Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Modelling and managing the effects of trout farms on Cape rivers
Bibliography: pages 162-175.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Biological Sciences
2016
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613206085632000 |
|---|---|
| access_status_str | Open Access |
| author | Brown, Catherine Anne |
| author2 | King, Jackie |
| author_browse | Brown, Catherine Anne King, Jackie |
| author_facet | King, Jackie Brown, Catherine Anne |
| author_sort | Brown, Catherine Anne |
| collection | Thesis |
| description | Bibliography: pages 162-175. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/21710 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:27.580Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| 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:11427/21710 Modelling and managing the effects of trout farms on Cape rivers Brown, Catherine Anne King, Jackie Field, John G Zoology Bibliography: pages 162-175. The south-western Cape is currently responsible for 45% of the total annual trout production in South Africa and further expansion of this industry in the region is likely. A pilot study of seven trout farms situated on the upper reaches of rivers in the south-western Cape was undertaken to determine whether there was a common trend in their effect on the rivers. Results indicated that the impact of the farms on the benthic invertebrate communities of the rivers ranged from mild to severe, based on the degree of change in the structure of the communities form upstream to downstream of the effluent outlets. Those farms situated on mountain streams had the greatest impact and those on the downstream foothill had a lesser impact. The reduced impact in the foothill zone was probably because these reaches were already disturbed by other catchment activities. Of the three farms that were situated on mountain streams and source areas, two used plastic portapools and the third earth dams. There was a substantial increase in the number of oligochaetes downstream of both 'portapool' farms and yet, despite being situated in the same sensitive river zone, this did not occur downstream of the farm that used earth dams. The general impact of trout farm effluent on the mountain-stream and source zones was to eliminate or greatly reduce the number of Limnichidae, Helodidae, Plecoptera, Elmidae, Heptageniidae and Ephemerellidae, and, in the case of portapool farms, to replace these with Naididae, Lumbriculidae, Chironomidae and Planaria. Once-off chemical samples were also collected at each site and, acknowledging the limitations of the sampling strategy, results showed that the particulate fraction of the effluent was probably responsible for the recorded reaction of the biota. 2016-09-06T14:47:53Z 2016-09-06T14:47:53Z 1998 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/21710 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Zoology Brown, Catherine Anne Modelling and managing the effects of trout farms on Cape rivers |
| thesis_degree_str | Doctoral |
| title | Modelling and managing the effects of trout farms on Cape rivers |
| title_full | Modelling and managing the effects of trout farms on Cape rivers |
| title_fullStr | Modelling and managing the effects of trout farms on Cape rivers |
| title_full_unstemmed | Modelling and managing the effects of trout farms on Cape rivers |
| title_short | Modelling and managing the effects of trout farms on Cape rivers |
| title_sort | modelling and managing the effects of trout farms on cape rivers |
| topic | Zoology |
| url | http://hdl.handle.net/11427/21710 |
| work_keys_str_mv | AT browncatherineanne modellingandmanagingtheeffectsoftroutfarmsoncaperivers |