Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat
Bibliography: leaves 122-142.
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Biological Sciences
2014
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613234771525632 |
|---|---|
| access_status_str | Open Access |
| author | Wynberg, Rachel |
| author_browse | Wynberg, Rachel |
| author_facet | Wynberg, Rachel |
| author_sort | Wynberg, Rachel |
| collection | Thesis |
| description | Bibliography: leaves 122-142. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/8398 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:54.720Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| 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:11427/8398 The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat Wynberg, Rachel Zoology Bibliography: leaves 122-142. The ecological effects of collecting the sandprawn Callianassa kraussi and the mudprawn Upogebia africana for bait were assessed at Langebaan Lagoon, South Africa, through surveys, observations and long-term experimental analyses. While only a small proportion of the prawns is removed from the lagoon annually, amounting to no more than 0.01 for the total lagoon, the physical disturbance inflicted by collecting is likely to be more detrimental and longer-lived than the actual removal of the prawns. Bait-collecting activities are concentrated on the centre sandbanks where some 400 000 prawns are removed annually - less than 5 of the total prawn population on these sandbanks. In terms of numbers removed, bait-collecting is thus no threat to the prawn populations at Langebaan Lagoon although there are signs that sandprawn densities and modal body sizes have been reduced in areas of intense bait-collecting activities. Massive quantities of sediment are disturbed through bait-collecting activities and this, inadvertently, results in the disturbance of other components of the biota. It is estimated that approximately 543 g of macrofauna are disturbed with each bag limit of prawns (50) removed, amounting to approximately 10 000 kg of macrofauna being disturbed annually. While the fate of this macrofauna is not completely determined, approximately 80 is subsequently preyed upon by scavenging gulls. The long-term effects of high-intensity disturbance on the biota of a sandflat were assessed through simulated bait-collecting activities, viz "digging" and "sucking" for C. kraussi and U. africana. The recovery of both C. kraussi and U. africana was far more protracted than predicted - probably being completed only 18 months after the initial disturbance. Meiofaunal and macrofaunal numbers decreased immediately following the initial disturbance. 2014-10-11T12:19:30Z 2014-10-11T12:19:30Z 1991 Master Thesis Masters MSc http://hdl.handle.net/11427/8398 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Zoology Wynberg, Rachel The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat |
| thesis_degree_str | Master's |
| title | The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat |
| title_full | The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat |
| title_fullStr | The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat |
| title_full_unstemmed | The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat |
| title_short | The ecological effects of collecting Callianassa kraussi Stebbing and Upogebia africana (Ortmann) for bait : impacts on the biota of an intertidal sandflat |
| title_sort | ecological effects of collecting callianassa kraussi stebbing and upogebia africana ortmann for bait impacts on the biota of an intertidal sandflat |
| topic | Zoology |
| url | http://hdl.handle.net/11427/8398 |
| work_keys_str_mv | AT wynbergrachel theecologicaleffectsofcollectingcallianassakraussistebbingandupogebiaafricanaortmannforbaitimpactsonthebiotaofanintertidalsandflat AT wynbergrachel ecologicaleffectsofcollectingcallianassakraussistebbingandupogebiaafricanaortmannforbaitimpactsonthebiotaofanintertidalsandflat |