Structure, diversity and habitat characterization of Copepods from the Cape Ghir upwelling, Morocco

Abstract

The zooplankton, of the Cape Ghir filament area in Morocco (31°N), was sampled during five oceanographic cruises conducted between 2008 and 2009. Physical and chemical parameters were measured. In total, 11 stations were sampled on two radial perpendiculars: one latitudinal (31°N) with 7 stations coast-large and the other longitudinal (10°09' W) with 5 stations North-South. The intersection between the two radial corresponds to station 4. Copepods constitute the largest fraction of zooplankton community and represented by 86 species. The temporal variability in the copepod community structure showed that the dominant species listed may change their dominance during the study period. Their composition could be analyzed for changes in community structure associated with oceanographic variation with statistical analysis. The relation between the distribution of copepods species and the environment parameters, shows that some species (Paracalanus parvus, Oncaea venusta, Acartia clausi, Oithona nana and Euterpina acutifrons) are mainly correlated with chlorophyll 'a' and nutrients. However, other species (Oithona plumifera, Oithona similis and Clausocalanus arcuicornis) are correlated with temperature and salinity. Eight copepods species “Acartia clausi, Calanus helgolandicus, Neocalanus gracilis, Oithona nana, Oithona similis, Oithona plumifera, Oncaea venusta and Paracalanus parvus” are characterized by their high frequency and their dominance in all periods and were analyzed specially with their relation to the hydrological parameters to determinate their Environmental Preference Habitat. The global quotients were calculated in relationship with each of the hydrological and productive parameters; considered as the most influencing on the distribution of these species. Moreover, the temperature and the chlorophyll 'a' seem to be the most important factors in the determination of the copepod’s habitats in Cape Ghir area.