ANNUAL REPORT 2011 - University of Namibia

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Figure 7: Distribution of Aequorea (left) and Chrysaora (right) along the central Namibian coast Figure 8: Distribution of Cetacea along Central Namibian coast. Yellow: Dusky Dolphins, Blue: Pilot whales, Red: Fin whales. Figure 9: Distribution of Fur Seals and seabirds along Central Namibian coast Conclusion The two species of jellyfish that were observed did not necessarily occur at the same places. We also found that seabirds and seals occurred together in many places. This might be linked to the distribution of their food, which is fish. Title: Nutrient cycle and the relevance of the Benguela Upwelling System for the biological pump Authors: Jeorgina Chiquequela (UNIversity of Namibia); Thulwaneng Mashifane (University of Cape Town) and Juvinaries Nyandoto (University of Namibia) 12
Introduction The Benguela is one of the four major upwelling ecosystems in the world and extends from South Angola, Namibia and South Africa. During upwelling water enriched with nutrients including Silicate, Phosphate and Nitrate reach the biologically productive surface of the ocean enhancing phytoplankton production. While the upwelling promotes primary production, the deeper waters with limited Oxygen exchange create hypoxic areas called oxygen minimum zones on the continental shelf. Phytoplankton blooms resulting from upwelling events provide the biological basis for transporting fixed carbon into the deep ocean (biological pump). This is achieved by carbon fixation (photosynthesis) and the processes of direct sedimentation of cells into the deep ocean as particulate organic carbon (POC). During the Maria S. Merian Cruise (Leg II/1b) nutrient cycle and the relevance of the Benguela Upwelling System for the biological pump was studied. Results Remineralisation of Phosphates takes place in the Oxygen minum zone ~ 350 m, during decomposition of phytoplankton cells (Figure 2 - 6). The decomposition cells transport carbon from the sea surface and bring it deep to the ocean floor through the biological pump. Figure 10: Dissolved oxygen and phosphate concentrations with depth for the stations investigated Figure 11: Dissolved oxygen and phosphate concentrations with the oxygen minimum zone (~ 350 m) in the Benguela upwelling system Conclusion Oxygen and phosphate are inversely proportional with depth. Poorly Dissolved Oxygen (DO) from the sea bottom utilize maximum oxygen in the oxygen minimum zone (~350–500 m), simultaneously releasing phosphate during decomposition of cells until sea floor. 13
Page 1 and 2: THE UNIVERSITY OF NAMIBIA SAM NUJOM
Page 3 and 4: 1. VISION To become a centre of exc
Page 5 and 6: 5. SANUMARC’S STRATEGIC MANAGEMEN
Page 7 and 8: Identical Contributing New N/A Tabl
Page 9 and 10: Figure 2: Members of SANUMARC Board
Page 11 and 12: Figure 5: Leg 2 Cruise Participants
Page 13: Figure 6: The distribution of the m
Page 17 and 18: Figure 12: Mean growth and specific
Page 19 and 20: Fresh weights(g) SGR (% d-1) a Figu
Page 21 and 22: Figure 17: Mushroom R & D and produ
Page 23 and 24: SPECIES NAME FAMILY LOCATION (Hochs
Page 25 and 26: The Centre was given approval to in
Page 27 and 28: Mrs Devota Kavishe, a PhD student w
Page 29 and 30: 14 NOTABLE VISITORS TO THE CENTRE

ANNUAL REPORT 2011 - University of Namibia

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