Occurrence of metazoans, and gut pigments and fatty acid composition of Acartia bifilosa in ice and under-ice water samples from Santala Bay

• Main Authors: Werner, Iris, Auel, Holger
• Format: Dataset
• Language: English
• Published: PANGAEA 2004
• Subjects: Finland; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Santala; SEAICEC; Sea ice corer; SPP1158; Antarctic; Arctic; Antarc*; Phytoplankton; Sea ice; Rotifer
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.855495; https://doi.org/10.1594/PANGAEA.855495

A field study was conducted in Santala Bay with weekly samplings during February and March 2000. Ice thickness was 20-28 cm, snow cover 0-1 cm. The under‐ice water column was stratified with a cold (-0.3 - 0.2°C) and less saline (S = 2.1-4.9) interface layer. Concentrations of particulate organic carbon (0.5–5.8 mg POC/l) and algal pigments (0.3-18.2 µg chlorophyll a/l) were higher in the ice than in the water (0.2-0.5 mg POC/l, 1.6–7.1 µg chlorophyll a/l) and peaked mostly in the bottom part of the ice. The thin ice and almost lacking snow cover had favoured an early ice‐algal and phytoplankton bloom. The diversity of metazoans was low, with six species in the ice and eight species in the under‐ice water. The rotifer Synchaeta cf. littoralis dominated both in ice and water, with maximum abundances of 230 individuals/l in the bottom part of the ice. Rotifer eggs were also observed in the ice. Baltic sea ice seems to be a suitable habitat for rotifers. Nauplii and copepodids of the calanoid Acartia longiremis in the under‐ice water showed some herbivorous feeding (<0.1-0.23 ng gut pigment/individual), but analysis of fatty acids, fatty alcohols and biomarker ratios indicated a more omnivorous/carnivorous diet. Despite low temperatures, this copepod showed growth and development below the ice, doubling in numbers (mainly CI, CII) from 118 to 230 individuals m during the third week of March.