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The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem

An investigation has been carried out on the particulate organic matter (IU-1) in suspension over the large inter-- and subtidal reef at Dalebrook in False Bay, standing stocks of hytoplankton, bacteria and detritus were monitored for 13 months, at three localities on the reef, on incoming and outgo...

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Main Author: Cliff, Geremy
Other Authors: Branch, George
Format: Thesis
Language:English
Published: Department of Biological Sciences 2023
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access_status_str Open Access
author Cliff, Geremy
author2 Branch, George
author_browse Branch, George
Cliff, Geremy
author_facet Branch, George
Cliff, Geremy
author_sort Cliff, Geremy
collection Thesis
description An investigation has been carried out on the particulate organic matter (IU-1) in suspension over the large inter-- and subtidal reef at Dalebrook in False Bay, standing stocks of hytoplankton, bacteria and detritus were monitored for 13 months, at three localities on the reef, on incoming and outgoing tides. A number of seasonal trends recharge, despite day-to-day variation in t."'1ese stocks. In spring and summer chlorophyll levels were la, 1 - 2 µg/1. Due to the extrerrely lcw nitrate concentrations ( < 2 µg at/1) and to a lesser extent, silicates ( < 6 µg at/1) , little autochthonous phytoplankton production was recorded over this period. Concentrations of nitrates, silicates and chlorcphyll a were highest at the offshore edge of the reef in incoming water. After a strong south-easterly win:i, chlorophyll concentrations of 19 µg/1 were rerorded O, 5 km offshore. Chlorophy 11 concentrations were in the region of 5 µg/1 in winter. Detritus accounted for aln'Ost 80% of the Pa1 and never dropped bela, O, 5 :rrg/1. There were no marked spatial and tidal influences on the mass of detritus in suspension. However, considerable import and export of material is believed to be associated with the strong water m,vements over the reef. Most of the detritus was in advanced stages of deconposition, making it extremely difficult to determine its origin. A Coulter Counter provided particle size spectra over the range 5 - 112 µm. It was found that particles with apparent diameters of 10 - 30 iirn contributed the highest volurre. Bacterial densities ranged fran 4 x 105 to 16 x 105 cells/ml; nurrbers were highest in late surmer and autumn. 95% of the cells were not attached to particles but were free in suspension. These results are canpared with those fran other inshore envirorurents.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:33:15.376Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2023
publishDateRange 2023
publishDateSort 2023
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/39000 The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem Cliff, Geremy Branch, George Zoology An investigation has been carried out on the particulate organic matter (IU-1) in suspension over the large inter-- and subtidal reef at Dalebrook in False Bay, standing stocks of hytoplankton, bacteria and detritus were monitored for 13 months, at three localities on the reef, on incoming and outgoing tides. A number of seasonal trends recharge, despite day-to-day variation in t."'1ese stocks. In spring and summer chlorophyll levels were la, 1 - 2 µg/1. Due to the extrerrely lcw nitrate concentrations ( < 2 µg at/1) and to a lesser extent, silicates ( < 6 µg at/1) , little autochthonous phytoplankton production was recorded over this period. Concentrations of nitrates, silicates and chlorcphyll a were highest at the offshore edge of the reef in incoming water. After a strong south-easterly win:i, chlorophyll concentrations of 19 µg/1 were rerorded O, 5 km offshore. Chlorophy 11 concentrations were in the region of 5 µg/1 in winter. Detritus accounted for aln'Ost 80% of the Pa1 and never dropped bela, O, 5 :rrg/1. There were no marked spatial and tidal influences on the mass of detritus in suspension. However, considerable import and export of material is believed to be associated with the strong water m,vements over the reef. Most of the detritus was in advanced stages of deconposition, making it extremely difficult to determine its origin. A Coulter Counter provided particle size spectra over the range 5 - 112 µm. It was found that particles with apparent diameters of 10 - 30 iirn contributed the highest volurre. Bacterial densities ranged fran 4 x 105 to 16 x 105 cells/ml; nurrbers were highest in late surmer and autumn. 95% of the cells were not attached to particles but were free in suspension. These results are canpared with those fran other inshore envirorurents. 2023-10-02T09:39:49Z 2023-10-02T09:39:49Z 1979 2023-10-02T09:08:59Z Master Thesis Masters MSc http://hdl.handle.net/11427/39000 eng application/pdf Department of Biological Sciences Faculty of Science
spellingShingle Zoology
Cliff, Geremy
The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem
thesis_degree_str Master's
title The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem
title_full The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem
title_fullStr The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem
title_full_unstemmed The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem
title_short The contribution by phytoplankton, bacteria and detritus to a rocky shore ecosystem
title_sort contribution by phytoplankton bacteria and detritus to a rocky shore ecosystem
topic Zoology
url http://hdl.handle.net/11427/39000
work_keys_str_mv AT cliffgeremy thecontributionbyphytoplanktonbacteriaanddetritustoarockyshoreecosystem
AT cliffgeremy contributionbyphytoplanktonbacteriaanddetritustoarockyshoreecosystem