A population dynamics approach to the estimation of production of four calanoid copepods in Lindaspollene, western Norway

Abstract

Estimates were made of copepod production, based on estimates of recruitment, mortality. development times and individual weight data, and the methodological approach given earlier by Sonntag & Parslow is further developed. In addition to estimates of cohort production, the present approach includes estimation of daily production in depth and time. The estimation method is applied to abundance data of the copepodids of Pseudocalanus elongatus, Paracalanus parvus, Temora longicornis and Centropages hamatus obtained in LindAspollene in 1981. Production during June was estimated as 446, 252, 231 and 63 mg ash-free dry weight m-' respectively. Production of P. parvus and C. hamatus was primarily concentrated in the upper 5 m, while that of T. longicornis and P. elongatus was located below 5 m depth. The cohort P/B ratios were estimated in the range 2.5 to 6.8. The daily P/B ratios (including data for Calanus finmarchicus) were strongly dependent on the stage of development within the populations, but did not seem to differ much between species.