We developed a search string to capture allusions to provisioning, regulating, supporting and cultural ES and assessed the results to identify knowledge gaps. The effects of hydropower on fisheries catches and on modelled populations were shown in several publications. Overall, few studies focused explicitly on ES from salmon and hydropower; this is surprising given the considerable body of literature on salmon in regulated rivers. Wild salmon as a food source and other provisioning services are less important today than historically. Because predators such as salmon are important for facilitating biodiversity by cycling nutrients and controlling food webs, there is a scope of work for future assessments of these regulating and supporting services. Few papers explicitly addressed cultural ES, despite the salmon's longstanding iconic status; this is a knowledge gap for future ES assessments in relation to hydropower. The influence of ES assessments for policy makers is growing through the Intergovernmental Panel for Biodiversity and Ecosystem Services (IPBES) and the post-2020 biodiversity strategy. Explicitly addressing ES poses an opportunity for river managers to raise awareness of aquatic conservation efforts and well-informed decision-making for sustaining ES

Protecting Half the Planet and Transforming Human Systems Are Complementary Goals

The unfolding crises of mass extinction and climate change call for urgent action in response. To limit biodiversity losses and avert the worst effects of climate disruption, we must greatly expand nature protection while simultaneously downsizing and transforming human systems. The conservation initiative Nature Needs Half (or Half Earth), calling for the conservation of half the Earth's land and seas, is commensurate with the enormous challenges we face. Critics have objected to this initiative as harboring hardship for people near protected areas and for failing to confront the growth economy as the main engine of global ecological destruction. In response to the first criticism, we affirm that conservation policies must be designed and implemented in collaboration with Indigenous and local communities. In response to the second criticism, we argue that protecting half the Earth needs to be complemented by downscaling and reforming economic life, humanely and gradually reducing the global population, and changing food production and consumption. By protecting nature generously, and simultaneously contracting and transforming the human enterprise, we can create the conditions for achieving justice and well-being for both people and other species. If we fail to do so, we instead accept a chaotic and impoverished world that will be dangerous for us all

“Nature's contributions to people” and peoples' moral obligations to nature

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has become influential in biodiversity conservation. Its research is published widely and has been adopted by the United Nations and the Convention for Biological Diversity. This platform includes discussion about how values relate to biodiversity conservation. The IPBES emphasizes “relational values”, connecting these with living a “good life,” and “nature's contributions to people” (NCP); building upon ecosystem services (ES), which have dominated nature valuation for 15+ years. Although the IPBES acknowledges instrumental and intrinsic natural values, they purport that by adopting relational values, conservation will become more socially- and culturally- inclusive, moving beyond the “unhelpful dichotomy” between instrumental and intrinsic values. We wholeheartedly agree that conservation should become more inclusive – it should, in fact, morally include nonhuman nature. We argue that far from being half of an unhelpful dichotomy, intrinsic natural values are incontrovertible elements of any honest effort to sustain Earth's biodiversity. We find NCP to be mainly anthropocentric, and relational values to be largely instrumental. The “good life” they support is a good life for humans, and not for nonhuman beings or collectives. While passingly acknowledging intrinsic natural values, the current IPBES platform gives little attention to these, and to corresponding ecocentric worldviews. In this paper we demonstrate the important practical implications of operationalizing intrinsic values for conservation, such as ecological justice, i.e., “peoples' obligations to nature”. We urge the IPBES platform, in their future values work, to become much more inclusive of intrinsic values and ecocentrism

Three major steps toward the conservation of freshwater and riparian biodiversity

J.M. and J.H. thank Stiftelsen Längmanska kulturfonden for funding travel to the conference. As.L. and K.R. thank the Estonian Research Council (grant 1121) for financial support, and A.M. acknowledges the Leverhulme Trust (RPG-2019-402). H.H. was supported by the European Union Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Actions (grant agreement 860800): RIBES (river flow regulation, fish behaviour, and status), and V.A. acknowledges the support from the Leibniz Competition project Freshwater Megafauna Futures. E.J. received support through the National Laboratory for Health Security (RRF-2.3.1-21-2022-00006), Centre for Ecological Research, Budapest, Hungary, and thanks Z. Molnár for support.Freshwater ecosystems and their bordering wetlands and riparian zones are vital for human society and biological diversity. Yet, they are among the most degraded ecosystems, where sharp declines in biodiversity are driven by human activities, such as hydropower development, agriculture, forestry, and fisheries. Because freshwater ecosystems are characterized by strongly reciprocal linkages with surrounding landscapes, human activities that encroach on or degrade riparian zones ultimately lead to declines in freshwater–riparian ecosystem functioning. We synthesized results of a symposium on freshwater, riparian, and wetland processes and interactions and analyzed some of the major problems associated with improving freshwater and riparian research and management. Three distinct barriers are the lack of involvement of local people in conservation research and management, absence of adequate measurement of biodiversity in freshwater and riparian ecosystems, and separate legislation and policy on riparian and freshwater management. Based on our findings, we argue that freshwater and riparian research and conservation efforts should be integrated more explicitly. Best practices for overcoming the 3 major barriers to improved conservation include more and sustainable use of traditional and other forms of local ecological knowledge, choosing appropriate metrics for ecological research and monitoring of restoration efforts, and mirroring the close links between riparian and freshwater ecosystems in legislation and policy. Integrating these 3 angles in conservation science and practice will provide substantial benefits in addressing the freshwater biodiversity crisis.Peer reviewe

Perceptions of a curriculum vitae clinic for conservation science students

We led a curriculum vitae (CV) clinic aimed at student participants attending the 28th International Congress for Conservation Biology (ICCB 2017) in Cartagena, Colombia. The CV Clinic was a pilot program consisting of resources to assist with developing an effective CV and involving preconference and at-conference reviews of student attendees' CVs. Here, we explore our experiences in organizing the CV Clinic as well as nonparticipant and participant perceptions of the clinic. We used an online standardized interview form to gather qualitative data on nonparticipant and participant perceptions of the CV Clinic, and to explore how such a CV Clinic program could best align with student needs. Most respondents who submitted their CV for review ahead of ICCB 2017 (n = 9) found the template and guidance useful. Half of the respondents who did not participate in the CV Clinic perceived the clinic as duplicating services provided by their academic institutions. Both participant and nonparticipant respondents perceived value in such a CV Clinic, but also believed that adjustments could be made to make the CV review part of a broader professional development program lead by Society for Conservation Biology (SCB). Key lessons learned from the CV Clinic include the need to: (a) document and evaluate professional development initiatives within SCB; (b) better understand and account for the diversity of student needs before program creation; and (c) pilot and evaluate appropriateness of different locations, frequency, and duration of professional development programs