Phytoplankton growth and zooplankton grazing in the southern Benguela current

The development and production of several phytoplankton communities and the consumption of these communities plankton were investigated in newly by herbivorous mesozooupwelled waters of the southern Benguela Current by means of an electronic counting and sizing technique (Coulter counter). A feasibility study was initiated to test the accuracy of the Coulter counter (Model TAII) in estimating phytoplankton size and biomass in fresh and preserved samples from the Benguela current. Counting phytoplankton using this method gave a higher degree of reproducibility than the inverted microscope method. Certain recommendations as to the counting procedures were made. The counting of preserved samples was shown to introduce artefacts, resulting in a 77 per cent reduction in particle volume after a year of preservation. Correlations of particle volume with chorophyll a, carbon and nitrogen were calculated, with highest correlations occurring between particle volume and chlorophyll a. Particle volume was shown to represent biomass as accurately as any of the other methods.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

1985

Author dc:creator

• Olivieri, Emilia T

Advisor dc:contributor.advisor

• Griffiths, Charles L

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/22590

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/22590