Simulated annual plankton production in the northeastern Pacific Coastal Upwelling Domain

• Published in: Journal of plankton research 1993, Vol.15 (2), p.161-183
• Main Authors: Robinson, Clifford L.K., Ware, Daniel M., Parsons, Timothy R.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; Synecology
• ISSN: 0142-7873; 1464-3774
• DOI: 10.1093/plankt/15.2.161

A microcomputer simulation model is presented that describes the generalized plankton production dynamics, in the surface mixed layer, of the Juan de Fuca Eddy located on the southwestern British Columbia continental shelf. The Juan de Fuca Eddy simulation model evaluates how the annual biomass production of diatoms, copepods and euphausiids is forced by plankton feeding interactions, seasonal variability in upwelling, water temperature and solar radiation, and generalized fish predation. The model estimates annual primary production of 345 g C m−2 year−1 and secondary production of 19.4 g C m−2 year−1 for copepods and 6 g C m−2 year−1 for euphausiids, during 1985–89; -90% of the annual plankton production was generated during the April-October upwelling season. Perturbations of 22 abiotic and biotic parameters, one at a time by ±10% of nominal values, indicated that oceanic variability (e.g. upwelling rate) most strongly affected primary production. Conversely, zooplankton production was most sensitive to variability in biological parameters describing zooplankton grazing potential and growth (e.g. gross growth efficiency). Simulated seasonal biomass patterns of diatoms, copepods and euphausiids were found to closely match empirical data. However, euphausiid biomass production in the Juan de Fuca Eddy alone was unable to meet the demands of estimated pelagic fish consumption. Local Eddy euphausiid populations had to be supplemented, from regional euphausiids. by a mechanism that is proposed to be linked to the seasonal pattern and intensity of positive Ekman transport (upwelling).