According to the zooplankton observation in 2007-2008 at the different parts of the Kola Peninsula coastal areas, there are between 19-30 species and higher taxonomic groups of zooplankton. The abundance varied from 2500 – 38 500 individuals per m3 with a pronounced decrease in abundance eastward. Copepods were the dominating species in the samples with up to 90 % of total number of individuals. Boreal species as C. finmarchicus, T. longicornis, A. longiremis and C. hamatus were particular dominant compared to the cold waters species С. hyperboreus, M. longa, P. minutus and Microcalanus sp.
Data sampled from Dolgaya between May and September 2008 allows us to characterize the seasonal changes in composition, and quantitative parameters of the dominant groups. In May, copepod nauplii and younger copepodite stages of C. finmarchicus (I – III) was dominant and was found to comprise 90 % of the biomass. C. finmarchicus also dominated in June, but the species was found mainly as stage four. By July, neritic species of the copepods such as A. longiremis, C. hamatus, T. longicornis and the cladocerans E. nordmanni, P. leucartii became most abundant. Their total number reached up to 1600 individuals per m3 – composing 36 % of the community abundance. Predominant species were O. similis (21 %) and meroplanktonic forms (17 %). In August zooplankton community was represented mostly by benthic larvae of Cirripedians and Bivalves. They contributed for more than 80 % of total abundance. During September, the numbers of the meroplanktonic complex were reduced and copepods took back their otherwise dominant positions.
To summarize, during the period from May to September the species community was successive replaced by the three dominant components: C. finmarchicus; neritic copepods; and meroplanktonic forms.
Comparing abundance and life stages of Calanus species between years with different seawater temperature regimes.
