Incorporating technological interactions in a joint management procedure for South African sardine and anchovy

2016 ◽  
pp. 225-251
Keyword(s):  
South African ◽  
Joint Management ◽  
Management Procedure

scholarly journals Developing and refining a joint management procedure for the multispecies South African pelagic fishery

2004 ◽  
Vol 61 (8) ◽  
pp. 1432-1442 ◽  
Author(s):  
J.A.A. De Oliveira ◽  
D.S. Butterworth
Keyword(s):  
South African ◽  
Commercial Fisheries ◽  
Trade Off ◽  
Joint Management ◽  
Management Procedure ◽  
Large Fluctuations ◽  
Pelagic Fishery

Abstract Pilchard (sardine) and anchovy are the main targets of South Africa's pelagic fishery. This fishery is the country's second most valuable in monetary terms, and produces the highest annual yield in terms of landed mass (in recent years, a combined catch of the order of 400 000 t). It is the most dynamic of South Africa's main commercial fisheries, because the species targeted are relatively short-lived, often occur in mixed shoals, and experience large fluctuations in abundance. Mixed shoaling causes operational problems for the fishery, because of the inevitability of juvenile pilchard bycatch (of more value as adults for canning) in the anchovy-directed fishery. This operational interaction implies a trade-off between allowable catches for the two species, and hence necessitates that they are managed together. The development of a joint “management procedure” (sensu IWC) for the two species is described. This provides a framework for quantifying this trade-off, subject to the constraint that acceptable levels of risk of “collapse” are not exceeded for either resource. Important new features incorporated in a revision of the procedure implemented in 2002, which have made appreciably enhanced catches from the resources possible, are described.

scholarly journals Is the management procedure approach equipped to handle short-lived pelagic species with their boom and bust dynamics? The case of the South African fishery for sardine and anchovy

2011 ◽  
Vol 68 (10) ◽  
pp. 2075-2085 ◽  
Author(s):  
Carryn L. de Moor ◽  
Douglas S. Butterworth ◽  
José A. A. De Oliveira
Keyword(s):  
South African ◽  
Evaluation Process ◽  
Fish Population ◽  
Turn Of The Century ◽  
The South ◽  
Pelagic Species ◽  
Strategy Evaluation ◽  
Management Procedure ◽  
Boom And Bust ◽  
Boom Period

Abstract de Moor, C. L., Butterworth, D. S., and De Oliveira, J. A. A. 2011. Is the management procedure approach equipped to handle short-lived pelagic species with their boom and bust dynamics? The case of the South African fishery for sardine and anchovy. – ICES Journal of Marine Science, 68: 2075–2085. Worldwide, small shoaling pelagic fish manifest rapid and substantial natural changes in abundance. Is the application of a management procedure (MP), evaluated using simulation tests [i.e. a MP approach otherwise known as management strategy evaluation (MSE)], to recommend total allowable catches (TACs) with constraints desired by industry on the extent of interannual changes viable for such resources, particularly given the customarily lengthy MP evaluation process? This question is examined by considering the rapid boom and then bust situation that arose for the South African fishery for sardine (Sardinops sagax) and anchovy (Engraulis encrasicolus) across the turn of the century. Novel adaptations to the MP in place at the time of the boom allowed enhanced resource use during the boom period without compromising the risk of unintended depletion of the populations. Importantly a two-tier threshold system allowed the normal constraints on the maximum extent of interannual TAC reduction to be modified when TACs rose above the specified thresholds. The general protocol underlying the application of MPs for South African fisheries proved sufficiently flexible for the approach to continue to be applied, despite the unanticipated rapid fish population boom and then bust experienced.

Remaining challenges for bi-national agreements on shared water: The Umbeluzi case

Water Policy ◽  
2006 ◽  
Vol 8 (3) ◽  
pp. 231-253 ◽  
Author(s):  
Dinis Juizo ◽  
Rikard Lidén ◽  
Álvaro Carmo Vaz
Keyword(s):  
South African ◽  
Climatic Variability ◽  
Data Uncertainty ◽  
Actual System ◽  
International Convention ◽  
International Rivers ◽  
Joint Management ◽  
Effective Implementation ◽  
Form Part ◽  
Willingness To Cooperate

In Southern Africa, joint management of international waters is necessary for regional development and stability. The 1997 UN international convention on “watercourses for Non-navigational uses” and the 2000 revised SADC (South African Development Community) “Protocol on Shared Watercourses” form part of the platform towards minimising tension over utilisation of water resources in the region. Mozambique shares nine of 15 international rivers in SADC, hence its continued efforts towards reaching agreements with the riparian countries. However, effective implementation of these agreements remains a challenge. This study focuses on the implementation of future agreements in Umbeluzi River which has only two co-riparian sovereign states – Mozambique and Swaziland. In this case, it was found that several factors affect the effective implementation of the desired equitable sharing principle. The most prominent are hydrological data uncertainty, lack of adequate modelling tools and insufficient institutional capacity. Factors like large climatic variability in the region further worsen the situation. The overall implementation of agreements is also dependent on stakeholders' willingness to cooperate, which in turn is linked to their sense of fairness on decisions imposed by officials. However, correct regulation and enforcement can narrow the gap between technical ingenuity and the actual system behaviour.

Biology, fishery and management of sardines (Sardinops sagax) in southern African waters

1999 ◽  
Author(s):  
L. E. Beckley ◽  
C. D. van der Lingen
Keyword(s):  
South African ◽  
Southern Africa ◽  
Distribution Patterns ◽  
Total Allowable Catch ◽  
The North ◽  
Important Prey ◽  
Management Procedure ◽  
Age Related ◽  
By Catch ◽  
The 1960S

Sardines have been a major contributor to the pelagic fishery off southern Africa for several decades. The South African and Namibian stocks are separate, and seasonal hydrology, in conjunction with age-related behaviour, produces the observed size-distribution patterns. Sardines are relatively fast- growing and spawn repeatedly over the spring and summer months. Eggs and larvae are transported from the Agulhas Bank to the west coast by the north-flowing jet current at the shelf edge. Sardines are omnivorous, microphagist filter-feeders and are important prey for many piscivorous fishes, birds and mammals. There have been major fluctuations in sardine population biomass in southern Africa which have been associated with environment, regime shifts, recruitment and fishing. South African and Namibian sardine catches peaked in the 1960s, declining dramatically thereafter, and the pelagic fishing industry switched to anchovy. During the 1990s, sardine biomass increased but, although South African catches rose, the Namibian stock collapsed again. The annual South African total allowable catch is set through an operational management procedure that takes into account biomass estimates from comprehensive hydroacoustic surveys and the sardine by-catch in the anchovy fishery.

scholarly journals The application of a management procedure to regulate the directed and bycatch fishery of South African sardineSardinops sagax

1998 ◽  
Vol 19 (1) ◽  
pp. 449-469 ◽  
Author(s):  
J. A. A. de Oliveira ◽  
D. S. Butterworth ◽  
B. A. Roel ◽  
K. L. Cochrane ◽  
J. P. Brown
Keyword(s):  
South African ◽  
Management Procedure

The Three-dimensional structure of frozen-hydrated nudaurelia capensis β virus

1987 ◽  
Vol 45 ◽  
pp. 650-651
Author(s):  
N. H. Olson ◽  
T. S. Baker ◽  
Wu Bo Mu ◽  
J. E. Johnson ◽  
D. A. Hendry
Keyword(s):  
South African ◽  
Rna Virus ◽  
Carbon Film ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Electron Dose ◽  
Total Electron ◽  
Three Dimensional Structure ◽  
Negative Stain ◽  
Dimensional Reconstruction

Nudaurelia capensis β virus (NβV) is an RNA virus of the South African Pine Emperor moth, Nudaurelia cytherea capensis (Lepidoptera: Saturniidae). The NβV capsid is a T = 4 icosahedron that contains 60T = 240 subunits of the coat protein (Mr = 61,000). A three-dimensional reconstruction of the NβV capsid was previously computed from visions embedded in negative stain suspended over holes in a carbon film. We have re-examined the three-dimensional structure of NβV, using cryo-microscopy to examine the native, unstained structure of the virion and to provide a initial phasing model for high-resolution x-ray crystallographic studiesNβV was purified and prepared for cryo-microscopy as described. Micrographs were recorded ∼1 - 2 μm underfocus at a magnification of 49,000X with a total electron dose of about 1800 e-/nm2.

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