Quality of the surface sediments of the northern coast of the Gulf of Finland, Baltic Sea

Abstract. Stratification plays an essential role in the marine system. The shallow mixed layer is one of the preconditions for the enhanced primary production in the ocean. The general understanding is that the mixed layer is well deeper than the euphotic zone in the Baltic Sea during winter. In this work, we demonstrate the wintertime stratification is a common phenomenon in the Gulf of Finland. Shallow haline stratification at the depth comparable to the euphotic zone depth forms in late January–early February. Stratification is evoked by the positive buoyancy flux created by the westward advection of riverine water along the northern coast of the gulf. Fresher water and haline stratification appeared approximately one month later in the southern part of the gulf. The phenomena can occur in the whole gulf and also without ice. Chl a concentration and phytoplankton biomass in winter can be comparable to mid-summer. The limiting factor for phytoplankton bloom in winter is likely insufficient solar radiation.

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Storm surges in the Gulf of Finland of the Baltic Sea

Vestnik of Saint Petersburg University Earth Sciences ◽

10.21638/spbu07.2021.408 ◽

2021 ◽

Vol 66 (4) ◽

Author(s):

Evgeny A. Zakharchuk ◽

◽

Vladimir N. Sukhachev ◽

Natal'ia A. Tikhonova ◽

◽

...

Keyword(s):

Baltic Sea ◽

Sea Level ◽

Atmospheric Pressure ◽

Storm Surges ◽

Gulf Of Finland ◽

Northern Coast ◽

The Baltic Sea ◽

Wide Range ◽

The Baltic ◽

The Gulf Of Finland

The characteristics of storm surges in different regions of the Gulf of Finland in the second half of the XX and the beginning of the XXI centuries were investigated on the basis of tide gauge measurements of sea level, instrumental observations of the wind and data from the reanalysis of meteorological fields. A criterion for identifying storm surges, taking into account spatial changes in their intensity, is proposed. The results indicate that depending on the year and the location of the station, the number of storm surges varies in the Gulf of Finland in a wide range: from 0 - 1 to 16 - 52 cases per year. The average duration of storm surges varies from 6.7 to 9.0 hours, and the maximum reaches 26 to 96 hours. Shown that in recent decades, in most regions, there has been a tendency towards a decrease in the number of storm surges, their dispersion and sea level maximum. The distributions of the probabilities of wind and atmospheric pressure during storm surges are given. Estimates of two-dimensional probability densities indicate that during storm surges, winds blowing from the west and southwest with speeds of 4-13 m / s are most likely. At the northern coast and at the top of the bay, the most probable values of atmospheric pressure during storm surges are 995 hPa. On the southern coast of the Gulf of Finland, atmospheric pressure values of 1005 - 1015 hPa are most likely. The results obtained indicate that the atmospheric pressure over the Gulf of Finland during storm surges is not very low. This is due to the fact that the trajectories of the centers of cyclones causing storm surges pass north of the Gulf of Finland. Analysis of meteorological information also showed the presence of significant negative trends in interannual variations in the dispersion of the horizontal atmospheric pressure gradient, average values and maximums of wind speed. It is concluded that the revealed changes in the characteristics of storm surges are associated with a decrease in the intensity of cyclogenesis in the atmosphere over the Baltic Sea in recent decades.

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The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea

Ocean Science ◽

10.5194/os-16-1475-2020 ◽

2020 ◽

Vol 16 (6) ◽

pp. 1475-1490

Author(s):

Taavi Liblik ◽

Germo Väli ◽

Inga Lips ◽

Madis-Jaak Lilover ◽

Villu Kikas ◽

...

Keyword(s):

Baltic Sea ◽

Mixed Layer ◽

Phytoplankton Bloom ◽

Marine Ecosystem ◽

Euphotic Zone ◽

Gulf Of Finland ◽

Limiting Factor ◽

Northern Coast ◽

Prevailing Wind Direction ◽

The Gulf Of Finland

Abstract. Stratification plays an essential role in the marine ecosystem, with a shallow mixed layer being one of the preconditions for enhanced primary production in the ocean. In the Baltic Sea, the general understanding is that the upper mixed layer (UML) is well below the euphotic zone in winter. In this study, we demonstrate that wintertime shallow stratification is common in the Gulf of Finland and it forms at a depth comparable to the euphotic zone in January–February. The onset of restratification is likely associated with the annual cycle of westerly winds, which ease off in late January–early February. Stratification is first invoked along the northern coast by the westward advection of riverine water forced by easterly winds and is expanded to the south when the prevailing wind direction changes from an easterly to a westerly direction. Haline stratification emerges approximately 1 month later in the southern part of the gulf. Winter restratification can occur in the entire gulf and also in the absence of ice; thus, it is a regular seasonal feature in the area. Interannual variations in the wintertime UML correspond with variations in the North Atlantic Oscillation. Chlorophyll a concentrations in winter can be comparable to mid-summer; the limiting factor for phytoplankton bloom in winter is likely insufficient solar radiation.

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Coastal-Fish Communities along the Northern Coast of the Gulf of Finland, Baltic Sea: Responses to Salinity and Eutrophication

International Review of Hydrobiology ◽

10.1002/1522-2632(200011)85:5/6<687::aid-iroh687>3.0.co;2-4 ◽

2000 ◽

Vol 85 (5-6) ◽

pp. 687-696 ◽

Cited By ~ 18

Author(s):

Antti Lappalainen ◽

Alexander Shurukhin ◽

Gregory Alekseev ◽

Jukka Rinne

Keyword(s):

Baltic Sea ◽

Fish Communities ◽

Gulf Of Finland ◽

Northern Coast ◽

Coastal Fish ◽

The Gulf Of Finland

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The mussel caging approach in assessing biological effects of wastewater treatment plant discharges in the Gulf of Finland (Baltic Sea)

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2015.06.024 ◽

2015 ◽

Vol 97 (1-2) ◽

pp. 135-149 ◽

Cited By ~ 21

Author(s):

Raisa Turja ◽

Kari K. Lehtonen ◽

Axel Meierjohann ◽

Jenny-Maria Brozinski ◽

Emil Vahtera ◽

...

Keyword(s):

Wastewater Treatment ◽

Baltic Sea ◽

Wastewater Treatment Plant ◽

Biological Effects ◽

Treatment Plant ◽

Gulf Of Finland ◽

The Gulf Of Finland

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An integrated simulation model to evaluate national measures for the abatement of agricultural nutrients in the Baltic Sea

Agricultural and Food Science ◽

10.23986/afsci.5951 ◽

2009 ◽

Vol 18 (3-4) ◽

pp. 440-459 ◽

Cited By ~ 4

Author(s):

K. HYYTIÄINEN ◽

H. AHTIAINEN ◽

J. HEIKKILÄ

Keyword(s):

Water Quality ◽

Simulation Model ◽

Baltic Sea ◽

Arable Land ◽

Gulf Of Finland ◽

Nutrient Loads ◽

The Baltic Sea ◽

The Baltic ◽

Bothnian Bay ◽

The Gulf Of Finland

This study introduces a prototype model for evaluating measures to abate agricultural nutrients in the Baltic Sea from a Finnish national perspective. The stochastic simulation model integrates nutrient dynamics of nitrogen and phosphorus in the sea basins adjoining the Finnish coast, nutrient loads from land and other sources, benefits from nutrient abatement (in the form of recreation and other ecosystem services) and the costs of agricultural abatement activities. The aim of the study is to present the overall structure of the model and to demonstrate its potential using preliminary parameters. The model is made flexible for further improvements in all of its ecological and economic components. The results of a sensitivity analysis suggest that investments in reducing the nutrient load from arable land in Finland would become profitable only if the neighboring countries in the northern Baltic committed themselves to similar reductions. Environmental investments for improving water quality yield the highest returns for the Bothnian Bay and the Gulf of Finland, with smaller returns for the Bothnian Sea. Somewhat surprisingly, in the Bothnian Bay the abatement activities become profitable from the national viewpoint, because the riverine loads from Finland represent a high proportion of the total nutrient loads. In the Gulf of Finland, this proportion is low, but the size of the coastal population benefiting from improved water quality is high.;

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Assessment of the quality of freshwater ecosystems based on the functional condition of bivalved mollusks

Водные ресурсы ◽

10.31857/s0321-0596462214-224 ◽

2019 ◽

Vol 46 (2) ◽

pp. 214-224

Author(s):

S. V. Kholodkevich ◽

A. N. Sharov ◽

G. M. Chuiko ◽

T. V. Kuznetsova ◽

M. V. Gapeeva ◽

...

Keyword(s):

Functional State ◽

Rybinsk Reservoir ◽

Functional Condition ◽

Freshwater Ecosystems ◽

Gulf Of Finland ◽

Bivalve Mollusks ◽

Accumulation Of Metals ◽

The Rybinsk Reservoir ◽

The Gulf Of Finland

An approach is proposed for ranking the quality of freshwater ecosystems by the state of bivalve mollusks living in them. Cardioactivity indicators and accumulation of metals in the tissues of the mollusks from various waters of the eastern part of the Gulf of Finland and the Rybinsk Reservoir were used to characterize the ecosystems, and an original hyperosmotic test was used to analyze the functional state of the mollusks.

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Three new chrysophycean stomatocysts with long spines from the Gulf of Finland, Baltic Sea

Phytotaxa ◽

10.11646/phytotaxa.528.4.4 ◽

2021 ◽

Vol 528 (4) ◽

pp. 255-260

Author(s):

SVETLANA N. SHADRINA

Keyword(s):

Baltic Sea ◽

Working Group ◽

Gulf Of Finland ◽

Sem Micrographs ◽

Biological Affinity ◽

The Gulf Of Finland

Three new morphotypes of chrysophycean stomatocysts with long spines are described following International Statospore Working Group (ISWG) guidelines and illustrated by SEM micrographs. Differences of our new morphotypes from known stomatocysts are discussed. Their biological affinity is currently unknown.

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