Algae sampling of the project CHALLENGE-2

The objective of this sampling is to know the biodiversity of the Antarctic algae communities (macroalgae and microalgae) and their temporal changes along the South Shetland Islands and the Antarctic Peninsula. Another objective of the sampling is to know the molecular biology of certain species of the red algae group and its nuclear patterns. For all this, it is necessary to carry out sampling both in the intertidal zone and in the sublitoral zone.
For this study, a total of 54 stations have been sampled. For intertidal communities, 25 x 25cm squares were taken with three replicates per community and a sample was obtained for each different species found throughout the season. For diatoms in the intertidal zone, three sediment falcon tubes were taken from the beach break area.
Samples for each species were also collected within the sublitoral zone and in addition to the target species for the molecular study.
Samples for each different species were also obtained in the sublitoral area and sampled in addition to the target species for molecular study. Diatoms were obtained by extracting sediment during diving or using multicore and gravity core, in which the first centimetres of sediment were obtained in a falcon tube. On the other hand, samples of epiphyte diatoms, found on benthic animals such as starfish or tunicates, were taken by scraping and later preserved in 70% alcohol.
A total of 218 samples of diatoms have been obtained and frozen at -20ºC for preservation. Those taken from sediment and animals have been kept in the refrigerator at 4ºC.
A total of 39 samples from squares have been taken. These samples have been classified by taxa at species level and weighed in wet weight.
Qualitative biodiversity samples have been 351. These have been stored in zip bags at -20ºC.
The samples for molecular studies have been 37 and preserved in three ways each sample; frozen, in Silica gel and in Carnoy (Solution of Ethanol and Glacial Acetic).
Analyses and calculations of these results will be carried out later in the Antarctic campaign.