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Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales

Includes bibliographical references (leaves 111-148).

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Bibliographic Details
Main Author: Wieters, Evie A
Other Authors: Branch, George M
Format: Thesis
Language:English
Published: Department of Biological Sciences 2014
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access_status_str Open Access
author Wieters, Evie A
author2 Branch, George M
author_browse Branch, George M
Wieters, Evie A
author_facet Branch, George M
Wieters, Evie A
author_sort Wieters, Evie A
collection Thesis
description Includes bibliographical references (leaves 111-148).
format Thesis
id oai:open.uct.ac.za:11427/6115
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:32:21.936Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Department of Biological Sciences
publisherStr Department of Biological Sciences
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/6115 Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales Wieters, Evie A Branch, George M Zoology Includes bibliographical references (leaves 111-148). In Chapter 1, I characterize geographic patterns in rocky intertidal communities across 6° of latitude along the west coast of South Africa and examine the spatial structure of functional group biomass in relation to wave action and upwelling intensity. Despite between-habitat differences in biomass, most functional groups showed similar regional trends in exposed and sheltered habitats, but weaker non-significant between-habitat associations were observed when considering differences due to site. Divese geographic trends were observed, with only specialized kelp-trapping limpets showing a smoothly decreasing trend with latitide. Abrupt changes in the abundance of several species were observed at about 32° or near 34.5° S. Correlations between functional groups were strongest in the low (exposed) and mid (sheltered) shores, and supported the possibility that species interactions, particularly (1) competitive dominance by filter feeders and gardening limpets and (2) habitat facilitation by filter feeders partially account for local differences in functional-group abundances. Nearshore oceanographic conditions were characterized using satellite-measured sea surface temperature (SST), verification by in situ loggers, and analysis of Offshore Ekman Transport (OET) indices. A clear discontinuity at about 32° S partitioned the coast into a northern region characterized by consistenly strong and spatially homogenous upwelling, and a southern region distinguished by significant mesoscale variation in seasonal upwelling intensity among sites, with clear upwelling centers alternating with "downstream" areas only weakly influenced by upwelling. Functional group relationships with SST differed between north and south regions. Local abundances were generally more variable in the south, where greater biomass of ephemeral and corticated macroalgae, as well specialized gardening and kelp-trapping limpets, were associated with upwelling centers. In contrast, high-shore filter-feeder and predator biomasses were significantly greater at downstream sites. These results suggest that oceanographic discontinuities around 32° S may frame community dynamics and that upwelling intensity influences community structure and generates regular spatial differences in interaction webs along the South West Cape. This study represents the critical first step to identifying spatial scales at which processes regulate communities, and provides a series of testable hypotheses that can be evaluated by experimental comparative approaches. 2014-08-13T14:04:32Z 2014-08-13T14:04:32Z 2006 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/6115 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town
spellingShingle Zoology
Wieters, Evie A
Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales
thesis_degree_str Doctoral
title Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales
title_full Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales
title_fullStr Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales
title_full_unstemmed Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales
title_short Benthic-pelagic coupling : rocky intertidal communities and nearshore oceanographic conditions across multiple scales
title_sort benthic pelagic coupling rocky intertidal communities and nearshore oceanographic conditions across multiple scales
topic Zoology
url http://hdl.handle.net/11427/6115
work_keys_str_mv AT wieterseviea benthicpelagiccouplingrockyintertidalcommunitiesandnearshoreoceanographicconditionsacrossmultiplescales