scholarly journals Modelling the Visibility of Baltic-Type Crude Oil Emulsion Dispersed in the Southern Baltic Sea

2021 ◽  
Vol 13 (10) ◽  
pp. 1917
Author(s):  
Emilia Baszanowska ◽  
Zbigniew Otremba ◽  
Jacek Piskozub

This paper analyses the radiance reflectance modelling of a sea area and the case of a water column polluted with an oil emulsion in relation to various depths of the occurrence of an oil-in-water emulsion in all azimuth and zenith angles. For the radiance reflectance modelling, the simulation of large numbers of solar photons in water was performed using a Monte Carlo simulation. For the simulations, the optical properties of seawater for the open sea typical of the southern Baltic Sea were used and Petrobaltic-type crude oil (extracted in the Baltic Sea) was added. Oil pollution in the sea was considered for oil droplet concentrations of 10 ppm, which were optically represented by spectral waveforms of absorption and scattering coefficients, as well as by angular light scattering distribution determined using the Mie theory. The results of the radiance reflectance modelling in the whole spectrum of both angles, azimuth and zenith, allowed us to select 555 nm as the optimal wavelength for oil emulsion detection. Moreover, the parameter contrast was defined and determined using radiance reflectance results for eight light wavelengths in the range of 412-676 nm. The contrast is discussed in relation to the various thicknesses of polluted water layers. Changes in contrast for a thickness layer 5 m under the sea surface were noted, whereas for thicker layers the contrast remained unchanged.

2021 ◽  
Vol 13 (19) ◽  
pp. 3927
Author(s):  
Zbigniew Otremba ◽  
Jacek Piskozub

Information was obtained on the possibility of detecting oil-in-water emulsions located under the sea based on the modelling of the directional distribution of the radiance field above the water surface. The optical sea model used applies to the southern Baltic Sea, while the oil emulsion model is based on the optical properties of crude oil extracted in this region of the sea. The analyses were carried out while taking into account eight wavelengths in the range 412–676 nm, assuming different thicknesses of the layer contaminated with oil. The most favourable combination of two wavelengths (555/412 nm) for the determination of an index related to the polluted sea area compared to the same index for oil-free water (difference index) was identified, the value of which is indicative of the presence of the oil emulsion in water. Changes in the difference index depending on the viewing direction are shown for almost the entire upper hemisphere (zenith angles from 0° to 80°). The observation directions for which the detection of emulsions should be the most effective are shown.


Author(s):  
Małgorzata Leśniewska ◽  
Małgorzata Witak

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)The palaeoenvironmental changes of the south-western part of the Gulf of Gdańsk during the last 8,000 years, with reference to the stages of the Baltic Sea, were reconstructed. Diatom analyses of two cores taken from the shallower and deeper parts of the basin enabled the conclusion to be drawn that the microflora studied developed in the three Baltic phases: Mastogloia, Littorina and Post-Littorina. Moreover, the so-called anthropogenic assemblage was observed in subbottom sediments of the study area.


2022 ◽  
Vol 14 (2) ◽  
pp. 247
Author(s):  
Zbigniew Otremba ◽  
Jacek Piskozub

The article presents the results of simulations that take into account the optical parameters of the selected sea region (from literature data on the southern Baltic Sea) and two optically extreme types of crude oil (from historical data) which exist in the form of a highly watered-down oil-in-water emulsion (10 ppm). The spectral index was analyzed based on the results of modeling the radiance reflectance distribution for almost an entire hemisphere of the sky (zenith angle from 0 to 80°). The spectral index was selected and is universal for all optically different types of oil (wavelengths of 650 and 412 nm). The possibility of detecting pollution in the conditions of the wavy sea surface (as a result of wind of up to 10 m/s) was studied. It was also shown that if the viewing direction is close to a direction perpendicular to the sea surface, observations aimed at determining the spectral index are less effective than observations under the zenith angle of incidence of sunlight for all azimuths excluding the direction of sunlight’s specular reflection.


2018 ◽  
Vol 33 (1) ◽  
pp. 9-15
Author(s):  
Iwona Zabroś ◽  
Marlena Mioskowska

The Baltic Sea is characterized by a seasonal variation of phytoplankton structure. These organisms are particularly sensitive to changes in various environmental parameters. Cyclic, recurring annually fluctuation of species composition, abundance and biomass of phytoplankton is a consequence of these changes. Spatial and temporal variability of particular groups of phytoplankton is not the same in different areas of the Baltic Sea. The purpose of this work was to determine the spatial and temporal distribution of phytoplankton in three chosen areas of the coastal zone of the southern Baltic Sea (Ustka, Poddąbie and Rowy) in the period of November 2014 - September 2016. Mean values of abundance and biomass of phytoplankton for the surveyed areas were typical for this type of coastal waters. In each of the surveyed areas the same dominat species in terms of the abundance and biomass were observed. A growth of diatoms was recorded only in the area of Ustka, which could have been caused by the inflow of river waters. Seasonal surveys of phytoplankton indicated that in the case of the studies regarding this parameter – taxonomic composition, abundance and biomass in the same surveyed area were similar at the three research stations (e.g. 75-80%), depending on the season of the year. On this basis, it was concluded that, whether carrying out the monitoring of phytoplankton or planned investments, the sample collection frequency had a greater significance than the number of research stations.


AMBIO ◽  
2008 ◽  
Vol 37 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Adam Sokołowski ◽  
Krzysztof Pawlikowski ◽  
Maciej Wołowicz ◽  
Pascale Garcia ◽  
Jacek Namieśnik

Author(s):  
Diana Dziaduch

AbstractDiet composition of two commercial fish species, herring and cod, were studied in some regions (mainly Gda’nsk and Bornholm Basins, and the Polish coast) of the southern Baltic Sea in 2007 and 2008. Herring is the dominant zooplanktivorous species in the ecosystem of the Baltic Sea, but apart from mesoplanktonic organisms it also eats macroplanktonic and benthic species in considerable amount. The diet of cod consists of fish and crustaceans from pelagic, hyperbenthic and benthic habitats. The feeding preferences of fish indirectly reflect changes in the whole food chain in the Baltic Sea. This research focuses specifically on these invertebrate species, which are eliminated from the environment by most of the ichthyofauna of this region. The aim of this research is to examine the role of invertebrate organisms belonging to Crustacea in the diet of herring and adult cod to supply updated results about feeding of these fish as little data have been collected since the 1990s. The present study is a preliminary survey and results can not be considered conclusive. The restricted numbers of analyzed stomachs of fish and selected seasons of the year addressed in this paper are a starting point for further studies with a larger scope. In this study, 20 to 90% of herring had empty stomachs. Mesozooplankton dominated the diets of small and large herring. Mysidacea, which were historically important prey for herring, are now scarce and have been replaced by planktonic Amphipoda. In the case of cod, consumption of Mysidacea has never been as low as in this study. As for other invertebrate prey, the benthic isopod Saduria and Crangon shrimp achieved the highest amount by number and weight. These results show distinct changes in diet when compared to previous investigations and require verification at a larger spatial scale.


2013 ◽  
Vol 88 (2) ◽  
pp. 237-246 ◽  
Author(s):  
K. Nadolna ◽  
M. Podolska

AbstractIn the present investigation a sample of 490 cod (Gadus morhua) was examined from three regions in the southern Baltic Sea (the Polish Exclusive Economic Zone, EEZ). Three species of anisakid nematodes with zoonotic potential, namely species of Contracaecum, Anisakis and Pseudoterranova, were found in the liver of cod, with Contracaecum being the most dominant species. The prevalence of infection was highest in the Western Baltic (22.5%) compared to the Central Baltic (10.4%) and the Gulf of Gdansk (3.4%). Generalized linear models (GLMs) were applied to analyse the prevalence of infection with Anisakis sp. and Contracaecum sp. relative to biological and spatial parameters. The effect of the sampling region, age and body length of the fish were significant in both GLMs. The effect of region was higher in the Western Baltic than in other regions. The prevalence of infection was correlated with the length of the fish and was higher in adult compared with sub-adult fish. These results suggest that the prevalence of infection with anisakid nematodes (especially Contracaecum sp.) in cod sampled in Polish waters of the Baltic Sea has significantly increased compared with previous studies undertaken over the past few decades.


2021 ◽  
Vol 9 (9) ◽  
pp. 949
Author(s):  
Ulf Karsten ◽  
Kana Kuriyama ◽  
Thomas Hübener ◽  
Jana Woelfel

Benthic diatom communities dominate sheltered shallow inner coastal waters of the atidal Southern Baltic Sea. However, their photosynthetic oxygen production and respiratory oxygen consumption is rarely evaluated. In the Baltic Sea carbon budget benthic diatom communities are often not included, since phytoplankton is regarded as the main primary producer. Therefore, two wind-protected stations (2–49-cm depths) were investigated between July 2010 and April 2012 using undisturbed sediment cores in combination with planar oxygen optodes. We expected strong fluctuations in the biological activity parameters in the incubated cores over the course of the seasons. The sediment particles at both stations were dominated by fine sand with a median grain size of 131–138 µm exhibiting an angular shape with many edges, which were less mobile compared to exposed coastal sites of the Southern Baltic Sea. These sand grains inhabited dense communities of rather small epipsammic diatoms (<10 µm). Chlorophyll a as a biomass parameter for benthic diatoms fluctuated from 64.8 to 277.3-mg Chl. a m−2 sediment surface. The net primary production and respiration rates exhibited strong variations across the different months at both stations, ranging from 12.9 to 56.9 mg O2 m−2 h−1 and from −6.4 to −137.6 mg O2 m−2 h−1, respectively. From these data, a gross primary production of 13.4 to 59.5 mg C m−2 h−1 was calculated. The results presented confirmed strong seasonal changes (four-fold amplitude) for the activity parameters and, hence, provided important production biological information for sheltered sediments of the Southern Baltic Sea. These data clearly indicate that benthic diatoms, although often ignored until now, represent a key component in the primary production of these coastal habitats when compared to similar studies at other locations of the Baltic Sea and, hence, should be considered in any carbon budget model of this brackish water ecosystem.


2020 ◽  
Author(s):  
Ove Pärn ◽  
Gennadi Lessin ◽  
Adolf Stips

AbstractIn this study, the effects of sea ice and wind speed on the timing and composition of phytoplankton spring bloom in the central and southern Baltic Sea are investigated by a hydrodynamic–biogeochemical model and observational data. The modelling experiment compared the results of a reference run in the presence of sea ice with those of a run in the absence of sea ice, which confirmed that ecological conditions differed significantly for both the scenarios. It has been found that diatoms dominate the phytoplankton biomass in the absence of sea ice, whereas dinoflagellates dominate the biomass in the presence of thin sea ice. The study concludes that under moderate ice conditions (representing the last few decades), dinoflagellates dominate the spring bloom phytoplankton biomass in the Baltic Sea, whereas diatoms will be dominant in the future as a result of climate change i.e. in the absence of sea ice..


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