Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela

Simple item page
dc.contributor.authorWatermeyer, Katherine Een_ZA
dc.contributor.authorHutchings, Laurenceen_ZA
dc.contributor.authorJarre, Astriden_ZA
dc.contributor.authorShannon, Lynne Jen_ZA
dc.date.accessioned2016-10-31T07:39:42Z
dc.date.available2016-10-31T07:39:42Z
dc.date.issued2016en_ZA
dc.description.abstractSeveral commercially and ecologically important species in the southern Benguela have undergone southward and eastward shifts in their distributions over previous decades, most notably the small pelagic fish sardine Sardinops sagax and anchovy Engraulis encrasicolus . Understanding these changes and their implications is essential in implementing an ecosystem approach to fisheries in the southern Benguela and attempting to appreciate the potential impacts of future environmental change. To investigate possible impacts of these shifts at an ecosystem level, distribution maps for before (1985-1991), during (1997-2000) and after (2003-2008) the shift in small pelagic fish were constructed for 14 key species from catch and survey data, and used to calculate spatial indicators including proportion east and west of Cape Agulhas, relative overlap in biomass and area, index of diversity, connectivity. Potential interactions on the south and west coasts were also compared. For several species (redeye; chub mackerel; kingklip; chokka squid; yellowtail), previously unidentified increases in the proportion of biomass east of Cape Agulhas were shown to have occurred over the same period as that of small pelagic fish, although none to the same degree. On average, overlap with small pelagic fish increased over time and overall system connectivity was lowest in the intermediate period, possibly indicating a system under transition. Connectivity declined over time on the west coast while increasing on the east coast. Distributions of other species have changed over time, with the region east of Cape Agulhas becoming increasingly important in terms of potential trophic interaction. Variations in distribution of biomass and structural complexity affect the trophic structure and hence functioning of the system, and implications should be considered when attempting to identify the possible ecosystem impacts of current and future system-level change.en_ZA
dc.identifier.apacitationWatermeyer, K. E., Hutchings, L., Jarre, A., & Shannon, L. J. (2016). Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela. <i>PLoS One</i>, http://hdl.handle.net/11427/22367en_ZA
dc.identifier.chicagocitationWatermeyer, Katherine E, Laurence Hutchings, Astrid Jarre, and Lynne J Shannon "Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela." <i>PLoS One</i> (2016) http://hdl.handle.net/11427/22367en_ZA
dc.identifier.citationWatermeyer, K. E., Hutchings, L., Jarre, A., & Shannon, L. J. (2016). Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela. PloS one, 11(7), e0158734. doi:10.1371/journal.pone.0158734en_ZA
dc.identifier.ris TY - Journal Article AU - Watermeyer, Katherine E AU - Hutchings, Laurence AU - Jarre, Astrid AU - Shannon, Lynne J AB - Several commercially and ecologically important species in the southern Benguela have undergone southward and eastward shifts in their distributions over previous decades, most notably the small pelagic fish sardine Sardinops sagax and anchovy Engraulis encrasicolus . Understanding these changes and their implications is essential in implementing an ecosystem approach to fisheries in the southern Benguela and attempting to appreciate the potential impacts of future environmental change. To investigate possible impacts of these shifts at an ecosystem level, distribution maps for before (1985-1991), during (1997-2000) and after (2003-2008) the shift in small pelagic fish were constructed for 14 key species from catch and survey data, and used to calculate spatial indicators including proportion east and west of Cape Agulhas, relative overlap in biomass and area, index of diversity, connectivity. Potential interactions on the south and west coasts were also compared. For several species (redeye; chub mackerel; kingklip; chokka squid; yellowtail), previously unidentified increases in the proportion of biomass east of Cape Agulhas were shown to have occurred over the same period as that of small pelagic fish, although none to the same degree. On average, overlap with small pelagic fish increased over time and overall system connectivity was lowest in the intermediate period, possibly indicating a system under transition. Connectivity declined over time on the west coast while increasing on the east coast. Distributions of other species have changed over time, with the region east of Cape Agulhas becoming increasingly important in terms of potential trophic interaction. Variations in distribution of biomass and structural complexity affect the trophic structure and hence functioning of the system, and implications should be considered when attempting to identify the possible ecosystem impacts of current and future system-level change. DA - 2016 DB - OpenUCT DO - 10.1371/journal.pone.0158734 DP - University of Cape Town J1 - PLoS One LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela TI - Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela UR - http://hdl.handle.net/11427/22367 ER - en_ZA
dc.identifier.urihttp://dx.doi.org/10.1371/journal.pone.0158734en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22367
dc.identifier.vancouvercitationWatermeyer KE, Hutchings L, Jarre A, Shannon LJ. Patterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguela. PLoS One. 2016; http://hdl.handle.net/11427/22367.en_ZA
dc.language.isoengen_ZA
dc.publisherPublic Library of Scienceen_ZA
dc.publisher.departmentMarine Research (MA-RE) Instituteen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.rightsThis is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en_ZA
dc.rights.holder© 2016 Watermeyer et alen_ZA
dc.rights.urihttp://creativecommons.org/licenses/by/4.0en_ZA
dc.sourcePLoS Oneen_ZA
dc.source.urihttp://journals.plos.org/plosoneen_ZA
dc.subject.otherBiomass (ecology)en_ZA
dc.subject.otherFisheriesen_ZA
dc.subject.otherSpecies interactionsen_ZA
dc.subject.otherEcosystemsen_ZA
dc.subject.otherTunaen_ZA
dc.subject.otherTrophic interactionsen_ZA
dc.subject.otherHorsesen_ZA
dc.subject.otherPredationen_ZA
dc.titlePatterns of distribution and spatial indicators of ecosystem change based on key species in the Southern Benguelaen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Watermeyer_Patterns_of_Distribution_2016.pdf
Size:
4.51 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Journal Articles