Population dynamics of the main copepod species in the Gulf of Gdańsk (the southern Baltic Sea): abundance, biomass and production rates

The aim of this study was to describe the production biomass and abundance dynamics of the major Baltic calanoid copepods (Acartia spp., Temora longicornis and Pseudocalanus sp.) in the Gulf of Gdansk (the southern Baltic Sea) during a three-year period from March 2010 to December 2012. The data were collected at six stations located in the western part of the gulf. Acartia spp. was the most abundant taxon throughout the study period. The observed differences in the weighted mean depth for the investigated species were >2 m between nauplii and adults of Acartia spp., >5 m between nauplii and adults of Temora longicornis and 3 m between nauplii and younger copepodites of Pseudocalanus sp. The highest values of the secondary production rates were determined for Acartia spp. - almost 17.55 mg C m^-2 d^-1 (summer 2011), while Temora longicornis reached 3.80 mg C m^-2 d^-1 in spring 2010 and Pseudocalanus sp. had the highest secondary production values in summer 2011 - about 1.28 mg C m^-2 d^-1.