L4 Calanus egg production time-series

The long series of high-frequency observations of Calanus helgolandicus reproduction is unique; no other such data-set exists. This fact, combined with the extensive information on the food environment (particulates, phytoplankton species) and experimental studies on the diet and reproduction of Calanus (e.g. Pond et al., 1996; Irigoien et al., 1999; Meyer-Harms, et., 1999) provides an important opportunity to advance zooplankton seasonal succession modelling, and investigations of inter-annual variability at higher trophic levels.

Female Calanus helgolandicus, and occasionally other species, were captured during mid-morning and incubations were initiated at mid-day. Five replicates of 5 healthy females were randomly picked from the net samples and incubated for 24 h in 2 l glass beakers. Each beaker contained a plexiglass egg production tube (mesh 500 µm) and was filled with 0.2 µm filtered seawater at ambient sea temperature.

Users are encouraged to get in touch with the originators for advice on the consistency of particular data-sets. The data can be downloaded from BODC or the Pangaea website as files for each year by searching for "L4 egg production"