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A brief introduction to some approaches to multispecies/ecosystem modelling in the context of their possible application in the management of South African fisheries
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: D. S. Butterworth É. E. PlagányiAspects of the potential application of multispecies/ecosystem modelling to advise the management of South African fisheries are discussed. In general, reliable predictive ability from such models is likely to be achieved sooner for top predators, because relatively fewer links need... -
Simulations of fishing effects on the southern Benguela fish community using an individual-based model: learning from a comparison with ECOSIM
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: Y-J. Shin L. J. Shannon P. M. CuryBy applying an individual-based model (OSMOSE) to the southern Benguela ecosystem, a multispecies analysis is proposed, complementary to that provided by the application of ECOPATH/ECOSIM models. To reconstruct marine foodwebs, OSMOSE is based on the hypothesis that predation is a... -
Consideration of multispecies interactions in the Antarctic: a preliminary model of the minke whale – blue whale – krill interaction
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M. Mori D. S. ButterworthAs a first step in investigating the major predator–prey interactions in the Antarctic, a model describing blue whales Balaenoptera musculus, minke whales Balaenoptera acutorostrata and krill Euphausia superba is developed. Blue and minke whales feed mainly on krill, and they... -
A critical look at the potential of Ecopath with ecosim to assist in practical fisheries management
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: É. E. Plagányi D. S. ButterworthEcosystem-orientated thinking is increasingly incorporated into fishery management. Given the complexity of ecosystem processes, there is a need to evaluate the tools used to steer this thinking critically. ECOPATH with ECOSIM (EwE), an aggregate system-modelling package, is currently the most... -
Age structure or functional response? Reconciling the energetics of surplus production between single-species models and ECOSIM
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K. Y. AydinWhole-ecosystem foodweb models, specifically the dynamic model ECOSIM, contain specific hypotheses for surplus production that differ from traditional single-species management models. Specifically, ECOSIM begins with an assumption that all species are tightly connected and energetic surplus does not arise through... -
Characteristics and value of the Thukela Banks crustacean and linefish fisheries, and the potential impacts of changes in river flow
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JK Turpie --- Anchor Environmental Consultants, South Africa SJ Lamberth --- Branch Fisheries, Department of Agriculture, Forestry and Fisheries, South AfricaThis study describes the Thukela Banks crustacean and linefish fisheries and investigates the potential impacts of reduced flow from the Thukela River on the value of these fisheries. Data were obtained from published and unpublished material, key informants and government... -
Seasonal fluctuations in occurrence of inshore Bryde's whales in Plettenberg Bay, South Africa, with notes on feeding and multispecies associations
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: GS Penry --- , UK VG Cockcroft --- Department of Zoology, Nelson Mandela Metropolitan University, South Africa PS Hammond --- , UKSeasonal fluctuations in the occurrence of inshore South African Bryde's whales Balaenoptera edeni were investigated between November 2005 and June 2008. Sighting data were collected in Plettenberg Bay on the south-east coast of South Africa. Bryde's whale occurrence was modelled... -
A simple implementation of the statistical modelling framework Gadget for cod in Icelandic waters
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L Taylor J Begley V Kupca G StefanssonGadget is a statistical modelling framework that can be used to assess individual fish stocks and to create multispecies, multi-fleet and multi-area models. The development of a complex multispecies model requires understanding of the modelled single-species population. Simple single-species models... -
Prioritising species for research, conservation and management: a case study of exploited fish species
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SJ Lamberth --- Branch: Fisheries Management, Department of Agriculture, South Africa AR Joubert --- Southern Waters Ecological Research and Consulting, South AfricaStudies that categorise species according to their conservation status often fall short in their implementation by not having taken into account the impacts on, or the response from, those that either benefit from, or exploit, the resource under consideration. This... -
Evaluating Kenya’s coastal gillnet fishery: trade-offs in recommended mesh-size regulations
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K Osuka --- , Kenya JA Kawaka --- , Kenya MA Samoilys --- , KenyaGillnets are a widely used fishing gear in Kenya’s artisanal fisheries, yet their mesh sizes are inadequately monitored or regulated. This study evaluated the impacts of gillnets of seven stretched-mesh sizes, through comparative analysis of species-related metrics and catch per... -
Walking with herders: following into the multispecies classroom
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: William Ellis --- , South Africa Clement Cupido --- , South Africa Mogamat Igshaan Samuels --- , South AfricaThe recently developed walking ethnography, or go-along method, to study pastoralists in a participatory manner provides data that the usual sit-down interview is unable to realise, not least because it shifts the power dynamic between researcher and researched. The herder’s... -
A meeting with gardenia: an ethnographic exploration of multispecies relationships and space construction in Kirstenbosch National Botanical Garden
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: James Granelli --- University of Cape Town, South AfricaIn an age of climate and ecological breakdown, questions of how we relate to the natural world and the more-than-human beings around us are more important than ever. This ethnography seeks to bring these questions to the Kirstenbosch National Botanical... -
Crossing Etosha: a history of donkeys in Namibia’s central north
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Luregn Lenggenhager --- University of Cologne, Germany Giorgio Miescher --- University of Basel, Switzerland Romie Nghitevelekwa --- University of Namibia, Namibia Martha Akawa --- University of Namibia, NamibiaDonkeys are a common sight in Namibia’s central north and play an important albeit contested role in rural society and economy. Historically, they were one of the few domesticated animals that were allowed to enter today’s Etosha National Park and... -
Performing multispecies studies in Southern Africa: historical legacies, marginalised subjects, reflexive positionalities
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Paula Alexiou --- University of Cologne, Germany Julia Brekl --- University of Cologne, Germany Emilie Köhler --- University of Cologne, Germany Wisse van Engelen --- University of Cologne, GermanyMultispecies studies are known for tackling human exceptionalism. Whilst the field has seen a remarkable increase in popularity amongst scholars in the humanities and social sciences, critiques argue that it neglects inequalities and consequential differences amongst humans and between humans... -
The beast that never forgot? Baboon conservation and the role of multispecies history
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Sandra Swart --- Stellenbosch University, South AfricaHistory and culture were long seen as definitionally human. As other distinctive traits that once defined our species as unique disappeared, at least we still had those two. But are we really the only species shaped by our pasts and... -
Killing tsetse and/or saving wildlife? A multispecies assemblage in colonial Zambia (1895–1959)
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Léa Lacan --- University of Cologne, GermanyThis article investigates the problem of the tsetse fly and the trypanosomiasis disease it conveys as a transforming multispecies assemblage in colonial Zambia from the late nineteenth century until 1959. Based on archival research, it analyses the tsetse fly (Glossina...