Fisheries - Enviro Dynamics Namibia

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F I S H E R I E S , M A M M A L S A N D S E A B I R D S S P E C I A L I S T S T U D Y As such direct impacts on non-target species are unlikely to occur. Rather it is the potential for the fishery to increase mortality on an already depleted target resource that is the main concern. Small pelagic species (sardine, horse mackerel, bearded gobies are an important link in marine food webs (Cury et al. 2000) and reductions in their abundance can have negative impacts on ecosystem structure and functioning (Crawford et al. 1985, Crawford et al. 1987, Boyer and Hampton 2001b). 3.5 DEMERSAL LONG-LINE FISHERY Final Report Namibian Marine Phosphate (Pty) Ltd. Page 28 Figure 14. Typical gear configuration of a pelagic purse seine vessel targeting small pelagic species Like the demersal trawl fishery the target species of this fishery is the Cape hakes, with a small non-targeted commercial by-catch that includes kingklip. The catch landed is predominantly prime quality (PQ) hake for export to Europe. The catch is packed unfrozen on ice – the fresh product is approximately 50% higher than that of trawled hake. Longline vessels fish in similar areas targeted by the hake-directed trawling fleet, in a broad area extending from the 300 m to 600 m contour along the full length of the Namibian coastline. Approximately 18 boats are currently (2011) operating primarily in three broad areas. Vessels based in Lüderitz work south of 26°S towards the South Africa border while those based in Walvis Bay operate between 23°S and 26°S and north of 23°S. Operations are ad hoc and intermittent, subject to market demand. A total hake TAC of 131,780 tonnes was set for 2011 but less than 10,000 tonnes of this is caught by long-line vessels. A demersal long-line vessel may deploy either a double or single line which is weighted along its length to keep it close to the seafloor (Figure 15). Steel anchors, of 40 to 60 kg are placed at the ends of each line. These anchor positions are marked with an array of floats. Lines are typically 20 – 30 nautical miles in length. Baited hooks are attached to the bottom line at regular intervals (1 to 1.5 m) by means of a snood. Gear is usually set at night at a speed of 5 – 9 knots. Once deployed the line is left to soak for up to eight hours before it is retrieved. A line hauler is used to retrieve gear (at a speed of approximately 1 knot) and can take six to ten hours to complete. During hauling operations the vessel’s manoeuvrability is severely restricted.
F I S H E R I E S , M A M M A L S A N D S E A B I R D S S P E C I A L I S T S T U D Y Figure 15. Typical configuration of demersal (bottom-set) hake longline gear used in Namibian waters Final Report Namibian Marine Phosphate (Pty) Ltd. Page 29
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Page 7 and 8: F I S H E R I E S , M A M M A L S A
Page 11 and 12: Tables and Figures F I S H E R I E
Page 13 and 14: 1 INTRODUCTION F I S H E R I E S ,
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Page 37 and 38: 4.2 TURTLES F I S H E R I E S , M A
Page 45 and 46: 5 LEGISLATION F I S H E R I E S , M
Page 47 and 48: Extent Duration Intensity/ Magnitud
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10 CONCLUSIONS F I S H E R I E S ,
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F I S H E R I E S , M A M M A L S A
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12 REFERENCES F I S H E R I E S , M
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Fisheries - Enviro Dynamics Namibia

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