Counts and abundance of macrozoobenthic organisms settled in artificial soft sediment at Brandal, Kongsfjorden, Spitsbergen

In the Arctic the currently observed rising air temperature results in more frequent calving of icebergs. The latter are derived from tidewater glaciers. Arctic macrozoobenthic soft-sediment communities are considerably disturbed by direct hits and sediment reallocation caused by iceberg scouring. With the aim to describe the primary succession of macrozoobenthic communities following these events, scientific divers installed 28 terracotta containers in the soft-sediment off Brandal (Kongsfjorden, Svalbard, Norway) at 20 m water depth in 2002. The containers were filled with a bentonite-sand-mixture resembling the natural sediment. Samples were taken annually between 2003 and 2007. A shift from pioneering species (e.g. Cumacea: Lamprops fuscatus) towards more specialized taxa, as well as from surface-detritivores towards subsurface-detritivores was observed. This is typical for an ecological succession following the facilitation and inhibition succession model. Similarity between experimental and non-manipulated communities from 2003 was significantly highest after three years of succession. In the following years similarity decreased, probably due to elevated temperatures, which prevented the fjord-system from freezing. Some organisms numerically important in the non-manipulated community (e.g., the polychaete Dipolydora quadrilobata) did not colonies the substrate during the experiment. This suggests that the community had not fully matured within the first three years. Later, the settlement was probably impeded by consequences of warming temperatures. This demonstrates the long-lasting effects of severe disturbances on Arctic macrozoobenthic communities. Furthermore, environmental changes, such as rising temperatures coupled with enhanced food availability due to an increasing frequency of ice-free days per year, may have a stronger effect on succession than exposure time.

Abundance of microplankton in the eastern Mediterranean Sea in March and April 2008 during SES_GR1

The dataset is based on samples taken from 12 stations in Southern Aegean Sea, Northern Aegean Sea, Ionian Sea and Libyan Sea during March-April 2008. 12 Niskin bottles (8lt) made by PVC with rubber coated o rings and stainless steel ss springs. Seawater samples (150 ml) were collected from selected depths of the water column (2, 20, 50, 75, 100 m) for the identification and enumeration of phytoplankton cells (>=5 µm). The samples were fixed with Lugol solution and concentrated to 25 ml by sedimentation. Phytoplankton species abundance was determined with an inverted light microscope (OLYMPUS IX70) according to the Utermohl method (Utermohl, 1958).

Abundance and biomass of phytoplankton in the western part of the Black Sea during the R/V Akademik cruise Ak082001 in August 2001

The dataset is composed of 41 samples from 10 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profile and the in situ fluorometer readings: surface, temperature, salinity and fluorescence gradients and 1 m above the bottom. At some stations phytoplankton net samples (20 µm mesh-size) were collected to assist species biodiversity examination. The samples (1l sea water) were preserved in 4% buffered to pH 8-8.2 with disodiumtetraborate formaldehyde solution and stored in plastic containers. On board at each station few live samples were qualitatively examined under microscope for preliminary analysis of taxonomic composition and dominant species. The taxon-specific phytoplankton abundance samples were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). Total phytoplankton abundance was calculated as sum of taxon-specific abundances. Total phytoplankton biomass was calculated as sum of taxon-specific biomasses. The cell biovolume was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).

Abundance and biomass of phytoplankton in the western part of the Black Sea during Branimir Ormanov cruise BO092000 in September 2000

The samples were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). Taxon-specific phytoplankton abundance and biomass were analysed by Moncheva S., B. Parr, 2005. Manual for Phytoplankton Sampling and Analysis in the Black Sea. The cell biovolume was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).