A Scottish Oyster Farmer in Namibia

Transcription

1 ASSG SHELLFISH CONFERENCE 2014 A Scottish Oyster Farmer in Namibia James West Whale Bay Oysters October 2014

2 History Oyster farming started in the 1980 s when the salt producers in Swakopmund introduced oysters to the first salt pan from the sea In 1996 new farms started in Walvis Bay and in Luderitz Walvis Bay used longlines and raft culture. Luderitz used intertidal racks and bags similar to above 2

3 Longlines and rafts 1.Longlines are usually 35 barrels long with 5 racks of oysters between each pair 2.One platform can hold around 250 racks 3

4 Cape Frio Terrace Bay Oyster growing locations Cape Cross Swakopmund Walvis Bay PRESENT HUBS OF COMMERCIAL MARICULTURE DEVELOPMENT Lüderitz Orangemund 4

5 B A C D E Namibian Ports Authority Farm Distribution Walvis Bay ALLOCATION Western Limit of Namport Water Area No. Tenant Area (ha) 1 Beira Aquaculture (Pty) Ltd 70,345 2 Namibia Aquaculture (Pty) Ltd 50,000 3 Pelican Point Shellfish 20,000 4 Namibia Oysters cc 29,203 5 Namibian Scallop Farming cc 19,011 6 Namib Aquaculture 19,169 7 Erongo Oysters 21,000 8a Seafresh Investments 21,000 8b Seafresh Investments 20,000 9 Global Polymer Industries (Pty) Ltd 28, Walvis Bay Mariculture Products (Pty) Ltd 34, Joe's Oysters 353, Praktika Afrika 35, Tetelestai Mariculture cc 37, Associate 56, Associate 52, Vacant 15, Uri Adventures 27, Associate 50, Associate 25,946 Pelican Point 20 Associate 35, Associate 45, Walvis Bay Mariculture Products (Pty) Ltd 3,650 NOTES Coloured Areas have been Allocated Grey Areas have been Applied for Blank Areas are vacant a 8b A B 2 3 D C Spoil Ground Please note that all the farms' co-ordinates are numbered in a clockwise direction, starting at the top lefthand corner as shown in diagram above. 11 PORT OF WALVIS BAY WALVIS BAY AQUA PARK WATER AREAS ALLOCATED FOR AQUACULTURE Port Engineer Southern Limit of Namport Water Area Date Drawn AWK Marais Checked AWK Marais WBH 602 Scale 1 : File HPM1/29 A 6602 Date 30 August 2006 Sht 1 of 2 Shts Grey coloured allocations in Walvis Bay are now unoccupied Plots are on average 45 hectares each in Walvis Bay and 10 hectares each in Luderitz 5

6 Farm Distribution Luderitz Plots are on average 45 hectares each in Walvis Bay and 10 hectares each in Luderitz 6

7 Upwelling Phytoplankton and Sulphur 7

8 Walvis Bay oysters

9 Fouling

10 Processes during an eruption intense continual upwelling at Luderitz phytoplankton bloom continually at a rate several times higher than in other coastal areas the plant cells die and decay, using oxygen en route anaerobic microbial processes produce H2S in the sediment build-up of gases is periodically released H 2 S fills the water column and pervades the atmosphere H 2 S oxidises to microgranules of sulphur at the water surface, discolouring it milky green

11 Sulphur bacteria mat 11

12 Gas in Sediment 12

13 Oxygen Profile Depth m Micromolar oxygen Sulphide

14 Mud Island 14

15 What Hydrogen Sulphide does Hydrogen sulphide toxic, comparable with cyanide inerferes with mitochondrial cytochrome oxidase enzymes thereby blocking cellular respiration sulphide competitively binds to haemoglobin A secondary impact combines with the available dissolved oxygen to create critically oxygen-limiting conditions during the episodic coastal events. 15

16 Mitigation High Lines 16

17 Oyster Poroduction Species No. Value N$ No. Value N$ No. Value N$ No. Value N$ No. Value N$ C. gigas 4, ,343,972 6,057,021 24,228,084 4,990,042 14,506,623 7,500,000 21,000,000 9,000,000 30,000,000 O. edilus Figures for last two years are estimates from farmers No figures are available for edilus but quantities are very small

18 Obstacles for Oyster Farming in Namibia Disruption of production by blooms and eruptions. Restriction of availability of capital No grant aid BEE requirements Remoteness from market. Cheap labour? Skills shortage and productivity

19 Opportunities Partnership / co-operation to ensure continuity of supply Room for expansion Excess of demand over supply New markets coming available Live vs Frozen, advantages and disadvantages Expansion Additional vessels, staff and infrastructure a leap of faith.