{"id":{"repo_id":"soton","oai_identifier":"oai:eprints.soton.ac.uk:63289"},"canonical_url":"https://search.dev.ndltd.org/etd/soton/oai:eprints.soton.ac.uk:63289","repository":{"repo_id":"soton","name":"University of Southampton","base_url":"https://eprints.soton.ac.uk/cgi/oai2"},"display":{"title":"The role of coastal defence structures in channeling production in coastal ecosystems","abstract":"This study assessed the interaction of coastal defence structures (CDSs), namely shore-parallel<br/>‘low crested breakwater structures’ (LCSs), design features and hydrodynamic regime on the<br/>quantity and timings of macroalgae deposition. The employed sampling strategy comprised a<br/>spatially and temporally stratitified approach of time-lapse photography of macroalgae<br/>deposition, verified with field observations. Field surveys determined the associated ecological<br/>assemblages of the sediment infauna and rocky shore epifauna associated with the breakwater<br/>scheme, as well as for two nearby beaches with groynes. Further analysis determined decay<br/>rates, decay processes, changes in C and N stable isotope values of dominant macroalgal species<br/>and the dependence of the faunal assemblages on the decaying macroalgae deposits. Temporal<br/>analysis highlights the main factors driving macroalgal deposition were differences in spring<br/>and neap tidal range, wave height and sea temperature. Greatest deposition occurred during<br/>months of lower wave height and fewer storms, when filamentous red algae and ephemeral<br/>green algal species dominated. Results indicated to greater amounts of macroalgae deposits<br/>around LCSs than around wooden or granite groynes. Beach elevation best explained the spatial<br/>variation, both vertically and horizontally, in the benthic assemblages within the breakwater<br/>scheme, with the abundance of detritivorous deposit feeders being significantly correlated with<br/>abundance of macroalgae deposits. Orientation of LCSs, relative to wave action, was an<br/>important driver of epifaunal assemblages on the CDSs, with the eastward ends of the<br/>breakwaters providing the optimum intermediate environment with regards to wave action,<br/>exhibiting the greatest abundances of epifauna. Stable isotope analysis showed that the carbon<br/>and nitrogen isotopic values of macroalgae changed during the decomposition and were both<br/>species and time dependent. Isotope analysis illustrated that decaying macroalgae deposits were<br/>of greater trophic importance to species within the LCS ecosystem where there was large<br/>macroalgal deposition, than to species within the groyne ecosystem where macroalgal<br/>deposition was lower. Key findings of the study illustrate the importance of decaying<br/>macroalgae deposits for the local ecosystem via modification of food chain energy flows.<br/>Though the ecosystem benefits from this allochthonous resource, deposits may be a nuisance<br/>requiring controlled human intervention.","abstract_html":"This study assessed the interaction of coastal defence structures (CDSs), namely shore-parallel&lt;br/&gt;‘low crested breakwater structures’ (LCSs), design features and hydrodynamic regime on the&lt;br/&gt;quantity and timings of macroalgae deposition. The employed sampling strategy comprised a&lt;br/&gt;spatially and temporally stratitified approach of time-lapse photography of macroalgae&lt;br/&gt;deposition, verified with field observations. Field surveys determined the associated ecological&lt;br/&gt;assemblages of the sediment infauna and rocky shore epifauna associated with the breakwater&lt;br/&gt;scheme, as well as for two nearby beaches with groynes. Further analysis determined decay&lt;br/&gt;rates, decay processes, changes in C and N stable isotope values of dominant macroalgal species&lt;br/&gt;and the dependence of the faunal assemblages on the decaying macroalgae deposits. Temporal&lt;br/&gt;analysis highlights the main factors driving macroalgal deposition were differences in spring&lt;br/&gt;and neap tidal range, wave height and sea temperature. Greatest deposition occurred during&lt;br/&gt;months of lower wave height and fewer storms, when filamentous red algae and ephemeral&lt;br/&gt;green algal species dominated. Results indicated to greater amounts of macroalgae deposits&lt;br/&gt;around LCSs than around wooden or granite groynes. Beach elevation best explained the spatial&lt;br/&gt;variation, both vertically and horizontally, in the benthic assemblages within the breakwater&lt;br/&gt;scheme, with the abundance of detritivorous deposit feeders being significantly correlated with&lt;br/&gt;abundance of macroalgae deposits. Orientation of LCSs, relative to wave action, was an&lt;br/&gt;important driver of epifaunal assemblages on the CDSs, with the eastward ends of the&lt;br/&gt;breakwaters providing the optimum intermediate environment with regards to wave action,&lt;br/&gt;exhibiting the greatest abundances of epifauna. Stable isotope analysis showed that the carbon&lt;br/&gt;and nitrogen isotopic values of macroalgae changed during the decomposition and were both&lt;br/&gt;species and time dependent. Isotope analysis illustrated that decaying macroalgae deposits were&lt;br/&gt;of greater trophic importance to species within the LCS ecosystem where there was large&lt;br/&gt;macroalgal deposition, than to species within the groyne ecosystem where macroalgal&lt;br/&gt;deposition was lower. Key findings of the study illustrate the importance of decaying&lt;br/&gt;macroalgae deposits for the local ecosystem via modification of food chain energy flows.&lt;br/&gt;Though the ecosystem benefits from this allochthonous resource, deposits may be a nuisance&lt;br/&gt;requiring controlled human intervention.","abstract_has_math":false,"creators":["Jolley, Elizabeth Charlotte"],"institution":"University of Southampton","degree_name":"Ph.D.","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008-06","date_published":"2008-06","updated_at":"2026-07-24T04:35:54Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Jolley, Elizabeth Charlotte"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2008-06"]},{"key":"dc:date.issued","label":"Date","values":["2008-06"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["National Oceanography Centre,Southampton (pre 2011 reorg)","Ocean and Earth Science (pre 2011 reorg)","School of Ocean and Earth Science"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Southampton"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://eprints.soton.ac.uk/63289/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Ph.D."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://eprints.soton.ac.uk/63289/1/Jolley_2008_PhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study assessed the interaction of coastal defence structures (CDSs), namely shore-parallel<br/>‘low crested breakwater structures’ (LCSs), design features and hydrodynamic regime on the<br/>quantity and timings of macroalgae deposition. The employed sampling strategy comprised a<br/>spatially and temporally stratitified approach of time-lapse photography of macroalgae<br/>deposition, verified with field observations. Field surveys determined the associated ecological<br/>assemblages of the sediment infauna and rocky shore epifauna associated with the breakwater<br/>scheme, as well as for two nearby beaches with groynes. Further analysis determined decay<br/>rates, decay processes, changes in C and N stable isotope values of dominant macroalgal species<br/>and the dependence of the faunal assemblages on the decaying macroalgae deposits. Temporal<br/>analysis highlights the main factors driving macroalgal deposition were differences in spring<br/>and neap tidal range, wave height and sea temperature. Greatest deposition occurred during<br/>months of lower wave height and fewer storms, when filamentous red algae and ephemeral<br/>green algal species dominated. Results indicated to greater amounts of macroalgae deposits<br/>around LCSs than around wooden or granite groynes. Beach elevation best explained the spatial<br/>variation, both vertically and horizontally, in the benthic assemblages within the breakwater<br/>scheme, with the abundance of detritivorous deposit feeders being significantly correlated with<br/>abundance of macroalgae deposits. Orientation of LCSs, relative to wave action, was an<br/>important driver of epifaunal assemblages on the CDSs, with the eastward ends of the<br/>breakwaters providing the optimum intermediate environment with regards to wave action,<br/>exhibiting the greatest abundances of epifauna. Stable isotope analysis showed that the carbon<br/>and nitrogen isotopic values of macroalgae changed during the decomposition and were both<br/>species and time dependent. Isotope analysis illustrated that decaying macroalgae deposits were<br/>of greater trophic importance to species within the LCS ecosystem where there was large<br/>macroalgal deposition, than to species within the groyne ecosystem where macroalgal<br/>deposition was lower. Key findings of the study illustrate the importance of decaying<br/>macroalgae deposits for the local ecosystem via modification of food chain energy flows.<br/>Though the ecosystem benefits from this allochthonous resource, deposits may be a nuisance<br/>requiring controlled human intervention."]},{"key":"dc:format","label":"Dc Format","values":["text"]},{"key":"dc:title","label":"Title","values":["The role of coastal defence structures in channeling production in coastal ecosystems"]}]}],"canonical_facts":{"dc:creator":["Jolley, Elizabeth Charlotte"],"dc:date":["2008-06"],"dc:date.issued":["2008-06"],"dc:description.abstract":["This study assessed the interaction of coastal defence structures (CDSs), namely shore-parallel<br/>‘low crested breakwater structures’ (LCSs), design features and hydrodynamic regime on the<br/>quantity and timings of macroalgae deposition. The employed sampling strategy comprised a<br/>spatially and temporally stratitified approach of time-lapse photography of macroalgae<br/>deposition, verified with field observations. Field surveys determined the associated ecological<br/>assemblages of the sediment infauna and rocky shore epifauna associated with the breakwater<br/>scheme, as well as for two nearby beaches with groynes. Further analysis determined decay<br/>rates, decay processes, changes in C and N stable isotope values of dominant macroalgal species<br/>and the dependence of the faunal assemblages on the decaying macroalgae deposits. Temporal<br/>analysis highlights the main factors driving macroalgal deposition were differences in spring<br/>and neap tidal range, wave height and sea temperature. Greatest deposition occurred during<br/>months of lower wave height and fewer storms, when filamentous red algae and ephemeral<br/>green algal species dominated. Results indicated to greater amounts of macroalgae deposits<br/>around LCSs than around wooden or granite groynes. Beach elevation best explained the spatial<br/>variation, both vertically and horizontally, in the benthic assemblages within the breakwater<br/>scheme, with the abundance of detritivorous deposit feeders being significantly correlated with<br/>abundance of macroalgae deposits. Orientation of LCSs, relative to wave action, was an<br/>important driver of epifaunal assemblages on the CDSs, with the eastward ends of the<br/>breakwaters providing the optimum intermediate environment with regards to wave action,<br/>exhibiting the greatest abundances of epifauna. Stable isotope analysis showed that the carbon<br/>and nitrogen isotopic values of macroalgae changed during the decomposition and were both<br/>species and time dependent. Isotope analysis illustrated that decaying macroalgae deposits were<br/>of greater trophic importance to species within the LCS ecosystem where there was large<br/>macroalgal deposition, than to species within the groyne ecosystem where macroalgal<br/>deposition was lower. Key findings of the study illustrate the importance of decaying<br/>macroalgae deposits for the local ecosystem via modification of food chain energy flows.<br/>Though the ecosystem benefits from this allochthonous resource, deposits may be a nuisance<br/>requiring controlled human intervention."],"dc:format":["text"],"dc:identifier.uri":["https://eprints.soton.ac.uk/63289/1/Jolley_2008_PhD.pdf"],"dc:publisher.department":["National Oceanography Centre,Southampton (pre 2011 reorg)","Ocean and Earth Science (pre 2011 reorg)","School of Ocean and Earth Science"],"dc:publisher.institution":["University of Southampton"],"dc:relation.isreferencedby":["https://eprints.soton.ac.uk/63289/"],"dc:title":["The role of coastal defence structures in channeling production in coastal ecosystems"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["Ph.D."]},"updated_at":"2026-07-24T04:35:54Z"}