Community structure, distribution and trophic ecology of zooplankton on the Agulhas Bank with special reference to copepods

• Published in: South African journal of science Vol. 90; no. 3; pp. 154 - 165
• Main Authors: Verheye, H M, Hutchings, L, Huggett, JA, Carter, R A, Peterson, W T, Painting, SJ
• Format: Journal Article
• Language: English
• Published: 01.03.1994
• Subjects: Calanus agulhensis; Copepoda
• ISSN: 0038-2353

The mesozooplankton of the western Agulhas Bank is largely an extension of the west-coast upwelling community, whereas one copepod species, Calanus agulhensis, dominates the eastern Bank community, comprising up to 85% of the copepod biomass. Large populations of this copepod appear to be maintained on the eastern Bank, particularly during spring and early summer, in association with a subsurface ridge of upwelled water. This copepod appears to utilize efficiently the small cells which dominate te phytoplankton assemblage on the Agulhas Bank. Copepods may consume up to 50% of daily primary production. A low food-chain efficiency of < 3% suggests that a large portion of the primary production moves through microheterotrophs. A variety of commercially exploited fish and other planktivores, including invertebrates, compete for copepods as their primary food source. However, considerable research remains to be done to quantify the apportionment of copepods among their predators, and the effects of predation on copepod dynamics.