Biogeographic study of the planktonic communities of the Prince Edward Islands (Southern Ocean)

• Published in: Journal of Plankton Research
• Main Authors: Froneman, P. W., Pakhomov, E. A.
• Format: Text
• Language: English
• Published: Oxford University Press 1998
• Subjects: ORIGINAL ARTICLES; Antarctic; Southern Ocean; Austral; Antarc*; antarcticus; Prince Edward Islands; Copepods
• Online Access: http://plankt.oxfordjournals.org/cgi/content/short/20/4/653; https://doi.org/10.1093/plankt/20.4.653

Microphytoplankton and zooplankton composition and distribution in the vicinity of the Prince Edward Islands and at the Sub-antarctic Front (SAF) were investigated in late austral summer (April/May) 1996. Samples were collected for analysis of chlorophyll a concentration (Chi a ), microphytoplankton and zooplankton abundance. Generally, the highest Chl a concentrations (up to 2.0 μg l−1) and zooplankton densities (up to 192 ind. m−3) were recorded at stations within the inter-island area while the lowest values (<0.4 μg l−1) were observed at stations upstream of the islands. High Chl a and zooplankton biomass values were also associated with the SAF. Microphytoplankton were dominated by chain-forming species of the genera Chaetoceros (mainly C.neglectus ), Fragilariopsis spp. and the large diatom Dactyliosolen antarcticus . The zooplankton assemblages were always dominated by mesozooplankton which at times contributed up to 98% of total zooplankton abundance and up to 95% of total biomass. Among mesozooplankton, copepods, mainly Clausocalanus brevipes and Metridia lucens numerically dominated. Among the macrozooplankton euphausiids, mainly Euphausia vallentini , E.longirostis and Stylocheiron maximum , and chaetognaths ( Sagitta gazellae ) accounted for the bulk of abundance and biomass. Cluster and ordination analysis did not identify any distinct biogeographic regions among either the microphytoplankton or zooplankton.