Simmons Samantha E.

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Samantha E.

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Now showing 1 - 4 of 4
  • Article
    Understanding the combined effects of multiple stressors: a new perspective on a longstanding challenge
    (Elsevier, 2022-01-29) Pirotta, Enrico ; Thomas, Len ; Costa, Daniel P. ; Hall, Ailsa J. ; Harris, Catriona M. ; Harwood, John ; Kraus, Scott D. ; Miller, Patrick J. O. ; Moore, Michael J. ; Photopoulou, Theoni ; Rolland, Rosalind M. ; Schwacke, Lori ; Simmons, Samantha E. ; Southall, Brandon L. ; Tyack, Peter L.
    Wildlife populations and their habitats are exposed to an expanding diversity and intensity of stressors caused by human activities, within the broader context of natural processes and increasing pressure from climate change. Estimating how these multiple stressors affect individuals, populations, and ecosystems is thus of growing importance. However, their combined effects often cannot be predicted reliably from the individual effects of each stressor, and we lack the mechanistic understanding and analytical tools to predict their joint outcomes. We review the science of multiple stressors and present a conceptual framework that captures and reconciles the variety of existing approaches for assessing combined effects. Specifically, we show that all approaches lie along a spectrum, reflecting increasing assumptions about the mechanisms that regulate the action of single stressors and their combined effects. An emphasis on mechanisms improves analytical precision and predictive power but could introduce bias if the underlying assumptions are incorrect. A purely empirical approach has less risk of bias but requires adequate data on the effects of the full range of anticipated combinations of stressor types and magnitudes. We illustrate how this spectrum can be formalised into specific analytical methods, using an example of North Atlantic right whales feeding on limited prey resources while simultaneously being affected by entanglement in fishing gear. In practice, case-specific management needs and data availability will guide the exploration of the stressor combinations of interest and the selection of a suitable trade-off between precision and bias. We argue that the primary goal for adaptive management should be to identify the most practical and effective ways to remove or reduce specific combinations of stressors, bringing the risk of adverse impacts on populations and ecosystems below acceptable thresholds.
  • Article
    A standardisation framework for bio-logging data to advance ecological research and conservation
    (Wiley, 2021-03-15) Sequeira, Ana M. M. ; O'Toole, Malcolm ; Keates, Theresa R. ; McDonnell, Laura H. ; Braun, Camrin D. ; Hoenner, Xavier ; Jaine, Fabrice R. A. ; Jonsen, Ian ; Newman, Peggy ; Pye, Jonathan ; Bograd, Steven ; Hays, Graeme ; Hazen, Elliott L. ; Holland, Melinda ; Tsontos, Vardis ; Blight, Clint ; Cagnacci, Francesca ; Davidson, Sarah C. ; Dettki, Holger ; Duarte, Carlos M. ; Dunn, Daniel C. ; Eguíluz, Víctor M. ; Fedak, Michael ; Gleiss, Adrian C. ; Hammerschlag, Neil ; Hindell, Mark ; Holland, Kim ; Janekovic, Ivica ; McKinzie, Megan K. ; Muelbert, Monica M. C. ; Pattiaratchi, Charitha ; Rutz, Christian ; Sims, David W. ; Simmons, Samantha E. ; Townsend, Brendal ; Whoriskey, Frederick G. ; Woodward, Bill ; Costa, Daniel P. ; Heupel, Michelle R. ; McMahon, Clive R. ; Harcourt, Robert ; Weise, Michael
    1. Bio-logging data obtained by tagging animals are key to addressing global conservation challenges. However, the many thousands of existing bio-logging datasets are not easily discoverable, universally comparable, nor readily accessible through existing repositories and across platforms, slowing down ecological research and effective management. A set of universal standards is needed to ensure discoverability, interoperability and effective translation of bio-logging data into research and management recommendations. 2. We propose a standardisation framework adhering to existing data principles (FAIR: Findable, Accessible, Interoperable and Reusable; and TRUST: Transparency, Responsibility, User focus, Sustainability and Technology) and involving the use of simple templates to create a data flow from manufacturers and researchers to compliant repositories, where automated procedures should be in place to prepare data availability into four standardised levels: (a) decoded raw data, (b) curated data, (c) interpolated data and (d) gridded data. Our framework allows for integration of simple tabular arrays (e.g. csv files) and creation of sharable and interoperable network Common Data Form (netCDF) files containing all the needed information for accuracy-of-use, rightful attribution (ensuring data providers keep ownership through the entire process) and data preservation security. 3. We show the standardisation benefits for all stakeholders involved, and illustrate the application of our framework by focusing on marine animals and by providing examples of the workflow across all data levels, including filled templates and code to process data between levels, as well as templates to prepare netCDF files ready for sharing. 4. Adoption of our framework will facilitate collection of Essential Ocean Variables (EOVs) in support of the Global Ocean Observing System (GOOS) and inter-governmental assessments (e.g. the World Ocean Assessment), and will provide a starting point for broader efforts to establish interoperable bio-logging data formats across all fields in animal ecology.
  • Article
    Deadly diving? Physiological and behavioural management of decompression stress in diving mammals
    (Royal Society, 2011-12-21) Hooker, Sascha K. ; Fahlman, Andreas ; Moore, Michael J. ; Aguilar De Soto, Natacha ; Bernaldo de Quiros, Yara ; Brubakk, A. O. ; Costa, Daniel P. ; Costidis, Alexander M. ; Dennison, Sophie ; Falke, K. J. ; Fernandez, Antonio ; Ferrigno, Massimo ; Fitz-Clarke, J. R. ; Garner, Michael M. ; Houser, Dorian S. ; Jepson, Paul D. ; Ketten, Darlene R. ; Kvadsheim, P. H. ; Madsen, Peter T. ; Pollock, N. W. ; Rotstein, David S. ; Rowles, Teresa K. ; Simmons, S. E. ; Van Bonn, William ; Weathersby, P. K. ; Weise, Michael ; Williams, Terrie M. ; Tyack, Peter L.
    Decompression sickness (DCS; ‘the bends’) is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N2) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N2 loading to management of the N2 load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.
  • Article
    Managing the effects of multiple stressors on wildlife populations in their ecosystems: developing a cumulative risk approach
    (The Royal Society, 2022-11-30) Tyack, Peter L. ; Thomas, Len ; Costa, Daniel P. ; Hall, Ailsa J. ; Harris, Catriona M. ; Harwood, John ; Kraus, Scott D. ; Miller, Patrick J. O. ; Moore, Michael ; Photopoulou, Theoni ; Pirotta, Enrico ; Rolland, Rosalind M. ; Schwacke, Lori H. ; Simmons, Samantha E. ; Southall, Brandon L.
    Assessing cumulative effects of human activities on ecosystems is required by many jurisdictions, but current science cannot meet regulatory demands. Regulations define them as effect(s) of one human action combined with other actions. Here we argue for an approach that evaluates the cumulative risk of multiple stressors for protected wildlife populations within their ecosystems. Monitoring effects of each stressor is necessary but not sufficient to estimate how multiple stressors interact to affect wildlife populations. Examining the mechanistic pathways, from cellular to ecological, by which stressors affect individuals can help prioritize stressors and interpret how they interact. Our approach uses health indicators to accumulate the effects of stressors on individuals and to estimate changes in vital rates, driving population status. We advocate using methods well-established in human health and integrating them into ecosystem-based management to protect the health of commercially and culturally important wildlife populations and to protect against risk of extinction for threatened species. Our approach will improve abilities to conserve and manage ecosystems but will also demand significant increases in research and monitoring effort. We advocate for increased investment proportional to the economic scale of human activities in the Anthropocene and their pervasive effects on ecology and biodiversity.