The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent
Includes bibliographical references (leaves 234-254). Significant effort has been put into the development of cost-effective abalone cultivation systems in South Africa, but the limited availability of suitable seaweed for abalone food is an obstacle to future development. The aim of this study was...
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2003
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Online Access: | http://hdl.handle.net/11427/6175 https://open.uct.ac.za/bitstream/11427/6175/1/thesis_sci_2003_robertson_andersson_d%20%281%29.pdf |
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ftunivcapetownir:oai:localhost:11427/6175 2023-05-15T18:41:08+02:00 The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent Robertson-Andersson, Deborah Bolton, J Anderson, R J Probyn, T 2003 application/pdf http://hdl.handle.net/11427/6175 https://open.uct.ac.za/bitstream/11427/6175/1/thesis_sci_2003_robertson_andersson_d%20%281%29.pdf eng eng University of Cape Town Faculty of Science Department of Biological Sciences http://hdl.handle.net/11427/6175 https://open.uct.ac.za/bitstream/11427/6175/1/thesis_sci_2003_robertson_andersson_d%20%281%29.pdf Botany Master Thesis Masters MSc 2003 ftunivcapetownir 2022-09-13T05:50:01Z Includes bibliographical references (leaves 234-254). Significant effort has been put into the development of cost-effective abalone cultivation systems in South Africa, but the limited availability of suitable seaweed for abalone food is an obstacle to future development. The aim of this study was to investigate whether land-based integrated aquaculture (tank cultivation) and seaweed culture using Ulva lactuca in aquaculture effluent was feasible. This study was carried out at two abalone farms: Danger Point (I & J) (140 km east of Cape Town) and Jacobsbaai (JSP) (120 km north of Cape Town, South Africa). Both farms want to supplement the abalone feed with Ulva and investigate its potential for recirculation. Ulva is one of the simplest seaweeds to cultivate as it grows vegetatively. It would have a further benefit in its capacity to absorb nutrients and thus improve water quality of the aquaculture effluent. Results show that abalone effluent medium alone is insufficient for seaweed cultivation. Turbot effluent media has far more nutrients for seaweed but turbidity due to incomplete turbot feed pellet assimilation could be a problem. The most effective cultivation media on both farms is a fertilized effluent growth medium. This study established that water exchange rates are important in assuring an optimum nutrient supply for the seaweed. At high water exchange rates (20 Volume Exchanges (VE).d - Specific Growth Rate (SGR) in turbot and seawater treatments were not significantly different despite a significant difference in water nutrient concentration. Maximum nutrient removal occurs at both 12 and 20 volume exchanges per day, using a stocking denSity of 3 kgm-2 on both farms. Approximately 70 % of the ammonium is removed during the day and 60 % at night at JSP in both turbot and abalone treatments, while at I & J in the abalone treatments, 90 % and 80 % of the ammonium is removed during the day and night respectively. The diel fluctuation in dissolved oxygen is above critical levels (6 mg.l) for ... Master Thesis Turbot University of Cape Town: OpenUCT Danger Point ENVELOPE(-55.765,-55.765,52.383,52.383) |
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University of Cape Town: OpenUCT |
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ftunivcapetownir |
language |
English |
topic |
Botany |
spellingShingle |
Botany Robertson-Andersson, Deborah The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
topic_facet |
Botany |
description |
Includes bibliographical references (leaves 234-254). Significant effort has been put into the development of cost-effective abalone cultivation systems in South Africa, but the limited availability of suitable seaweed for abalone food is an obstacle to future development. The aim of this study was to investigate whether land-based integrated aquaculture (tank cultivation) and seaweed culture using Ulva lactuca in aquaculture effluent was feasible. This study was carried out at two abalone farms: Danger Point (I & J) (140 km east of Cape Town) and Jacobsbaai (JSP) (120 km north of Cape Town, South Africa). Both farms want to supplement the abalone feed with Ulva and investigate its potential for recirculation. Ulva is one of the simplest seaweeds to cultivate as it grows vegetatively. It would have a further benefit in its capacity to absorb nutrients and thus improve water quality of the aquaculture effluent. Results show that abalone effluent medium alone is insufficient for seaweed cultivation. Turbot effluent media has far more nutrients for seaweed but turbidity due to incomplete turbot feed pellet assimilation could be a problem. The most effective cultivation media on both farms is a fertilized effluent growth medium. This study established that water exchange rates are important in assuring an optimum nutrient supply for the seaweed. At high water exchange rates (20 Volume Exchanges (VE).d - Specific Growth Rate (SGR) in turbot and seawater treatments were not significantly different despite a significant difference in water nutrient concentration. Maximum nutrient removal occurs at both 12 and 20 volume exchanges per day, using a stocking denSity of 3 kgm-2 on both farms. Approximately 70 % of the ammonium is removed during the day and 60 % at night at JSP in both turbot and abalone treatments, while at I & J in the abalone treatments, 90 % and 80 % of the ammonium is removed during the day and night respectively. The diel fluctuation in dissolved oxygen is above critical levels (6 mg.l) for ... |
author2 |
Bolton, J Anderson, R J Probyn, T |
format |
Master Thesis |
author |
Robertson-Andersson, Deborah |
author_facet |
Robertson-Andersson, Deborah |
author_sort |
Robertson-Andersson, Deborah |
title |
The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
title_short |
The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
title_full |
The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
title_fullStr |
The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
title_full_unstemmed |
The cultivation of Ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
title_sort |
cultivation of ulva lactuca (chlorophyta) in an integrated aquaculture system, for the production of abalone feed and the bioremediation of aquaculture effluent |
publisher |
University of Cape Town |
publishDate |
2003 |
url |
http://hdl.handle.net/11427/6175 https://open.uct.ac.za/bitstream/11427/6175/1/thesis_sci_2003_robertson_andersson_d%20%281%29.pdf |
long_lat |
ENVELOPE(-55.765,-55.765,52.383,52.383) |
geographic |
Danger Point |
geographic_facet |
Danger Point |
genre |
Turbot |
genre_facet |
Turbot |
op_relation |
http://hdl.handle.net/11427/6175 https://open.uct.ac.za/bitstream/11427/6175/1/thesis_sci_2003_robertson_andersson_d%20%281%29.pdf |
_version_ |
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