Composition, density and size-structure of the autotrophic plankton community in a shallow coastal zone at King George Island, West Antarctic Peninsula (WAP), during early summer 2010

• Published in: Brazilian Journal of Aquatic Science and Technology
• Main Authors: Barrera Alba, Jose Juan, Tenenbaum, Denise Rivera, Vanzan, Mariana, Tenório, Márcio Murilo Barboza
• Format: Article in Journal/Newspaper
• Language: English
• Published: UNIVALI 2016
• Subjects: Admiralty Bay; Antarctic; Antarctic Peninsula; King George Island; Antarc*
• Online Access: https://periodicos.univali.br/index.php/bjast/article/view/4731; https://doi.org/10.14210/bjast.v19n3.4731

The planktonic microorganism community of Admiralty Bay, Antarctic Peninsula is being monitored since 2002. This study describes composition, size-structure and biomass of the phytoplankton communities observed during early summer 2010/2011 in the area. Organisms were counted by microscopy and scored as belonging to three size classes: <10 µm, 10 - 80 µm and 80 - 400 µm. In terms of density, this phytoplankton community was dominated by cells < 10 µm (~106 - 107 cells L-1), confirming the increasing presence of small planktonic autotrophs in West Antarctic Peninsula waters. Organisms > 10 µm dominated in terms of biomass (> 50% of Chlorophyll a) with densities of up to 1.6 x 104 cells L-1, which is approximately 0.6 times higher than observed for early summer in recent years. Additionally, our results confirm a previously observed phenomenon whereby large-size phytoplankton (> 80 µm), especially pennate diatoms, are replaced by mid-size centric diatoms (10- 80 µm), such as Thalassiosira spp., and small dinoflagellates (e.g. Prorocentrum antarcticum) during warmer early summers.