Animal sediment interactions : macrofauna community structure and sediments of an intertidal mudflat, Southampton Water, UK
Animal sediment interactions : macrofauna community structure and sediments of an intertidal mudflat, Southampton Water, UK
Interdisciplinary research, incorporating macrobenthic ecology and sediment dynamics, was undertaken in order to investigate the effects of recharge on the lower shore of an intertidal mudflat at Hythe, Hampshire, UK. A field programme was carried out to examine the impact of a trial recharge experiment (planned and carried out by ABP) on the macrofauna community and associated sediments, and to collect baseline information on the site. The fieldwork included biological sampling, in situ physico-chemical measurements of key environmental parameters, measurements to identify changes in bed elevation indicative of accretion or erosion at the site, and the collection of sediment cores for analysis of sediment properties and structure.
Both the field (and the CT) studies indicated that no significant deposition of material occurred at the site as a result of recharge and the benthic community was unaffected. This is in agreement with the results of surveys carried out by ABP which concluded that the deposited material was transported away from the site by the tidal currents (ABP, 2001). Results obtained from the smothering experiments indicated that effects were species specific, and were dependent upon animal functional morphology. Tolerance thresholds for species ranged from less than 2 cm of burial (e.g. H. ulvae) to >50 cm (N. diversicolor). No clear relationship was identified between τc and macrofauna density from the erosion experiments. Results suggest that erosion rate and gradient as a relative measure of internal friction coefficient («problem!») may be better parameters for future investigation, as causative relationships were implied. Experimental effects arising from instrument differences, laboratory effects and treatment effects were identified and are addressed. CT proved to be a highly suitable technique for the investigation of sediment structure and fine-scale bulk density distribution. Several distinct layers of sediment including a collapse zone (sensu Droppo and Amos, 2001) and self-weight consolidation were identified from the bulk density data. Faunal modification of sediment structure by bioturbation, and individual burrows were also identified. No long-term, or seasonal trends of erosion or deposition were revealed by the CT images and data, and earlier observations were supported in that no clear signs of recharge were evident.
University of Southampton
Lindsay, Michelle Dawn
9920f526-f7e6-455d-9a47-2c1dd46e42a5
2003
Lindsay, Michelle Dawn
9920f526-f7e6-455d-9a47-2c1dd46e42a5
Lindsay, Michelle Dawn
(2003)
Animal sediment interactions : macrofauna community structure and sediments of an intertidal mudflat, Southampton Water, UK.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Interdisciplinary research, incorporating macrobenthic ecology and sediment dynamics, was undertaken in order to investigate the effects of recharge on the lower shore of an intertidal mudflat at Hythe, Hampshire, UK. A field programme was carried out to examine the impact of a trial recharge experiment (planned and carried out by ABP) on the macrofauna community and associated sediments, and to collect baseline information on the site. The fieldwork included biological sampling, in situ physico-chemical measurements of key environmental parameters, measurements to identify changes in bed elevation indicative of accretion or erosion at the site, and the collection of sediment cores for analysis of sediment properties and structure.
Both the field (and the CT) studies indicated that no significant deposition of material occurred at the site as a result of recharge and the benthic community was unaffected. This is in agreement with the results of surveys carried out by ABP which concluded that the deposited material was transported away from the site by the tidal currents (ABP, 2001). Results obtained from the smothering experiments indicated that effects were species specific, and were dependent upon animal functional morphology. Tolerance thresholds for species ranged from less than 2 cm of burial (e.g. H. ulvae) to >50 cm (N. diversicolor). No clear relationship was identified between τc and macrofauna density from the erosion experiments. Results suggest that erosion rate and gradient as a relative measure of internal friction coefficient («problem!») may be better parameters for future investigation, as causative relationships were implied. Experimental effects arising from instrument differences, laboratory effects and treatment effects were identified and are addressed. CT proved to be a highly suitable technique for the investigation of sediment structure and fine-scale bulk density distribution. Several distinct layers of sediment including a collapse zone (sensu Droppo and Amos, 2001) and self-weight consolidation were identified from the bulk density data. Faunal modification of sediment structure by bioturbation, and individual burrows were also identified. No long-term, or seasonal trends of erosion or deposition were revealed by the CT images and data, and earlier observations were supported in that no clear signs of recharge were evident.
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Published date: 2003
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Local EPrints ID: 465268
URI: http://eprints.soton.ac.uk/id/eprint/465268
PURE UUID: 23b10cfa-e2ac-427a-80ab-d090f3cc7bbd
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Date deposited: 05 Jul 2022 00:34
Last modified: 16 Mar 2024 20:04
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Author:
Michelle Dawn Lindsay
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