Seasonal Variability of Bioluminescence and Abundance of the Dinoflagellate Noctiluca scintillans in the Arabian Sea.

Bioluminescence is a functional property used by many marine organisms for multilateral communications. In the Arabian Sea, the dinoflagellate Noctiluca scintillans (Macartney) Kofoid and Swezy, 1921, contributes gradually to the bioluminescent potential (BP) of the phytoplankton community. Experiments, field sampling, and remote sensing were employed, to estimate the seasonal variation of the BP and the abundance of cells in the northwestern Arabian Sea.

Research into bioluminescence of the Black Sea ctenophores Pleurobrachia pileus O.F. Müller, 1776.

The work presents the findings of the laboratory and in situ studies of ctenophore Pleurobrachia pileus O.F. Müller, 1776 which have shown that this species has bioluminescent properties.

Bioluminescent eddies of the World Ocean.

Mesoscale eddies of the ocean (with a characteristic diameter of about 100 km and a life time-span of about several weeks) are habitats of plankton organisms, many of which are bioluminescent. The spatial heterogeneity of bioluminescence of the upper mixed layer associated with the impact of mesoscale eddies is poorly studied. The 45-year historical data set was retrieved, in order to select the bathy-photometric surveys carried out in the form of station grids and transects across eddies.

Field studies of bioluminescence in Bransfield Strait in 2022.

In January 2022, during scientific cruise 87 on the RV Academic Mstislav Keldysh in the Atlantic sector of the Southern Ocean, three hydrobiophysical cross-sections were performed in the Bransfield Strait. Bioluminescent signals were measured in a layer of 0-200 m at each of the 24 stations located at three sites. For the first time, a new hydrobiological system 'Salpa MA +' was used, which made it possible to obtain novel data in the photic layer of the studied water area.

Bioluminescence of the tropical Indian Ocean: a multiple-scale variation.

Large-scale surveys represented by 5800 bathymetric casts in the western Indian Ocean (0-22 N, 54-58 E), elucidated the 10-fold variation of the bioluminescent potential (BP) in the upper mixed layer, during the winter (north-east) monsoon season. The mesoscale survey in February 2017 consisted of 26 drift stations (4 N-3 S, 65-68 E) on which 5-10 bathymetric casts were deployed down to 60 m. The maximal BP was associated with the periphery of a cyclonic eddy.

Field studies of bioluminescence in the Antarctic sector of the Atlantic Ocean in 2002 and 2020.

In this work, IBSS materials on seawater bioluminescence intensity changes in the Atlantic sector of the Antarctic Ocean (the Weddell Sea area) with an interval of almost 20 years are presented. Data were obtained using a single instrument, the hydrobiophysical system Salpa-M, in the area of 50-63°S, 62-49°W in March 2002 (183 soundings at 45 stations during cruise 7 on RV Gorizont) and in February 2020 (122 soundings at 18 stations during cruise 79 on RV Academic Mstislav Keldysh). The bioluminescence studies were coupled with the simultaneous measurement of temperature, electrical conductivity, and photosynthetically active radiation, and they were compared with the data from processing plankton samples.

Bioluminescence of ctenophores near the boundary of oxygen-depleted waters at the redoxcline of the Black Sea.

Vertical distribution of ctenophores near the boundary of oxygen-depleted waters of the Black Sea redoxcline was studied by use of video observations with real-time water sampling, horizontal MultiNet towing, and soundings using bathyphotometers with simultaneous vertical plankton net sampling. The results of the study showed for the first time that the daytime accumulation of ctenophores above the upper boundary of the suboxic zone changes the biophysical properties of the medium, causing an increase in the daytime intensity of bioluminescence near the redoxcline. The dynamics of this glow is in antiphase to that in the surface layers, where it is associated with the bioluminescence of phytoplankton.