Improving the catch efficiency of the West Coast rock lobster, Jasus lalandii

2000 ◽  
Vol 51 (6) ◽  
pp. 613 ◽  
Author(s):  
D. Loewenthal ◽  
S. Mayfield ◽  
G. M. Branch
Keyword(s):  
Weight Loss ◽  
South African ◽  
West Coast ◽  
Capture Rate ◽  
Catch Rate ◽  
Rock Lobster ◽  
The South ◽  
The West ◽  
The Relationship

The South African commercial rock-lobster industry employs an average soak time of 22 h for traps. Experiments were undertaken to test (1) the rate of bait loss with soak time and the effect that protection of the bait has on bait loss, (2) the relationship between catch rate (numbers per trap) and soak time for traps with either protected or unprotected bait, and (3) the effect of two bait types (whole maasbanker and hake heads) on the catch of rock lobsters. There were substantial losses of unprotected bait within 6 h; substantially less weight loss was observed from protected bait even after a 48-h soak time. The numbers of rock lobsters caught in traps with unprotected bait were low relative to the capture rate with protected bait. The highest capture rate occurred after 6 h for unprotected bait and 6–12 h for protected bait. There was no significant effect of bait type (maasbanker v. hake heads) on the number or size of rock lobsters. To optimize catch efficiency, the commercial industry should use protected bait and soak times as short as 6–12 h.

The South African Fisheries: A Preliminary Survey of Historical Sources

2001 ◽  
pp. 167-180
Author(s):  
Lance van Sittert
Keyword(s):  
South African ◽  
West Coast ◽  
Marine Resources ◽  
Historical Records ◽  
Preliminary Survey ◽  
Rock Lobster ◽  
The South ◽  
Historical Sources ◽  
The West

Lance van Sittert explores the historical records concerning the exploitation of marine resources along the West Coast of Africa, using them to provide evidence of the commerical importance of the West Coast over the East or South. The date demonstrates a boom-bust cycle along the West Coast, pertaining to whales, snoek, guano, rock lobster, hake, and pilchard.

Using a GLMM to estimate the somatic growth rate trend for male South African west coast rock lobster, Jasus lalandii

2004 ◽  
Vol 70 (2-3) ◽  
pp. 339-349 ◽  
Author(s):  
A. Brandão ◽  
D.S. Butterworth ◽  
S.J. Johnston ◽  
J.P. Glazer
Keyword(s):  
Growth Rate ◽  
South African ◽  
West Coast ◽  
Somatic Growth ◽  
Rock Lobster ◽  
Somatic Growth Rate

scholarly journals Trains of African Easterly Waves and Their Relationship to Tropical Cyclone Genesis in the Eastern Atlantic

2017 ◽  
Vol 145 (2) ◽  
pp. 599-616 ◽  
Author(s):  
Abdou L. Dieng ◽  
Saidou M. Sall ◽  
Laurence Eymard ◽  
Marion Leduc-Leballeur ◽  
Alban Lazar
Keyword(s):  
West African ◽  
Dynamical Structure ◽  
African Easterly Waves ◽  
The South ◽  
The West ◽  
Easterly Waves ◽  
West African Coast ◽  
African Coast ◽  
Tropical Depressions ◽  
The Relationship

In this study, the relationship between trains of African easterly waves (AEWs) and downstream tropical cyclogenesis is studied. Based on 19 summer seasons (July–September from 1990 to 2008) of ERA-Interim reanalysis fields and brightness temperature from the Cloud User Archive, the signature of AEW troughs and embedded convection are tracked from the West African coast to the central Atlantic. The tracked systems are separated into four groups: (i) systems originating from the north zone of the midtropospheric African easterly jet (AEJ), (ii) those coming from the south part of AEJ, (iii) systems that are associated with a downstream trough located around 2000 km westward (termed DUO systems), and (iv) those that are not associated with such a close downstream trough (termed SOLO systems). By monitoring the embedded 700-hPa-filtered relative vorticity and 850-hPa wind convergence anomaly associated with these families along their trajectories, it is shown that the DUO generally have stronger dynamical structure and statistically have a longer lifetime than the SOLO ones. It is suggested that the differences between them may be due to the presence of the previous intense downstream trough in DUO cases, enhancing the low-level convergence behind them. Moreover, a study of the relationship between system trajectories and tropical depressions occurring between the West African coast and 40°W showed that 90% of tropical depressions are identifiable from the West African coast in tracked systems, mostly in the DUO cases originating from the south zone of the AEJ.

PASTURE SEED MIXTURE FOR HIGH RAINFALL DISTRICTS

1937 ◽  
pp. 71-78
Author(s):  
A. Stuart
Keyword(s):  
West Coast ◽  
The South ◽  
The West ◽  
High Rainfall ◽  
The North ◽  
Seed Mixture ◽  
Rainfall Map

In dealing with this subject it is essential to define the high rainfall districts, and on, perusing a rainfall map it was found, contrary to expectations, that the greater part of the North Island, as represented by the Auckland Province and Taranaki, has a rainfall of over 50 inches per annum. In the same category falls the West Coast of the South Island and all of Stewart Island.

scholarly journals Has the fishery contributed to a major shift in the distribution of South African sardine?

2008 ◽  
Vol 65 (9) ◽  
pp. 1676-1688 ◽  
Author(s):  
Janet C. Coetzee ◽  
Carl D. van der Lingen ◽  
Laurence Hutchings ◽  
Tracey P. Fairweather
Keyword(s):  
South African ◽  
West Coast ◽  
Management Practices ◽  
Fishing Effort ◽  
South Coast ◽  
The West ◽  
Natal Homing ◽  
Distinct Unit ◽  
Major Shift ◽  
Sardine Population

Abstract Coetzee, J. C., van der Lingen, C. D., Hutchings, L., and Fairweather, T. P. 2008. Has the fishery contributed to a major shift in the distribution of South African sardine? – ICES Journal of Marine Science, 65: 1676–1688. A major shift in the distribution of South African sardine (Sardinops sagax) has resulted in a significant spatial mismatch in fishing effort vs. fish abundance in recent years. The sardine fishery started on the west coast during the 1940s, and processing capacity there increased rapidly. This trend together with increases in annual landings continued up to the early 1960s, but then the fishery collapsed as a consequence of overfishing. The population then recovered steadily during the 1980s and 1990s, coincident with, but perhaps not entirely attributable to, the inception of conservative management practices, to support catches similar to pre-collapse levels. Since 2001, however, most of the sardine population has been situated on South Africa’s south coast, far from processing facilities. Fishing effort has increased concomitantly on that coast, particularly during the past three years, reflecting the continued decline in the abundance of sardine on the west coast. Three hypotheses explaining the change in the distribution of sardine have been proposed: (i) intensely localized (i.e. west coast) fishing pressure depleted that part (or functionally distinct unit) of the population; (ii) the shift was environmentally induced; and (iii) successful spawning and recruit survival on the south coast contributed disproportionately more towards the bulk of recruitment, and progeny spawned there now dominate the population and exhibit natal homing. The first of these hypotheses is evaluated, and management implications of the shift discussed.

Unraveling the South African Breast Cancer Story: The Relationship of Patients, Delay to Diagnosis, and Tumor Biology With Stage at Presentation in an Urban Setting

2019 ◽  
Vol 235 ◽  
pp. 181-189
Author(s):  
Sarah Rayne ◽  
Kathryn Schnippel ◽  
Surbhi Grover ◽  
Kirstin Fearnhead ◽  
Deirdre Kruger ◽  
...  
Keyword(s):  
Breast Cancer ◽  
South African ◽  
Tumor Biology ◽  
Urban Setting ◽  
The South ◽  
Relationship Of ◽  
The Relationship

Bass nurseries on the west coast of the U.K.

1986 ◽  
Vol 66 (2) ◽  
pp. 439-464 ◽  
Author(s):  
Donovan Kelley
Keyword(s):  
United Kingdom ◽  
West Coast ◽  
Dicentrarchus Labrax ◽  
The South ◽  
The West ◽  
The United Kingdom

INTRODUCTIONPresence of O-group bass, Dicentrarchus labrax (L.), has been recorded for a number of estuaries and tidal backwaters in the south of the United Kingdom, including the tidal Thames (Wheeler, 1979), the outer Thames at Southend (Murie, 1903), the Medway (Van den Broek, 1979), Langstone Harbour (Reay, 1973), the Dart (Dando & Demir, 1985), and the Tamar (Hartley, 1940). The author has found them, additionally, in Chichester Harbour and in the Cuckmere (Sussex), Teign and Tavy estuaries. Correspondents have reported them from the estuaries of the Blackwater (Cox), Crouch (Wiggins), Lynher (Gee) and Fal (Melhuish); also from the Fleet backwater in Dorset (Fear). It may be inferred that all estuaries and tidal backwaters on the south and south-east coasts of the U.K. constitute bass nurseries, in some degree.*

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