List of Titles

Policies to reduce single-use plastic marine pollution in West Africa:

- Adam, Issahaku, Walker, Tony R, Bezerra, Joana C, Clayton, Andrea

Authors: Adam, Issahaku , Walker, Tony R , Bezerra, Joana C , Clayton, Andrea
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/150196 , vital:38948 , https://doi.org/10.1016/j.marpol.2020.103928
Description: Countries in Africa are increasingly adopting policies to reduce single-use plastic (SUP) pollution, yet there has been limited analysis of policies adopted by African countries. This paper reviews SUP reduction policies, specifically in West Africa.
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Date Issued: 2020

Deposition of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shells around CdSeTe alloyed core quantum dots: effects on optical properties

- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C

Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
Date: 2015
Language: English
Type: Article
Identifier: vital:7289 , http://hdl.handle.net/10962/d1020342
Description: In this work, we synthesized water-soluble L-cysteine-capped alloyed CdSeTe core quantum dots (QDs) and investigated the structural and optical properties of deposition of each of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shell layers. Photophysical results showed that the overcoating of a CdS shell around the alloyed CdSeTe core [quantum yield (QY) = 8.4%] resulted in effective confinement of the radiative exciton with an improved QY value of 93.5%. Subsequent deposition of a ZnSe shell around the CdSeTe/CdS surface decreased the QY value to 24.7%, but an increase in the QY value of up to 49.5% was observed when a ZnS shell was overcoated around the CdSeTe/CdS/ZnSe surface. QDs with shell layers showed improved stability relative to the core. Data obtained from time-resolved fluorescence measurements provided useful insight into variations in the photophysical properties of the QDs upon the formation of each shell layer. Our study suggests that the formation of CdSeTe/CdS core/shell QDs meets the requirements of quality QDs in terms of high photoluminescence QY and stability, hence further deposition of additional shells are not necessary in improving the optical properties of the core/shell QDs. Copyright © 2015 John Wiley & Sons, Ltd. , Original publication is available at http://dx.doi.org/10.1002/bio.3013
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Date Issued: 2015

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Partial Purification and Characterization of Endoxylanase from a fungus, Leohumicola incrustata

- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F

Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
Date: 2021
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/440393 , vital:73779 , 10.4314/br.v19i1.2
Description: Xylanases are glycoside hydrolases (GH) that degrade β-1, 4-xylan, a linear polysaccharide found as hemicellulose in cell wall of plants. Endoxylanase (Endo-1, 4-β-xylanase, EC 3.2. 1.8) randomly catalyses xylan to produce varying short xylooligosaccharides (XOS). This study aimed to determine the characteristics of a partially purified endoxylanase from Leohumicola incrustata. Enzyme production was carried out using beechwood (BW) xylan, after which the cell-free crude filtrate was concentrated using the ammonium sulphate precipitation method. The hydrolysed products were analysed by thin-layer chromatography (TLC) and zymography. The result showed that the enzyme produced varying smaller-sized linear xylooligosaccharides with R f values corresponding to those of xylobiose, xylotriose, xylotetraose, xylopentaose, xylohexaose and other higher oligomers. The endoxylanase had a molecular mass of 72 kDa. The enzyme is stable in the presence of K+, Na+, Ca 2+, Fe 2+, Mg 2+, Zn 2+, Co 2+, pH of 5.0 and temperature of 37 o C. However, the activity gradually decreased after 60 min at 50 o C and retained over 69% activity after 120 min, while at 60 and 70 o C, the enzyme activity sharply decreased (pre-incubation periods). Endoxylanase from L. incrustata is comparable to those of other microorganisms and should be considered an attractive candidate for future industrial applications.
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Date Issued: 2021

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Purification and characterization of an amyloglucosidase from an ericoid mycorrhizal fungus (Leohumicola incrustata)

- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F

Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
Date: 2018
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/440405 , vital:73780 , https://doi.org/10.1186/s13568-018-0685-1
Description: This study aimed to purify and characterize amyloglucosidase (AMG) from Leohumicola incrustata. AMG was purified to homogeneity from cell-free culture filtrate of an ERM fungus grown in a modified Melin–Norkrans liquid medium. The molecular mass of the AMG was estimated to be 101 kDa by combining the results of Sephadex G-100 gel filtration, sodium dodecyl sulphate–polyacrylamide gel electrophoresis, and zymography. The Km and kcat values were 0.38 mg mL−1 and 70 s−1, respectively, using soluble starch as a substrate. The enzyme was stable at 45 °C (pH 5.0), retaining over 65% activity after a pre-incubation period of 24 h. The metal inhibition profile of the AMG showed that Mn2+ and Ca2+ enhanced activity, while it was stable to metals ions, except a few (Al3+, Co2+, Hg2+ and Cd2+) that were inhibitory at a concentration higher than 5 mM. Thin layer chromatography revealed that only glucose was produced as the product of starch hydrolysis. The amylase from L. incrustata is a glucoamylase with promising characteristics such as temperature stability over an extended period, high substrate affinity and stability to a range of chemicals. Also, this study reports for the first time the possibility of using some culturable ERM fungi to produce enzymes for the bio-economy.
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Date Issued: 2018

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AIA's Southern Africa Chronicle - Volume VIII No.1

- Africa Information Afrique (AIA)

Authors: Africa Information Afrique (AIA)
Date: 1995
Subjects: AIA
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/169377 , vital:41744
Description: Sowa, January 3, 1994 (AIA/Caitlin Davies) — Mercy Manakedi Theetso is 29 and has four children. She breast-fed her first child for 18 months, her second for eight months, and she didn’t breast-feed her third child at all. “I was working and the baby stayed with my mother so we used a bottle for the first four months, then we used a cup,” explains Theetso. “Myself, I like to breast-feed but I don’t have the time.” In the 1960s Botswana’s medical practitioners began giving new-born babies the bottle. Now, 30 years later, there is a concerted effort by the Botswana government to promote a return to breast-feeding. But as women have gone out of the home to work, reversing the trend is not an easy task. However, breast-feeding does remain popular in Botswana. “It’s a culturally acceptable norm,” says Virkloti Morewane of UNICEF, and boys and girls are fed for the same amount of time.
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Date Issued: 1995

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Linguistic Dominance and Translanguaging Language: Issues in Generations: The Legacy

- Aiseng, Kealeboga

Authors: Aiseng, Kealeboga
Date: 2022
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/455230 , vital:75414 , https://doi.org/10.3389/fcomm.2022.880452
Description: The use of language(s) in media is very important as it can determine inclusion or exclusion. As such, the use of language in the media is contentious. This paper traces two language issues in one of the SABC's longest-running soap operas, Generations: The Legacy, lan-guage ideology and a tool against that language ideology. The former refers to a linguistic dominance of isiZulu and the latter refers to translanguaging. With the use of transcription data analysis and audio-visual analysis, the current study has concluded that there are issues of linguistic dominance and translanguaging in Generations: The Legacy. These language issues are perpetuated through the narrative and characters of the story. The appropriate theoretical framework for this paper is the use of language in popular culture, with the view that the use of languages in popular culture can exclude and include, can em-power, and disempower. Focusing on the dialogues of the soap using selected episodes as case studies for analysis, the study has also con-cluded that creative decisions made in the soap are ideological. These findings raise questions about the use of media to perpetuate certain language ideologies and raise questions about whose interests are served by these language ideologies and how to fight these language ideologies.
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Date Issued: 2022

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Accelerated sludge solubilisation under sulphate reducing conditions: the effect of hydrolytic enzymes on sludge floc size distribution and EPS composition

- Akhurst, P, Rose, Peter D, Whiteley, Chris G, Pletschke, Brett I

Authors: Akhurst, P , Rose, Peter D , Whiteley, Chris G , Pletschke, Brett I
Date: 2002
Language: English
Type: Conference paper
Identifier: vital:6455 , http://hdl.handle.net/10962/d1010430
Description: Extracellular polymeric substances (EPS) are the construction materials for microbial aggregates such as biofilms, flocs and sludge, and greatly contribute to the structural integrity of sludge flocs in wastewater treatment processes. The loss of integrity of the sewage sludge floc is believed to be due to enhanced hydrolysis of important structural components such as lignin, protein and cellulose in the sludge floc matrix. The mechanism of enhanced sludge floc fracture, due to the action of enzymes hydrolysing these structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate reducing system is compromised. A range of relatively non-specific exogenous enzymes (ß-glucosidase, cellulase, proteases: trypsin, pronase E and chymotrypsin) were added to a sulphidogenic bioreactor- (containing both sulphate reducing bacteria (SRB) and a methanogenic bacterial system) and a (control) methanogenic bioreactor sample, and the effect of these enzymes on sludge floc size (diameter) distribution and EPS composition was investigated. Sludge samples from the bioreactors were examined under bright field and differential interference contrast light microscopy. Proteolytic and glucohydrolytic activity of the enzymes were monitored using standard enzyme assaying techniques, and Bradford, Somogyi-Nelson, and total carbohydrate assays were performed to establish the composition of the EPS (after extraction with 3% (v/v) glutaraldehyde and Sephacryl S-400 size exclusion chromatography). Sludge flocs present in the sulphidogenic environment of the sulphidogenic bioreactor were found to have smaller diameters than their counterparts present in the methanogenic bioreactor. The addition of hydrolytic (i.e. proteolytic and glycohydrolytic) enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and deflocculation. The presence of ß-glucosidase, cellulase, and proteases naturally residing within the sludge floc was confirmed. We propose that the addition of commercially available enzymes may be prohibitively costly on a large scale, and that the activity of the enzymes naturally residing within the floc matrix be optimised or enhanced. As the bulk of the EPS was shown to be composed of mainly polysaccharides, we propose that by increasing the activity of the naturally occurring ß-glucosidases residing within the floc matrix, the process of deflocculation may be enhanced. As sulphide has been shown to increase the activity of this very important key enzyme, we propose that this is one of the contributing factors why sludge solubilisation is accelerated under sulphate reducing conditions.
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Date Issued: 2002

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Framing of political leaders during the# BringBackOurGirls campaign by the Nigerian Press: a comparative study of Guardian and Vanguard Newspapers

- Akpojivi, Ufuoma, Aiseng, Kealeboga

Authors: Akpojivi, Ufuoma , Aiseng, Kealeboga
Date: 2022
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/455214 , vital:75413 , https://doi.org/10.3389/fcomm.2022.853673
Description: This study examines Nigeria's political leaders' framing during the #BringBackOurGirls movement campaign using two selected national newspapers in Nigeria, i.e., the Guardian and the Vanguard newspa-pers. Using 46 news stories culled during the periods of April 14, 2014, to June 14, 2014, and May 29, 2015, to July 29, 2015, which represent two significant eras, i.e., when the schoolgirls were abducted, and when there was a change in government, the study argued that four frames of government failure, the desperation of citizens, politicization of gov-ernment actions and heroism were dominant in both presses reportage. During the first period of study, both presses were critical of President Goodluck Jonathan and his inability to secure the release of the ab-ducted Chibok schoolgirl as they used frames of “liar”, “clueless”, and “failure” amongst others to characterize his government actions and in-actions. However, during the second study period, both presses were less critical of President Buhari as they ascribed the “hero” frame to him due to his vast military experience. Nevertheless, the ideological posi-tion of both newspapers influenced their reportage as Guardian news stories provided depth analysis, while Vanguard newspaper stories lacked depth.
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Date Issued: 2022

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Standard Practices

- Amendt, Jens, Anderson, G, Campobasso, Carlo P, Dadour, I R, Gaudry, E, Hall, Martin J R, Moretti, T C, Sukontason, K L, Villet, Martin H

Authors: Amendt, Jens , Anderson, G , Campobasso, Carlo P , Dadour, I R , Gaudry, E , Hall, Martin J R , Moretti, T C , Sukontason, K L , Villet, Martin H
Date: 2015
Subjects: To be catalogued
Language: English
Type: text , book chapter
Identifier: http://hdl.handle.net/10962/442821 , vital:74036 , ISBN , https://www.routledge.com/Forensic-Entomology-International-Dimensions-and-Frontiers/Tomberlin-Benbow/p/book/9780367575885
Description: The use of forensic entomology has become established as a global science. Recent efforts in the field bridge multiple disciplines including, but not limited to, microbiology, chemistry, genetics, and systematics as well as ecology and evolution. The first book of its kind, Forensic Entomology: International Dimensions and Frontiers provides an inclusive summary of worldwide research on this body of knowledge that integrates aspects of a wide range of scientific realms. The book first reviews the history of forensic entomology, its accomplishments, and future challenges in nations around the world. It then provides perspectives of other scientific disciplines that are shaping the questions being addressed in the field.
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Date Issued: 2015

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Recommendations for the future of recreational fisheries to prepare the social‐ecological system to cope with change

- Arlinghaus, Robert, Cooke, Steven J, Sutton, S G, Danylchuk, A J, Potts, Warren M, Freire, K D M, Alós, J, Da Silva, E T, Cowx, Ian G, Van Anrooy, R

Authors: Arlinghaus, Robert , Cooke, Steven J , Sutton, S G , Danylchuk, A J , Potts, Warren M , Freire, K D M , Alós, J , Da Silva, E T , Cowx, Ian G , Van Anrooy, R
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125810 , vital:35819 , https://doi.10.1111/fme.12191
Description: This paper presents conclusions and recommendations that emerged from the 7th World Recreational Fishing Conference (WRFC) held in Campinas, Brazil in September 2014. Based on the recognition of the immense social and economic importance of recreational fisheries coupled with weaknesses in robust information about these fisheries in many areas of the world, particularly in many economies in transition, it is recommended to increase effort to build effective governance arrangements and improve monitoring and assessment frameworks in data-poor situations. Moreover, there is a need to increase interdisciplinary studies that will foster a systematic understanding of recreational fisheries as complex adaptive social-ecological systems. To promote sustainable recreational fisheries on a global scale, it is recommended the detailed suggestions for governance and management outlined in the United Nations Food and Agricultural Organization Technical Guidelines for Responsible Fisheries: Recreational Fisheries are followed.
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Date Issued: 2016

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Customary management as TURFs: social challenges and opportunities

- Aswani, Shankar

Authors: Aswani, Shankar
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/145403 , vital:38435 , DOI: 10.5343/bms.2015.1084
Description: There is a growing interest in working with customary management (CM) systems to effectively manage benthic resources and small-scale fisheries. The underlying notion is that CM institution as territorial use rights in fisheries (TURFs) can be sufficiently adaptive and dynamic to create the local incentives that are necessary for promoting sustainable fishing practices and marine conservation more generally in a given region. This paper reviews the social opportunities and challenges of working with CM systems as a form of TURF, particularly in Oceania. A key conclusion is that policy makers and managers not only need to recognize natural interconnectivity in any one marine space, but also consider the social interconnectivity of stakeholders that covers customary TURFs. Only by recognizing and working with the existing social networks that overlay any given marine territory can the operational principles of CM (as reviewed in this paper) be effectively deployed for achieving some kind of bioeconomic efficiency and creating an equitable rights-based fisheries management system.
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Date Issued: 2017

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Natural enemies from South Africa for biological control of Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae) in Europe

- Baars, Jan-Robert, Coetzee, Julie A, Martin, Grant D, Hill, Martin P, Caffrey, J M

Authors: Baars, Jan-Robert , Coetzee, Julie A , Martin, Grant D , Hill, Martin P , Caffrey, J M
Date: 2010
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/76914 , vital:30637 , https://doi.org/10.1007/s10750-010-0427-0
Description: The non-native invasive plant, Lagarosiphon major (Hydrocharitaceae) is a submersed aquatic macrophyte that poses a significant threat to water bodies in Europe. Dense infestations prove difficult to manage using traditional methods. In order to initiate a biocontrol programme, a survey for natural enemies of Lagarosiphon was conducted in South Africa. Several phytophagous species were recorded for the first time, with at least three showing notable promise as candidate agents. Amongst these, a leaf-mining fly, Hydrellia sp. (Ephydridae) that occurred over a wide distribution causes significant leaf damage despite high levels of parasitism by braconid wasps. Another yet unidentified fly was recorded mining the stem of L. major. Two leaf-feeding and shoot boring weevils, cf. Bagous sp. (Curculionidae) were recorded damaging the shoot tips and stunting the growth of the stem. Several leaf-feeding lepidopteran species (Nymphulinae) were frequently recorded, but are expected to feed on a wide range of plant species and are not considered for importation before other candidates are assessed. The discovery of several natural enemies in the country of origin improves the biological control prospects of L. major in Europe.
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Date Issued: 2010

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SASO and Black Consciousness, and the shift to congress politics

- Badat, Saleem

Authors: Badat, Saleem
Date: 2016
Language: English
Type: book chapter , text
Identifier: http://hdl.handle.net/10962/59755 , vital:27645 , http://witspress.co.za/catalogue/students-must-rise/
Description: Students Must Rise 98 Chapter 8 SASO and Black Consciousness, and the shift to congress politics I n 1960, demonstrators protesting against pass laws were killed and injured by police at Sharpeville. Soon afterwards, the apartheid government declared a state of emergency. Over 11 000 political activists were detained, and repressive new laws, police raids, arrests, bannings, and torture were used to crush political opposition to apartheid. The African National Congress (ANC) and Pan Africanist Congress (PAC) were banned, and many leaders of the ANC and PAC were arrested and imprisoned , and hundreds fled into exile. For many white South Africans, the rest of the 1960s were a time of economic boom, political calm, prosperity, and rising living standards. Some blacks took the opportunity to accumulate wealth, power, and privilege through the Bantustans that the apartheid government established as part of its separate development programme. For most blacks, it was a period of great economic exploitation, extensive political and social control, fear, and demoralisation. It was difficult to see how there could be any political challenge to white minority rule. Anti-apartheid organisations faced immediate repression. They also had to overcome black people’s fear and demoralisation, which stood in the way of mobilising opposition against apartheid. The emergence of the South African Students’ Organisation and Black Consciousness Despite many problems, the South African Students’ Organisation (SASO) was formed as an exclusively black university and college student organisation in 1968. It escaped immediate state repression, and developed a following among students at the Saleem Badat SASO and Black Consciousness, and the shift to congress politics 99 universities reserved for blacks. Thereafter, the ideology of Black Consciousness (BC) was developed and other BC organisations were formed, resulting in the BC movement. SASO saw its challenge as the ‘assertion, manifestation and development of a sense of awareness politically, socially and economically among the black community’.1 It emphasised black ‘group cohesion and solidarity’ as ‘important facets of Black Consciousness’, the need for ‘the totality of involvement of the oppressed people’, and for BC ‘to be spread to reach all sections of the black community’.2 SASO began community development, literacy, education, media, culture, and sports projects, which aimed to help black communities to determine and realise their own needs. They were seen as a means to win the trust of people and to educate and mobilise them.3 Projects instilled the idea of self-reliance, seen as important for achieving freedom, in members and communities. SASO created a favourable political climate for various organisations to emerge.
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Date Issued: 2016

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Inferring direct DNA binding from ChIP-seq

- Bailey, Timothy L, Machanick, Philip

Authors: Bailey, Timothy L , Machanick, Philip
Date: 2012
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/439314 , vital:73565 , https://doi.org/10.1093/nar/gks433
Description: Genome-wide binding data from transcription factor ChIP-seq experiments is the best source of information for inferring the relative DNA-binding affinity of these proteins in vivo . However, standard motif enrichment analysis and motif discovery approaches sometimes fail to correctly identify the binding motif for the ChIP-ed factor. To overcome this problem, we propose ‘central motif enrichment analysis’ (CMEA), which is based on the observation that the positional distribution of binding sites matching the direct-binding motif tends to be unimodal, well centered and maximal in the precise center of the ChIP-seq peak regions. We describe a novel visualization and statistical analysis tool—CentriMo—that identifies the region of maximum central enrichment in a set of ChIP-seq peak regions and displays the positional distributions of predicted sites. Using CentriMo for motif enrichment analysis, we provide evidence that one transcription factor (Nanog) has different binding affinity in vivo than in vitro , that another binds DNA cooperatively (E2f1), and confirm the in vivo affinity of NFIC, rescuing a difficult ChIP-seq data set. In another data set, CentriMo strongly suggests that there is no evidence of direct DNA binding by the ChIP-ed factor (Smad1). CentriMo is now part of the MEME Suite software package available at http://meme.nbcr.net . All data and output files presented here are available at: http://research.imb.uq.edu.au/t.bailey/sd/Bailey2011a .
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Date Issued: 2012

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Coming to terms with the "Border War" in post-apartheid South Africa

- Baines, Gary F

Authors: Baines, Gary F
Date: 2008
Language: English
Type: Conference paper
Identifier: vital:6157 , http://hdl.handle.net/10962/d1007077
Description: If you are a white, male South African between the ages of about 35 and 60 it is very likely that you donned the nutria brown uniform of the South African Defence Force (SADF). Between 1967 and 1994 approximately 300 000 young white males were conscripted by the SADF. As far as most of these conscripts were concerned, there was no option other than heeding the call-up and performing national service or diensplig. Failure to do so meant harsh penalties. The alternatives were to object on conscientious (actually religious) grounds and face a six year jail sentence, or flee the country. And the obligation did not end with national service as conscripts were assigned to citizen force or commando units that were liable for periodical call-ups for camps that might have included deployment in the “operational areas” from 1974 or tours of duty in the black townships from 1984. Those - like myself - belonging to this national service generation were part-time soldiers for much of their adult lives. Most served willingly, some with patriotic fervour. Others did so reluctantly and with little enthusiasm.
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Date Issued: 2008

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Commentary: Negotiating distant influences: globalization and broadcasting policy reforms in Zambia and South Africa

- Banda, Fackson

Authors: Banda, Fackson
Date: 2006
Language: English
Type: text , article
Identifier: vital:6325 , http://hdl.handle.net/10962/d1008299 , https://doi.org/10.22230/cjc.2006v31n2a1785
Description: preprint , This commentary looks at the influences of globalisation on broadcasting policy reforms in Zambia and South Africa, with specific focus on such processes as deregulation, privatisation, commercialisation, communitarianism and technological convergence. It concludes that globalisation does not affect southern African countries uniformly; rather, it is refracted in accordance with the different cultural and political experiences of such countries.
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Date Issued: 2006

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Variations in moult, morphology, movement and survival rates of the Sombre Greenbul Andropadus importunus within southern Africa

- Bonnevie, Bo T

Authors: Bonnevie, Bo T
Date: 2014
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/448368 , vital:74725 , https://doi.org/10.2989/00306525.2014.902403
Description: Ringing data from the South African bird ringing unit, SAFRING, were analysed to explore variations and trends in population parameters of the Sombre Greenbul Andropadus importunus in southern Africa. Adult and juvenile body mass increased southwards, whereas the relative sizes of wings and bills decreased southwards. Recapture and recovery data indicated that adults have very high site fidelity and suggested that juvenile dispersal is limited. The annual survival rate of adults was on average more than twice that of juveniles and there was little regional variation within either age group. The onset of primary wing moult became progressively later northwards, but the duration of moult did not vary significantly with latitude. Juveniles started their first normally descendent wing moult sequence about one month after adults.
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Date Issued: 2014

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Incorporating the spatial component of fisheries data into stock assessment models

- Booth, Anthony J

Authors: Booth, Anthony J
Date: 2000
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/124800 , vital:35698 , https://doi.10.1006/jmsc.2000.0816
Description: Fisheries-dependent and independent data have a strong spatial component. These data are also multi-dimensional, making them difficult to visualize and analyze, prompting the use of spatial analysis to facilitate an understanding of their relationships. One aspect of fisheries data that is often ignored is the distribution and abundance of a particular resource and the fishing patterns of its harvesting fisheries. In order to improve management advice, stock assessors need to incorporate the spatial component of these data into an existing assessment framework. This paper presents a three-dimensional visualization of the age-structure and fishery dependent and independent data associated with the sparid fish Pterogymnus laniarius on the Agulhas Bank, South Africa. A spatially-referenced spawner biomass per-recruit model is developed to illustrate the applicability of incorporating spatially referenced information in providing management advice. The model provided evidence that, even on a spatial scale, fishing mortality is significantly correlated to fishing effort. Areas of high levels of spawner biomass are noted, all of which corresponded to those geographic areas with a combination of low fishing effort and high adult biomass.
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Date Issued: 2000

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