Spring sea-ice algae and ice-edge phytoplankton communities from the Laptev Sea polynya in 2012

• Published in: Permafrost and Periglacial Processes
• Main Authors: Polyakova, Yelena, Kryukova, Irina, Abramova, Ekaterina, Martynov, Fedor, Novikhin, Andrey, Kassens, Heidemarie, Hölemann, Jens
• Format: Conference Object
• Language: English
• Published: Zoological Institute of Russian Academy of Sciences 2014
• Subjects: Arctic; Asar; Laptev Sea; ice algae; laptev; lena river; Phytoplankton; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/27187/; https://oceanrep.geomar.de/id/eprint/27187/2/2014_Polyakova-etal_EMBS-49.pdf; https://doi.org/10.1002/ppp.450

Climate system of the Arctic is currently undergoing evident changes. The retreat of sea ice from the Arctic regions during the last 30 years has been receiving considerable attention. The wind-forced Laptev Sea polynya is a major area of sea-ice production in the Arctic, and it is one of the key elements of environmental system of the Laptev Sea. It is therefore essential to improve our knowledge of the Laptev Sea polynya system, as the crucial shelf area with high level of biological activity, and significant contributor to primary production. To investigate the influence of polynya on hydrological and hydrobiological properties of the Laptev Sea shelf waters, oceanographic station sites were generally confined to the location of the polynya area during Russian-German expedition TRANSDRIFT XX. To reveal temporal variability of these characteristics, the measurements were repeated several times at the same sites between March 19 and April 24 of 2012. The ENVISAR ASAR satellite imagery shows the evolution of the coastal polynya during this time. Therefore, our phytoplankton and sea-ice algal records allowed us to trace the development of biological processes in the polynya area during the early spring. Results of microalgae study revealed, that diatoms, represented mainly by sea-ice species are the predominant group of algae both in sea-ice communities and phytoplankton in the Laptev Sea during the time observation. The single cells of heterotrophic dinoflagellates were reported mainly in the phytoplankton communities. Detail investigations of microalgae allowed us to infer the distinctive regional features of algae assemblages and theirs development during the time observation: At the stations located in the southernmost part of the Laptev Sea polynya, in the vicinity of the Lena River Delta sea-ice bottom diatom communities characterized by the greatest algal abundances and biomass, which gradually increased during the observation period and reached the maximum at the end of this period. The lowest biomass ...