Sea-ice eukaryotes of the Gulf of Finland, Baltic Sea, and evidence for herbivory on weakly shade-adapted ice algae

• Published in: European Journal of Protistology
• Main Authors: Majaneva, Markus, Blomster, Jaanika, Mueller, Susann, Autio, Riitta, Majaneva, Sanna, Hyytiainen, Kirsi, Nagai, Satoshi, Rintala, Janne-Markus
• Other Authors: Environmental Sciences, Tvärminne Zoological Station, Jaanika Blomster / Principal Investigator, Life Science Education, Marine Ecosystems Research Group, Teachers' Academy
• Format: Article in Journal/Newspaper
• Language: English
• Published: ELSEVIER GMBH, URBAN & FISCHER VERLAG 2020
• Subjects: 18S rRNA gene; Accessory pigments; Herbivory; Photoacclimation; Sea ice; RIBOSOMAL-RNA GENE; CHLOROPHYLL-A DEGRADATION; PROTISTAN COMMUNITY; MCMURDO SOUND; ARCTIC-OCEAN; PHYTOPLANKTON; WATER; DINOFLAGELLATE; DIVERSITY; NUTRIENT; 1183 Plant biology; microbiology; virology; Arctic; Arctic Ocean; McMurdo Sound; ice algae; Phytoplankton
• Online Access: http://hdl.handle.net/10138/309517

To determine community composition and physiological status of early spring sea-ice organisms, we collected sea-ice, slush and under-ice water samples from the Baltic Sea. We combined light microscopy, HPLC pigment analysis and pyrosequencing, and related the biomass and physiological status of sea-ice algae with the protistan community composition in a new way in the area. In terms of biomass, centric diatoms including a distinct Melosira arctica bloom in the upper intermediate section of the fast ice, dinoflagellates, euglenoids and the cyanobacterium Aphanizomenon sp. predominated in the sea-ice sections and unidentified flagellates in the slush. Based on pigment analyses, the ice-algal communities showed no adjusted photosynthetic pigment pools throughout the sea ice, and the bottom-ice communities were not shade-adapted. The sea ice included more characteristic phototrophic taxa (49%) than did slush (18%) and under-ice water (37%). Cercozoans and ciliates were the richest taxon groups, and the differences among the communities arose mainly from the various phagotrophic protistan taxa inhabiting the communities. The presence of pheophytin a coincided with an elevated ciliate biomass and read abundance in the drift ice and with a high Eurytemora affinis read abundance in the pack ice, indicating that ciliates and Eurytemora affinis were grazing on algae. (C) 2016 Elsevier GmbH. All rights reserved. Peer reviewed