Department of Biology, Dalhousie University, Halifax
Empirical Links Between Demography, Life History, and Recovery in Fishes
November 2, 2017 at 12:00pm
Studies on small and declining populations dominate research in conservation biology. This emphasis reflects two overarching frameworks: the small-population paradigm focuses on correlates of increased extinction probability; the declining-population paradigm directs attention to the causes and consequences of depletion. Neither, however, particularly informs research on the determinants, rate, or uncertainty of population increase. Compounding this deficiency is the problem that most meta-analyses used to detect Allee effects (declining per capita productivity with declining population size) have been fraught with theoretical and methodological limitations.
I adopt an alternative approach, examining the correlates of observed, rather than predicted, abundance trajectories for populations that have and have not recovered from depletion, despite threat mitigation. Based on these empirically based analyses, two key conclusions emerge for fishes that are inconsistent with prevailing scientific beliefs and perceptions.
Firstly, the greater the reduction in population size, the greater the likelihood that Allee effects impair recovery. Secondly, in contrast to multiple studies, life-history traits appear to be poor predictors of recovery when considered singly. In combination, however, a subset of traits provides compelling evidence for the hypothesis that rate of natural mortality (M), or a metric thereof, provides an empirically tractable and theoretically defensible predictor of recovery potential.
Bio: After obtaining a PhD at Memorial University of Newfoundland, Jeffrey Hutchings worked at Edinburgh University (Scotland) and Fisheries & Oceans Canada (St. John’s) before accepting a position at Dalhousie University, where he was recently (2016) appointed Dalhousie’s Killam Chair in Fish, Fisheries and Oceans. Since 2010, he has also held three academic positions in Norway. His work on fish ecology, evolution, and population dynamics has been published in more than 210 peer-reviewed scientific articles. He has chaired four national committees, including Canada’s science advisory body on species at risk (COSEWIC; 2006-2010). Since 1997, Hutchings has been invited to appear before 11 parliamentary Standing Committees. Co-founder and Past-President of the Canadian Society for Ecology and Evolution, he chaired the Royal Society of Canada Expert Panel (2012) on the effects of climate change, fisheries, and aquaculture on Canadian marine biodiversity. He was elected Fellow of the Royal Society of Canada (Academy of Science) in 2015.
Jo (Jayeeta) Sharma
Department of Historical and Cultural Studies, University of Toronto Scarborough, Toronto
Collectors, Coolies, and Climbers in the Himalayas: Picturing Indigenous Histories
November 30, 2017 at 12:30pm
This talk focuses on a paper of the same title that examines three key occupations that indigenous people undertook in mountain spaces ruled by the British Empire: plant collectors, coolie labourers, and climbers, and explores their histories of work and life from those. To do so, it interrogates visual and textual materials and discusses how sources as varied as botanical drawings and tourist postcards allow us to write ‘histories from below’ of local and indigenous people, far from the original intent of Euro-American producers. Finally, the paper discusses the Sherpa oral history archive produced in collaboration between UTSC and the Himalayan Club and the exciting possibilities that such digital media offers.
Bio: Jo (Jayeeta) Sharma is an Associate Professor in the Historical and Cultural Studies Department and the Graduate Department of History at the University of Toronto. She studied in Assam and Delhi before she travelled to the University of Cambridge as a Commonwealth Scholar for her PhD in History. She is the author of Empire’s Garden: Assam and the Making of India (Duke 2011), which examines tea plantations and labour migration in the British Empire. She is on the Editorial Board of Global Food History and the Editorial Collective for Radical History Review, and is editor of the Empires in Perspective book series at Routledge. Her research and teaching focus on food, family, global commodities, and diasporic cities. Her current book project explores the making of the Himalayas as a local and global space for cultural encounters and mobile people.