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 is expected at the dredging location. Both the displacement and mortality of this species will have a moderate impact on the whole ecosystem in the MLA only. Sole : (Figures 35 and 36) – Similar to monk, sole are a sedentary species preferring muddy substrate. They feed on polychaetes and other worms and fauna in the substrate. Their distribution is throughout the MLA and extending into the adjacent zone. Dredging operations will have a significant impact on sole abundance due to localise mortality. Some displacement of sole to adjacent areas away from the mining is expected. This localised impact will be long-term (at least 15 years) due to the removal of the preferred substrate of sole. Orange roughy : (Figures 37 and 38) – Orange roughy are only found in deeper waters and well outside of the MLA. No impact on the ecosystem is expected. Table 4. Impact assessment table of phosphate mining on the ecosystem Nature of the impact Extent Duration Intensity Probability Status (+ or -) Negative Significance (no mitigation) Mitigation Significance (with mitigation) Confidence level The impact of phosphate mining on the ecologically important demersal and pelagic fish species. The impact will result in the redistribution and/or displacement of hake, monk, horse mackerel, sole, orange roughy, bearded goby populations and small pelagics because of 1) actual mining activities due to dredging operations and vessel activities 2) habitat disturbances and the removal of substrate and 3) sediment plumes (turbidity) MLA - demersal and pelagic fish species will be displaced or redistributed from inside the MLA and possibly from the surrounding areas into Zone 1. Permanent (>20 yrs) - the impact will cease once the mining activity ends after 20 years (the period for which the mining licence is issued) however fish recovery is expected to occur sooner Moderate effects - only a small fraction (compared to the regional extent) of fish inhabit the MLA and fish populations will recovery or settle in areas after mining operations ceases however habitat destruction may cause a longer period of recovery particularly for monk and sole. Highly probable - fish (and in particular demersal fish) are expected to move away from the mining activity resulting in displacement of biomass Medium - the duration of the impact is permanent but recovery of fish populations in the area may occur in the long term. The intensity is minor to moderate and the extent is confined to the MLA and Zone 1 In terms of the ecosystem as a whole there are no particular mitigation measure that can be implemented. Not applicable (no mitigation alternatives) Low to medium - assumptions based on fish ecology is limited by the data available Final Report <strong>Namibia</strong>n Marine Phosphate (Pty) Ltd. Page 64
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 8.3 IMPACT 3: THE IMPACT OF PHOSPHATE MINING ON FISH RECRUITMENT We identify recruitment as the mechanism by which most fish species breed, spawn, migrate and ultimately become available for exploitation. The data used to this assessment are given in Table 5. The significance of the impact is summarised in Table 6. Table 5. Data (surveys) used in the assessment of the potential impacts of phosphate mining on fish recruitment Dataset Dates Hake length-frequency survey data 1995-2010 Final Report <strong>Namibia</strong>n Marine Phosphate (Pty) Ltd. Species (percentage of 100km buffer zone) Page 65 MLA (SP-1, SP-2 and SP-3) Horse mackerel juveniles (
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Final Report Namibian Marine Phosph
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Final Report Namibian Marine Phosph
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Tables and Figures F I S H E R I E
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1 INTRODUCTION F I S H E R I E S ,
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Fisheries - Enviro Dynamics Namibia

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