Population status of 14 shark species caught in the protective gillnets off KwaZulu - Natal beaches, South Africa, 1978 - 2003

2006 ◽  
Vol 57 (2) ◽  
pp. 225 ◽  
Author(s):  
Sheldon F. J. Dudley ◽  
Colin A. Simpfendorfer
Keyword(s):  
South Africa ◽  
Potential Effect ◽  
Catch Rate ◽  
Population Increase ◽  
Shark Species ◽  
Population Status ◽  
Carcharhinus Leucas ◽  
Kwazulu Natal ◽  
Carcharhinus Obscurus ◽  
Catch Rates

Shark nets have been set off the beaches of KwaZulu–Natal, South Africa, since 1952 to reduce the risk of shark attack. The nets fish in fixed localities 400 m from shore and both directly affect local shark populations and act as fisheries-independent monitoring devices. Reliable catch information at the species level was available for the period 1978–2003. Trends in catch rate and size were used to assess the population status of 14 commonly caught shark species. In addition, a demographic modelling approach was used in conjunction with the catch information to assess the potential effect of the nets on populations. Catch rates of four species (Carcharhinus leucas, C. limbatus, Sphyrna lewini and S. mokarran) showed a significant decline, as did the mean or median length of three species (Carcharhinus amboinensis, C. limbatus and female Carcharodon carcharias). For three species that showed declining catch rates or length the potential effect of the shark nets was assessed to be low, suggesting that other sources of catch were responsible for the declining status. The potential effect of the shark nets was assessed to be high for two species (Carcharhinus obscurus and Carcharias taurus, neither of which showed declines in catch rate or length), because of very low intrinsic rates of population increase.

Shark control: experimental fishing with baited drumlines

1998 ◽  
Vol 49 (7) ◽  
pp. 653 ◽  
Author(s):  
S. F. J. Dudley ◽  
R. C. Haestier ◽  
K. R. Cox ◽  
M. Murray
Keyword(s):  
Optimal Solution ◽  
Control Programme ◽  
Shark Species ◽  
Gill Nets ◽  
Carcharhinus Leucas ◽  
Local Reduction ◽  
Shark Attacks ◽  
By Catch ◽  
Catch Rates ◽  
Physical Environmental Factors

Protective gill-nets (shark nets) have been successful in reducing the frequency of shark attacks on the coast of KwaZulu-Natal (KZN), South Africa, since 1952. This is achieved primarily through a local reduction in numbers of large sharks. Yet the nets are non-selective in terms of shark species caught and take a by-catch of dolphins, sea turtles, batoids and teleosts. Baited lines, or drumlines, as used in the Queensland shark control programme, were tested as possible alternatives to gill-nets. They demonstrated greater species selectivity for sharks and also a reduced by-catch of non-shark animals. The shark catch included the three species responsible for most shark attacks on the KZN coast, Carcharhinus leucas, Galeocerdo cuvier and Carcharodon carcharias. The probability of the bait being scavenged, or a shark being caught, was modelled in relation to a number of physical environmental factors. Although there was insufficient variability in the effort data for a quantitative comparison of catch rates between nets and drumlines, the results suggested that an optimal solution may be to deploy a combination of nets and drumlines.

scholarly journals Patterns in abundance and size of sharks in northwestern Australia: cause for optimism

2019 ◽  
Vol 77 (1) ◽  
pp. 72-82
Author(s):  
Matias Braccini ◽  
Brett Molony ◽  
Nick Blay
Keyword(s):  
Life Histories ◽  
Shark Species ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Study Region ◽  
Scalloped Hammerhead ◽  
Carcharhinus Obscurus ◽  
Northwestern Australia ◽  
Mean Size ◽  
Catch Rates

Abstract Reliable information for population assessments is rare for sharks. We quantified patterns in catch rates and mean size for numerous tropical and subtropical species from 15 years of fishery-independent surveys (2002–2017) in northwestern Australia. This study region represents an area of ~0.8 million km2 which was closed to commercial shark fishing from 1993 or 2005 onward due to the very high State-wide catches of sandbar (Carcharhinus plumbeus) and dusky (Carcharhinus obscurus) sharks. A total of 43 shark and ray species were sampled, with sandbar shark being the most commonly caught species, followed by milk (Rhizoprionodon acutus), spot-tail (Carcharhinus sorrah), tiger (Galeocerdo cuvier), blacktip (Carcharhinus limbatus and Carcharhinus tilstoni), dusky and sliteye (Loxodon macrorhinus) sharks, and scalloped hammerhead (Sphyrna lewini). For sandbar shark, catch rates increased between 2008 and 2017 whereas for other taxa catch rates were mostly stable (albeit fluctuating). Mean size at capture fluctuated across years with no particular trends. Unlike for other parts of the world, catch rates and mean size of northwestern Australian sharks have been stable or increased in recent years. Though most shark species have conservative life histories, when science, management and enforcement work synergistically, sustainable resource use, recovery and conservation outcomes can all be achieved.

Nursery grounds, movement patterns and growth rates of dusky sharks, Carcharhinus obscurus: a long-term tag and release study in South African waters

2009 ◽  
Vol 60 (6) ◽  
pp. 571 ◽  
Author(s):  
Nigel E. Hussey ◽  
Ian D. McCarthy ◽  
Sheldon F. J. Dudley ◽  
Bruce Q. Mann
Keyword(s):  
South African ◽  
Growth Rates ◽  
Movement Patterns ◽  
Small Scale ◽  
Shark Species ◽  
Early Life Stages ◽  
Kwazulu Natal ◽  
Management Plans ◽  
Carcharhinus Obscurus

Knowledge of movement patterns of sharks in coastal waters is critical for the structuring of regional management plans. Through a long-term tag–recapture program, 9716 dusky sharks (Carcharhinus obscurus) were tagged and released along the east coast of South Africa. A total of 648 C. obscurus, principally small sharks (<100 cm PCL), were recaptured. Most recaptures were within 100 km of the tagging location in the nursery habitat in KwaZulu-Natal (KZN) with small scale movements occurring throughout the year. Forty-eight C. obscurus undertook movements >200 km that indicated a southerly migration between KZN and Eastern/Southern Cape (E/SC) between June and November. Seasonal northerly migrations were less well defined. The largest southerly and northerly movements were 1323 km and 1374 km, respectively. For sharks moving 1–100 km south from their tagging locality in KZN, an increase in displacement occurred between June and September identifying animals beginning their migration to the E/SC. With increasing displacement, there was also an increase in minimum swimming speed. Calculated growth rates of small sharks of 10.3–11.5 cm year–1 were in agreement with current literature values. Established tag–recapture programs provide an important tool in understanding the ecology of early life-stages of coastal shark species.

scholarly journals Reducing the environmental impact of shark-control programs: a case study from KwaZulu-Natal, South Africa

2011 ◽  
Vol 62 (6) ◽  
pp. 700 ◽  
Author(s):  
Geremy Cliff ◽  
Sheldon F. J. Dudley
Keyword(s):  
South Africa ◽  
Large Scale ◽  
Shark Species ◽  
Control Programs ◽  
The Past ◽  
South Wales ◽  
Kwazulu Natal ◽  
Shark Attacks ◽  
By Catch

Large-scale shark-control programs at popular beaches in New South Wales and Queensland, Australia, and KwaZulu-Natal (KZN), South Africa, provide protection against shark attack. Although these programs have enhanced bathing safety, reducing the environmental impacts of decades of fishing for large sharks and the associated by-catch remains a challenge. Over the past three decades, there have been several interventions to reduce such impact in the KZN program. The first was the release of all live sharks, including those species known to be responsible for fatal shark attacks. Measures to reduce catches of sharks associated with the winter influx of shoals of sardines, Sardinops sagax, have been increasingly successful. In addition, extensive removal of nets has resulted in a major reduction in effort. Collectively, these initiatives reduced mortalities of sharks by 64%. Baited lines, termed drumlines, were introduced at 18 beaches, where they replaced some of the nets. The former had a far lower by-catch of rays, turtles and cetaceans and significantly lower catches of certain shark species. Replacement of some nets with drumlines is planned for the remaining beaches. Only two attacks, both non-fatal, have occurred at protected beaches in KZN over the past three decades, indicating that the program has maintained its public safety mandate while it has succeeded in reducing its impact on the environment.

Adverse Events Reporting System as Experienced by Critical-Care Nurses in KwaZulu-Natal, South Africa

2018 ◽  
Vol 20 (1) ◽  
Author(s):  
Thusile Mabel Gqaleni ◽  
Busisiwe Rosemary Bhengu
Keyword(s):  
South Africa ◽  
Critical Care ◽  
Adverse Events ◽  
Patient Care ◽  
Family Involvement ◽  
Reporting System ◽  
Legal Framework ◽  
Critical Care Nurses ◽  
Kwazulu Natal ◽  
Life Threatening

Critically ill patients admitted to critical-care units (CCUs) might have life-threatening or potentially life-threatening problems. Adverse events (AEs) occur frequently in CCUs, resulting in compromised quality of patient care. This study explores the experiences of critical-care nurses (CCNs) in relation to how the reported AEs were analysed and handled in CCUs. The study was conducted in the CCUs of five purposively selected hospitals in KwaZulu-Natal, South Africa. A descriptive qualitative design was used to obtain data through in-depth interviews from a purposive sample of five unit managers working in the CCUs to provide a deeper meaning of their experiences. This study was a part of a bigger study using a mixed-methods approach. The recorded qualitative data were analysed using Tesch’s content analysis. The main categories of information that emerged during the data analysis were (i) the existence of an AE reporting system, (ii) the occurrence of AEs, (iii) the promotion of and barriers to AE reporting, and (iv) the handling of AEs. The findings demonstrated that there were major gaps that affected the maximum utilisation of the reporting system. In addition, even though the system existed in other institutions, it was not utilised at all, hence affecting quality patient care. The following are recommended: (1) a non-punitive and non-confrontational system should be promoted, and (2) an organisational culture should be encouraged where support structures are formed within institutions, which consist of a legal framework, patient and family involvement, effective AE feedback, and education and training of staff.

CHALLENGES TO BUILDING AUTHENTIC PARTNERSHIPS: LESSONS FROM BHAMBAYI, KWAZULU-NATAL, SOUTH AFRICA

2017 ◽  
Vol 26 (2) ◽  
pp. 124-140 ◽  
Author(s):  
Tanusha Raniga ◽  
Barbara Simpson ◽  
Ntokozo Mthembu
Keyword(s):  
South Africa ◽  
Social Services ◽  
Service Providers ◽  
Informal Settlement ◽  
Mutual Trust ◽  
Open Communication ◽  
Community Based ◽  
Individual Interviews ◽  
Kwazulu Natal ◽  
Qualitative Phase

In contemporary South Africa, partnerships between service providers in government, non-governmental organisations, the private sector and community based organisations have been identified as a means to strengthen communities and the sustainability of social services. However, the unequal power relations that exists between and within these organisations often leads to fragmentation, duplication, and lack of coordination of social services. Using Fowler’s (1998) conceptualisation of authentic partnerships, this qualitative phase of a larger study explored the challenges of building authentic partnerships in Bhambayi, a predominantly informal settlement in KwaZulu-Natal, South Africa. Individual interviews and a focus group held with nine service providers revealed that intraorganisational challenges, cross-boundary and inter-organisational relations as well as political influences were obstacles to the development of authentic partnerships. The article suggests that open communication, clarity of roles and mutual trust between service providers is vital.

Transforming the Rural Agricultural Landscape Through Groundwater Optimisation: Exploring A Chinese-South African Partnership

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Nirmala Dorasamy ◽  
Olayemi Bakre
Keyword(s):  
South Africa ◽  
South African ◽  
Agricultural Landscape ◽  
Agricultural Practices ◽  
Subsistence Farming ◽  
Water Shortages ◽  
Subsistence Farmers ◽  
Farming Communities ◽  
Standards Of Living ◽  
Kwazulu Natal

The majority of the South African rural populace is directly or indirectly engaged in agricultural practices to earn a livelihood. However, impediments such as climate change, water shortages, and inadequacy of institutional support have undermined these once thriving subsistence farming communities. Furthermore, poor leadership in hydrology, coupled with a lack of depth in skills at all government levels to facilitate the understanding of the importance of groundwater, has made it near impossible for subsistence farmers to benefit optimally from groundwater. The 2012 drought experienced in South Africa paralysed several subsistence farming communities in KwaZulu-Natal. To revamp subsistence farming and assist these farmers across South Africa, the Department of Water and Sanitation launched interventions, but despite the enormous resources expended, indicators (e.g. unsustainable farming practices, poor crop yield, pitiable living conditions, and poor standards of living) provide evidence that these interventions have not yielded the desired results. This paper seeks to suggest practicable interventions aimed at reducing the vulnerability of subsistence farmers in KwaZulu-Natal. The study pursued a qualitative approach in that it solicited the views of experts on groundwater and in related fields to gain an in-depth perspective. Some of the core challenges undermining the sustainability and growth of subsistence farming in the study area were found to be the inadequacy of experts on groundwater, water shortages, institutional deficiencies, lack of political will, and lack of coordination among stakeholders. Pragmatic recommendations are made to address these challenges, among other things to encourage a South African-Chinese partnership in the hydrology sector.

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