Plankton structure a in shallow coastal zone at Admiralty Bay, King George Island West ­Antarctic Peninsula (WAP): composition of ­phytoplankton and influence of benthic ­diatoms

Abstract

The phytoplankton composition and biomass are being monitored in Admiralty Bay, Antarctic Peninsula since 2002 to detect possible interannual changes on a long-term monitoring perspective. In this report, we present the results of the 2009/2010 monitoring program regarding the phytoplankton composition during the PROANTAR XVIII operation. The community was dominated by both planktonic and benthic diatoms. A total of 140 species were found, many of them awaiting further morphological studies to determine their specific identity. A preliminary assessment of habitat preferences was made, showing that the diatoms in the Admiralty Bay came from distinct substrates like ice, rocks, sediments, plankton and macroalgae. These results indicate that benthic microalgae, particularly diatoms, play an important role in primary productivity of the pelagic community in inshore waters. The next steps will be to refine identification to analyse the whole water samples and to relate the results with the environmental and hydrographical features in Admiralty Bay.

Abiotic Changes Driving Microphytoplankton Functional Diversity in Admiralty Bay, King George Island (Antarctica)

“…and Prorocentrum spp.) (Kopczyńska, 2008;Tenenbaum et al, 2010;Lange et al, 2014Lange et al, , 2018 this study) indicates a change in phytoplankton species composition (Lange et al, 2018). This supports the findings of other studies in AB (Sector 1) and King George Island (sector 2), that highlighted shifts in biota due to environmental changes (increase in solar radiation and temperature, thus increasing the sea ice melting) (Kopczyńska, 2008;Schloss et al, 2012;Campos et al, 2013;Mendes et al, 2013Mendes et al, , 2018Saba et al, 2014;Schofield et al, 2017).…”

“…Salinity exhibited little variation, with values higher than 34.0, except at the end of summer 2014-2015 when average values were lower, as observed in the literature both for AB (sector 1) and King George Island (sector 2) (Lange et al, 2018). Lange et al (2014) observed higher salinities during the beginning than at the end of the summer, while Tenenbaum et al (2010) reported reduced salinity for neritic regions, possibly due to the presence of glaciers in the region. In this context, Mendes et al (2018) found lower values for salinity (mean 33.68) in areas near ice-covered regions and higher values (mean 34.14) in regions with little or no influence of ice cover seasonality for sector 7 (Weddel-Scotia Confluence Zone), thus correlating low salinity with water column stability.…”

“…The decrease in cell size of microphytoplanktonic organisms in relation to hydrological conditions is noteworthy (e.g., Tenenbaum et al, 2010;Barrera-Alba et al, 2015), and associated with changes in dominance of taxonomic groups of phytoplankton from diatoms to dinoflagellates (Tenenbaum et al, 2010;Lange et al, 2014). This was seen in scenarios iii and iv, periods under the influence of meltwater, when there was codominance between diatoms (e.g., Corethron pennatum, Thalassiosira cf.…”

Plankton Structure of Shallow Coastal Zone at Admiralty Bay, King George Island, West Antarctic Peninsula (Wap) During Early Summer/2010: Pico, Ultra and Microplankton and Chlorophyll Biomass

“…Based on these facts since 2009 new approaches to phytoplankton monitoring have been established, including the analysis of size-fractioned pigments by spectro uorometry, and the analysis of density and biovolume of pico-and ultraplankton by epi uorescence microscopy, and furthermore through a higher sampling frequency e ort (Tenenbaum et al, 2011a). Additionally, the composition of microphytobenthos species will be carried out to study the e ects of environmental changes on this community in the nearshore Antarctic ecosystem (Tenenbaum et al, 2011b). In the present study we show the results from early summer obtained during the OPERANTAR XXIX, December 2010.…”

Microplankton Community Structure of the Shallow Coastal Zone at Admiralty Bay, Antarctica: Comparison Between Two Consecutive Austral Summers

“…Additionally, the composition of microphytobenthos species has been carried out to study the effects of environmental changes on this community in the nearshore Antarctic ecosystem (Tenenbaum et al, 2011b). samples) (Tenório et al, 2011).…”