Location of Repository

Environmental variability in the Gulf of Guinea large marine ecosystem: physical features, forcing and fisheries

By Nicholas John Hardman-Mountford

Abstract

This thesis examines the forcing and behaviour of oceanographic physical features, relevant to recruitment in fish populations, in the Gulf of Guinea Large Marine Ecosystem, on seasonal and interannual time scales. Remotely sensed sea-surface temperature (SST) data covering the period 1981–1991 was used to identify and describe a number of oceanographic features, including the Senegalese Upwelling influence, the Ghana and Côte d’Ivoire coastal upwelling, river run-off, fronts and the previously unrecorded observation of shelf-break cooling along the coast of Liberia and Sierra Leone during the boreal winter. Interannual variability in SST was observed on an approximate three year scale and an extended warm phase was noted between 1987 and 1991. Principal components analysis (PCA) was used to further investigate the variance structure of these SST data and this technique was shown to be able to accurately define boundaries of the Gulf of Guinea system and its constituent subsystems. River discharge data from throughout the Gulf of Guinea was also investigated using PCA, confirming the hydroclimatic regions identified by Mahé and Olivry (1999). The boundaries between these regions correspond closely to those identified between subsystems in the SST data, suggesting a degree of coupling between oceanographic and meteorological variability in the Gulf of Guinea. To further investigate this coupling, local climate data and global/basin scale indices were compared qualitatively and statistically with remotely sensed and in situ SST data and indices of interannual variability in oceanographic features. A new basin scale index was proposed as a measure of zonal atmospheric variability in the subtropical North Atlantic (SNAZI) and this was shown to be the dominant mode of climate variability forcing SST in the Gulf of Guinea. The implications of these results for fisheries recruitment dynamics are discussed

Topics: QL, GC
OAI identifier: oai:wrap.warwick.ac.uk:1125

Suggested articles

Preview

Citations

  1. (1992). 3 Anticyclonic Slope Water Oceanic Eddies (Swoddies) in the Southern Bay of Biscay in
  2. (1987). A Comprehensive OceanAtmosphere Data Set.
  3. (1989). A difference in structure between ecosystems in strongly stratified waters and those that are rarely stratified.
  4. (1995). A High Resolution Global Sea Surface Temperature Climatology.
  5. (1981). A Linear Stratified Ocean Model of the Equatorial Undercurrent.
  6. (1986). A Model of the Seasonal Cycle in the Tropical Atlantic-Ocean.
  7. (1976). A numerical simulation of the onset of El Niño.
  8. (1997). A Pacific interdecadal climate oscillation with impacts on salmon production.
  9. (2000). A regime shift in the North Sea circa
  10. (1988). A review of the oceanography and fisheries resources in the coastal waters of Ghana.
  11. (1962). A review of the oceanography of the Gulf of Guinea.
  12. (1993). A Review of the Subsystems of the Canary Current and Gulf of Guinea Large Marine Ecosystems. IUCN Marine Programme.
  13. (1978). A simple model of upwelling in the Gulf of Guinea.
  14. (1958). An ecological survey of the West African marine benthos 11. Colonial Office Fishery Publication.
  15. (1994). An Empirical Orthogonal Function Analysis of Remotely Sensed Sea Surface Temperature Variability and its Relation to Interior Oceanic Processes off Baja California.
  16. (1995). An Estimate of Global Primary Production in the Ocean From Satellite Radiometer Data.
  17. (1977). and Collaborators
  18. (1980). Annual signal and interannual anomalies of sea surface temperature in the eastern equatorial Atlantic ocean.
  19. (1985). Anomalous warm events in eastern boundary current systems.
  20. (1987). Application of Principle Components Analysis to Change Detection. Photogrammetric Engineering and Remote Sensing
  21. (1999). Assessment of freshwater yields to the ocean along the intertropical Atlantic coast of Africa
  22. (1982). Atlantic herring: Stock discreteness and abundance.
  23. (1978). Atlas Hydrologique saisonnier de l'océan Atlantique intertropicale. Travaux et Documents de l'ORSTOM 82. ORSTOM,
  24. (1980). Atmosphere and tidal observations along the shelf of the Guinea Gulf.
  25. (1982). Atmosphere-Ocean Dynamics.
  26. (1986). Atmospheric Conditions in the Atlantic Sector During
  27. (1999). Atmospheric science - Does a globe-girdling disturbance jigger El Nino?
  28. (1998). Background and Focus. In: Large Marine Ecosystems of the Indian Ocean: Assessment, Sustainability
  29. (1983). Benthic-Pelagic Coupling and Export of Organic-Carbon from a Tropical Atlantic Continental-Shelf -
  30. (1976). Biovolumes et poids sec zooplanctoniques en relation avec le milieu pélagique au-dessus du plateau ivoirien.
  31. (1987). Cannabalism in South African anchovy: egg mortality and egg consumption rates.
  32. (1994). Changes in mean level, seasonal cycle and spectrum in long term coastal time series from various Eastern Ocean Systems.
  33. (1997). Characteristic length scales of spatial models in ecology via fluctuation analysis.
  34. (1976). Circulation and hydrographic structure over the Ghana continental shelf durinng the 1974 upwelling.
  35. (1973). Circulation dans le Golfe de Guinée. Etude de la région d'origine du sous-courant ivoirien. Cahiers ORSTOM,
  36. (1999). Climate and satellite indicators to forecast Rift Valley fever epidemics in Kenya.
  37. (1996). Climate Change
  38. (1999). Climate variability - The North Atlantic Oscillation.
  39. (2000). Climate variability and North Sea cod.
  40. (1998). Clupeoid population variability, the environment and satellite imagery in coastal upwelling systems.
  41. (1993). Coastal Conditions in West Africa - A Review.
  42. (1995). Coastal Sea Surface Temperature as Detected by Meteosat Satellite and Received at the University of Abidjan. In:
  43. (1970). Coastal upwelling in the Northwestern Gulf of Guinea.
  44. (1998). Cod: Perhaps if we all stood back a bit?
  45. (1983). Comparative climatology of selected environmental processes in relation to eastern boundary current pelagic fish reproduction.
  46. (1988). Coral Reefs of the World Volume 1: Atlantic and Eastern Pacific .
  47. (1980). Currents driven by a steady uniform wind stress on the shelf seas around the British Isles.
  48. (1997). Decadal predictability of North Atlantic sea surface temperature and climate.
  49. (1995). Decadal trends in the North Atlantic Oscillation: regional temperatures and precipitation.
  50. (1993). Description of the Different Large Marine Ecosystems of West Africa.
  51. (1969). Distribution of zooplankton and biological structure in the Tropical Atlantic.
  52. (1969). Dynamic response of the Indian Ocean to the onset of the southwest monsoon.
  53. (1991). Dynamical simulations of filament formation and evolution in the coastal transition zone.
  54. (1995). Dynamics and Use of Sardinella Resources from Upwelling off Ghana and Ivory Coast.
  55. (1996). Dynamics of Marine Ecosystems .
  56. (1976). Eastern tropical ocean response to changing wind systems: with application to El Niño.
  57. (1996). Ecological effects of the North Sea industrial fishing industry on the availability of human consumption species: a review. Univation at The Robert Gordon University.
  58. (1998). Ecological Geography of the Sea .
  59. (1987). Ecology of Tropical Oceans .
  60. (1999). Ecosystem analysis and the governance of natural resources. In: Advanced Ecological Theory.
  61. (1984). Effects of Remote Annual Forcing in the Eastern Tropical Atlantic Ocean.
  62. (1998). El Nino southern oscillation and North Atlantic oscillation control of climate in Puerto Rico.
  63. (1990). El Niño, La Niña and the Southern Oscillation. International Geophysics Series .
  64. (1978). Equatorial adjustment in the eastern Atlantic Ocean.
  65. (1986). Equatorial Atlantic-Ocean Temperature and Current Variations During
  66. (1984). Equatorial Beams.
  67. (1985). Equatorial Counter-Currents and Seasonal-Variations of HeatContent and Mean Sea-Level in the Eastern Tropical Atlantic.
  68. (1979). Equatorially trapped Rossby-gravity wave propagation in the Gulf of Guinea.
  69. (1978). Estuarine and Plume Fronts. In: Oceanic Fronts in Coastal Processes: Proceedings of a workshop held at the Marine Sciences Research
  70. (1972). Etude hydrologique du plateau continental ivoirien.
  71. (1970). Etude quantitative de l'upwelling sur le plateau continental ivoirien.
  72. (1971). Evaporation as the Upwelling Mechanism in Ghanaian Coastal Waters.
  73. (1973). Evaporation during upwelling in Ghanaian coastal waters.
  74. (1982). Evidence of remote forcing in the equatorial Atlantic ocean.
  75. (1975). Field criteria for survival of anchovy larvae: the relation between inshore chlorophyll maximum layers and succesful first feeding.
  76. (1995). Fish and Fisheries of Three Coastal Lagoons
  77. (1989). Fisheries production biomes in the northeast Pacific Ocean.
  78. (1998). Fishstat Plus, Food and Agriculture Organization of the United Nations.
  79. (1986). Fleuves et rivieres du Cameroun. These d'Etat . ORSTOM,
  80. (1914). Fluctuations in the great fisheries of northern Europe viewed in the light of biological research.
  81. (1987). Fluctuations of a Fortnightly Abundance Index of the Ivorian Coastal Pelagic Species and Associated Environmental Conditions.
  82. (1979). Forced baroclinic ocean motions, III: The linear equatorial basin case.
  83. (1997). General Bathymetric Chart of the Oceans (GEBCO) '97 Digital Atlas, British Oceanographic Data Centre/International Oceanographic Commission/International Hydrographic Organisation/Natural Environment Research Council,
  84. (1997). German program for ocean remote sensing. In: Space Remote Sensing of Sub-tropical Oceans.
  85. (1998). Global scale decadal climate variability.
  86. (1986). Global water masses: Summary and review.
  87. (1999). Gravity field determination with GOCE and GRACE.
  88. (1992). Growth, survival and recruitment in large marine ecosystems. In: Large Marine Ecosystems - Patterns, Processes
  89. (1978). Guinea Current Upwelling.
  90. (1996). Gulf of Guinea Large Marine Ecosystem Project. Brochure. The Regional Coordination Centre, Abidjan, Côte d'Ivoire.
  91. (1998). Gulf Stream shifts following ENSO events.
  92. (1992). Importance écologique de la petite saison d'upwelling ivoiro-ghanéenne et changements dans la pêcherie de Sardinella aurita.
  93. (1999). Initial analysis of ocean color data from the ocean color and temperature scanner.
  94. (1985). Interannual and seasonal variability of the tropical Atlantic Ocean depicted by sixteen years of sea-surface temperature and wind stress. In: Coupled Ocean-Atmosphere Models.
  95. (1994). Interannual scales of variation of pigment concentrations from coastal zone colour scanner data in the Benguela Upwelling system and the Subtropical Convergence zone south of Africa.
  96. (1998). Interdecadal modulation of ENSO teleconnections.
  97. (1999). Interdecadal variations in Japanese sardine and ocean/climate.
  98. (1978). Introduction and Historical Perspective. In: Oceanic Fronts in Coastal Processes: Proceedings of a workshop held at the Marine Sciences Research
  99. (1985). Introduction to 'Satellite Oceanic Remote Sensing'.
  100. (1987). Kinematics of the upwelling front off southern Africa.
  101. (1991). La variabilité des apports fluviaux au Golfe de Guinée utilisée comme indice climatiques. In: Pêcheries Ouest-africaines: variabilité, instabilité et
  102. (1992). Large Marine Ecosystems: Patterns, Processes and Yields. American Association for the Advancement of Science,
  103. (1993). Les écoulements fluviaux sur la façade atlantique de l'Afrique. Étude des éléments du bilan hydrique et variabilité interannuelle, analyse de situations hydroclimatiques moyennes et extrêmes. PhD Thesis. l'université Paris XI Orsay,
  104. (1970). Les saisons marines devant Abidjan. Documents Scientifique Centre de Recherche Océanographique Abidjan
  105. (1993). Long sequence time series evaluation using standardized principal components. Photogrammetric Engineering and Remote Sensing
  106. (1975). Marine Ecology and Fisheries .
  107. (1997). Marine Fisheries of Nigeria: Recent investigations, resource evaluation, state of exploitaion and management strategies. Prepared for the CECAF (Commitee for Eastern Central Atlantic Fisheries) Working Party on Resources Evaluation,
  108. (1986). Marine Fishery Resources of Nigeria: A review of exploited fish stocks. 86/40 (En).
  109. (1979). Marine Microplankton from Sierra Leone (West Africa).
  110. (1997). Microwave remote sensing of coastal zone salinity.
  111. (1978). Mixing and stabilization of phytoplankton distributions on the northwest European continental shelf. In:
  112. (1996). Modelling Marine Processes .
  113. (1977). Modelling of the tropical oceanic circulation.
  114. (1997). MOS a spaceborne imaging spectrometer for ocean remote sensing. Backscatter,
  115. (1997). NAG Fortran Library. The Numerical Algorithms Group (NAG) Ltd.,
  116. (1991). Nanisme et sedentarité chez certaines espèces de poissons pélagique: deux aspects d'un même réponse à des conditions défavorables. In: Pêcheries Ouestafricaines: variabilité, instabilité et
  117. (1999). NCAR's Data Support Section.
  118. (1999). Neural network for emulation of an inverse model -operational derivation of Case II properties from MERIS data.
  119. (1983). Note on swarms of Thaliacea in the Gulf of Guinea.
  120. (1991). Nutrient provinces in the sea: Concentration ratios, reaction rate ratios and ideal covariation.
  121. (1977). Observational and numerical evidence for wind-forced coastal trapped long waves.
  122. (1988). Observations of vortex dipoles on the Benguela upwelling front.
  123. (1988). Ocean basin ecosystems. In: Concepts of Ecosystem Ecology.
  124. (1989). Ocean Circulation. Oceanography Series 3.
  125. (1999). Oceanic forcing of the wintertime North Atlantic Oscillation and European climate.
  126. (1978). Oceanic Fronts in Coastal Processes:
  127. (1980). On coastal waves trapped at low latitudes.
  128. (1986). On the Baroclinic Response of the Zonal Pressure-Gradient in the Equatorial Atlantic-Ocean.
  129. (1979). On the generation of the seasonal coastal upwelling in the Gulf of Guinea.
  130. (1989). Optimal Environmental Window and Pelagic Fish Recruitment Success in Upwelling Areas.
  131. (1996). Patterns in the Ocean: Ocean Processes and Marine Population Dynamics . California Sea Grant College System,
  132. (1982). Persistence of sub-Saharan drought.
  133. (1978). Physical Aspects and Biological Consequences of Ghanaian Coastal Upwelling. In: Upwelling Ecosystems.
  134. (1968). Planetary gravity waves in an equatorial ocean. PhD Thesis.
  135. (1995). Primary production required to sustain global fisheries.
  136. (1978). Prograde and Retrograde Fronts. In: Oceanic Fronts in Coastal Processes:
  137. (1983). Propagation of the seasonal upwelling in the eastern equatorial Atlantic.
  138. Rébert (1973b). Les courants marins dans le Golfe Ivoirien. Cahiers ORSTOM,
  139. (1987). Remote Sensing and Image Interpretation .
  140. (1983). Remote-Sensing of Phytoplankton in the Sea - SurfaceLayer Chlorophyll As an Estimate of Water-Column Chlorophyll and Primary Production.
  141. (1977). Répartition et abondonce évaluées par échointégration des poissons du plateau continental ivoiro-ghanéen en relation avec les upwellings locaux.
  142. (1994). Report of the Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records,
  143. (1968). Report on the Guinean Trawling Survey 99. Organisation of African Unity Scientific and Technical Research Commission.
  144. (1981). Response of Equatorial Oceans to Periodic Forcing.
  145. (1982). Response of the western Equatorial Atlantic Ocean to an annual wind cycle.
  146. (1996). Review of the Canary Current and Guinea Current Large Marine Ecosystems.
  147. (1996). SANTIS - a tool for Signal ANalysis and TIme Series processing. Version 1.1: User Manual.
  148. (1992). Sardine and anchovy regime fluctuations of abundance in four regions of the worlds oceans: A workshop report.
  149. (1985). Satellite observations of surface temperature and near surface chlorophyll in the southern Benguela region.
  150. (1995). Sea surface temperature retrieval in tropical area with Meteosat: the case of the Senegalese coastal upwelling.
  151. (1980). Seasonal heat budget in the equatorial Atlantic ocean.
  152. (1987). Seasonal heat content of the eastern tropical Atlantic.
  153. (1983). Seasonal Variability From a Model of the Tropical Atlantic-Ocean.
  154. (1983). Seasonal variations of the subsurface thermal structure in the Gulf of Guinea.
  155. (1999). Signature of recent climate change in frequencies of natural atmospheric circulation regimes.
  156. (1984). Slope currents and 'JEBAR'.
  157. (1984). Some Applications of Remote-Sensing to Studies in the Bay of Biscay, Celtic Sea and English-Channel. In: Remote Sensing of Shelf Sea Hydrodynamics.
  158. (1999). Spatial and temporal variations in benthic fauna and communities of the tropical Atlantic coast of Africa. In: The Gulf of Guinea Large Marine Ecosystem: Environmental forcing and sustainable development of marine resources.
  159. (1998). Spatial dynamics of the upwelling off Côte d'Ivoire. In: Global versus local changes in upwelling systems.
  160. (1969). Species assemblages in tropical demersal fisheries.
  161. (1977). Stochastic climate models, Part II: Application to sea-surface temperature anomalies and thermocline variability.
  162. (1997). Sustainable Fisheries Management in Mauritania. PhD Thesis.
  163. (1998). Temporal and spatial patterning of sea surface temperature in the northern Benguela upwelling system; possible environmental indicators of clupeoid production.
  164. (1989). The Analysis of Time Series: An Introduction .
  165. (1984). The association between the North Atlantic Oscillation and the Southern Oscillation in the Northern Hemisphere.
  166. (1996). The Atlantic Meridional Transect: An oceanographic research programme to investigate physical, chemical, biological & optical variables of the Atlantic Ocean.
  167. (2000). The Atlantic Meridional Transect: Overview and synthesis of data.
  168. (1999). The atmospheric correction of water colour and the quantitative retrieval of suspended particulate matter in Case II waters: application to MERIS.
  169. (1999). The Atmospheric Response over the North Atlantic to Decadal Changes in Sea Surface Temperature.
  170. (2000). The ATSR Project.
  171. (1989). The biological pump: Profiles of plankton production and consumption in the open ocean.
  172. (1982). The biology of clupeoid fishes.
  173. (1992). The Black-Sea in Crisis - a Need For Concerted International Action.
  174. (1993). The California Current, Benguela Current and Southwestern Atlantic Shelf Ecosystems: A Comparative Approach to Identifying Factors Regulating Biomass Yields. In:
  175. (1964). The coastal oceanography of Western Nigeria.
  176. (1991). The Coastal Transition Zone Program.
  177. (1991). The Comparative Ecology of 6 Marine Ecosystems.
  178. (1995). The Côte d'Ivoire and Ghana Coastal Upwellings: Dynamics and Changes. In:
  179. (1995). The Droguing of Meddy Pinball and Seeding With Alace Floats.
  180. (1995). The ECMWF contribution to the characterisation, interpretation, calibration and validation of ERS-1 scatterometer backscatter measurements and winds, and their use in numerical weather prediction models. ESA Contract Report.
  181. (2000). The elements of climate variability in the tropical Atlantic region.
  182. (1999). The ESA Medium Resolution Imaging Spectrometer MERIS - a review of the instrument and its mission.
  183. (1980). The generation of equatorial currents.
  184. (1982). The Growth of Biological Thought .
  185. (2000). The Gulf of Guinea Large Marine Ecosystem. In: Seas at the Millenium: An Environmental Evaluation.
  186. (1998). The impacts of environmental forcing on the dynamics of demersal fishery reources of Ghana. PhD Thesis.
  187. (1993). The Large Marine Ecosystem of Shelf Areas in the Gulf of Guinea: Long-Term Variability Induced by Climatic Changes. In:
  188. (1970). The NCOR report on the mechanism of the upwelling of Ghana's coastal waters.
  189. (1981). The Oceanic Response to Cross-Equatorial Winds (With Application to Coastal Upwelling in Low Latitudes).
  190. (1997). The past and the future of El Nino.
  191. (1989). The physical basis for recruitment variability in fish populations.
  192. (1986). The Physical Nature and Stucture of Oceanic Fronts.
  193. (1995). The Physical Processes of Coastal Ocean Upwelling Systems. In: Report of the Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records,
  194. (1992). The potential effects of cannabilism and intraguild predation on anchovy recruitment and clupeoid fluctuations.
  195. (1997). The recent increase in North Atlantic wave heights.
  196. (1979). The response of an equatorial ocean to simple wind stress patterns: II. Numerical results.
  197. (1981). The Response of Equatorial Oceans to a Relaxation of the Trade Winds.
  198. (1979). The seasonal cycle of the phytoplankton in the coastal waters of Ghana.
  199. (1978). The Seasonal Upwelling in the Gulf of Guinea due to Remote Forcing.
  200. (1998). The storm in the machine.
  201. (1997). The Surface Dynamics of the Northern Benguela Upwelling System and its Relationship to Patterns of Clupeoid Production. PhD Thesis.
  202. (1981). The termination of the equatorial undercurrent in the eastern Pacific. PhD Thesis.
  203. (1988). The watch of ITCZ migrations over the tropical Atlantic Ocean as an indicator in drought forecast over the Sahelian area.
  204. (1986). Thermal structure along 4oW in the Gulf of Guinea during 1983-1984.
  205. (1992). Time Series Map Analysis using Standardized Principle Components.
  206. (1990). Time Series: A Biostatistical Introduction.
  207. (1996). Towards a science of recruitment in fish populations.
  208. (1997). Trimming problems and remedies in COADS.
  209. (1993). Trophic Models of Aquatic Ecosystems.
  210. (1986). Unusual Conditions in the Tropical Atlantic-Ocean in
  211. (1979). Upwelling in the Gulf of Guinea.
  212. (1981). Upwelling in the Gulf of Guinea. Results of a mathematical model. In: Ecohydrodynamics.
  213. (1994). Upwelling in the Ocean: Modern Processes and Ancient Records. In: Report of the Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records,
  214. (1973). Upwelling studies based on surface observations. Coastal Upwelling Experiment Workshop Abstracts,
  215. (1983). Variability of coastal zones in low latitudes (with application to the Somali Current, the Gulf of Guinea and the El Nino Current). In: Hydrodynamics of the Equatorial Ocean.
  216. (1999). Variability of Fram Strait ice flux and North Atlantic Oscillation.
  217. (1995). Variations des précipitations et des écoulements en Afrique de l'Ouest et centrale de 1951 à
  218. (1991). Variations locale de l'upwelling, répartition et abondance des sardinelles en Côte d'Ivoire. In: Variabilité, instabilité et changement dans les pêcheries ouest africaines.
  219. (1991). Variations spatiales et temporelles de la résurgence ivoiro-ghanéenne. In: Variabilité, instabilité et changement dans les pêcheries ouest africaines.
  220. (1963). Varieties of oceanographic experience.
  221. (1983). Vertical Distribution of Larvae of Mackerel (Scomber scombrus) and microplankton, with some conclusions on feeding conditions and survey methods.
  222. (1992). Weather Cycles: Real or Imaginary? .
  223. (1983). Why do some pelagic fishes have wide fluctuations in their numbers? Biological basis of fluctuation from the viewpoint of evolutionary ecology.
  224. (1974). Wind induced upwelling, coastal currents and sea-level changes.
  225. (1999). Worldwide large-scale fluctuations of sardine and anchovy populations.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.