scholarly journals New Approach for Analyzing Marine Ecosystem Structure Using Bayesian Networks

2021 ◽  
Vol 21 (6) ◽  
pp. 1-8
Author(s):  
Denis Krivoguz ◽  
◽  
Sergey Chernyi ◽  
Artur Manukov ◽  
◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Bayesian Networks ◽  
Black Sea ◽  
Net Primary Production ◽  
Marine Ecosystem ◽  
Water Environment ◽  
Dynamic Bayesian Networks ◽  
The Black Sea ◽  
Ecosystem Structure ◽  
Natural Systems

Aquatic ecosystems of the Black Sea are complex multiparametric systems with a hierarchical structure. Thus, the main goal of our research was to investigate possibilities of using Bayesian networks to study the structure fo the natural systems in the Black Sea. We used CMEMS Black Sea environmental dataset, which consists of 7 different variables, that, in our opinion, can describe structural relations in the Black Sea ecosystem -- sea surface temperature and salinity, concentrations of nitrates and phosphates, amount of chlorophyll-a and net primary production and also dissolved oxygen concentration. We think, that these variables can generally define interactions in water environment of the Black Sea, organisms, that live there and human activity. As a modelling result, we receive a structure of environmental variables interactions. At the top of this structure is a dissolved oxygen, as a final result of the ecosystem functioning. Further, we think it's more appropriate to use Dynamic Bayesian networks for investigation of spatio-temporal changes to distinguish main drivers of changes and provide more balanced management of natural territories.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

scholarly journals A study of long-term changes in Black Sea ecosystems based on data assimilation of remote measurements in a numerical model

2019 ◽  
Vol 46 (1) ◽  
pp. 58-69
Author(s):  
V. L. Dorofeev ◽  
L. I. Sukhikh
Keyword(s):  
Black Sea ◽  
Marine Ecosystem ◽  
Three Dimensional ◽  
The Black Sea ◽  
Regular Grid ◽  
Remote Measurements ◽  
Biogeochemical Parameters ◽  
Color Scanner

Herein, we present a simulation of the dynamics of Black Sea ecosystems using a three-dimensional interdisciplinary model that assimilates satellite color scanner measurements. Calculations were performed for the fifteen years from 1998 and a set of 3-d biogeochemical fields of the Black Sea were generated on a regular grid with a discreteness time of 1 day. Analyses of core biogeochemical parameters of the marine ecosystem were then performed. The qualities of received fields were evaluated using comparisons with existing data from in situ measurements.

scholarly journals Ecological interrelations of Rapana venosa (Gastropoda: Muricidae) with ichthyofauna in the Black Sea

2016 ◽  
Vol 1 (4) ◽  
pp. 76-77
Author(s):  
I. P. Bondarev
Keyword(s):  
Black Sea ◽  
Marine Ecosystem ◽  
Fish Fauna ◽  
The Black Sea ◽  
Sandy Bottom ◽  
Rapana Venosa ◽  
New Information ◽  
Bottom Zone

Systematic monitoring of ecologically significant species – predatory mollusc Rapana venosa Valenciennes, 1846 populations – is an important part of the Black Sea monitoring. The study of the role of R. venosa in contemporary marine ecosystem is of considerable interest. In June-September 2015-2016 the study of consorting relations of rapana was conducted in situ with a parallel sampling by diver. In the course of research new information about the interaction of R. venosa with the fish fauna has been obtained. Of particular importance for fishes is the presence of rapana in the sandy bottom zone, where there are no natural shelters, and food resources are limited. The most important for the fish is the presence on the rapana shells of algal fouling and epiphyton. The shells of invader – R. venosa – and its fouling create additional opportunities for the survival of some fish fauna representatives juveniles of the Black Sea. The data obtained extend the concepts of ecological role of mollusc – invader R. venosa, as well as the ecology and ethology of several fish species.

Causes and Consequences of the Black Sea Ecosystem Pollution with Petroleum Products

2020 ◽  
pp. 29-44
Author(s):  
Bogdan Cioruța ◽  
Diana Mădăras ◽  
Mirela Coman
Keyword(s):  
Protected Areas ◽  
Cultural Values ◽  
Black Sea ◽  
Marine Protected Areas ◽  
Oil Pollution ◽  
Marine Ecosystem ◽  
Marine Ecosystems ◽  
Petroleum Products ◽  
The Black Sea ◽  
Oil Pipeline

Until the beginning of the 21st century concerns related to the management of protected areas have been reduced to the voluntary initiatives of nature lovers, rarely materializing in specific conservation measures carried out by the authorities or administrators of those areas. As the concern for the management of protected areas is relatively new in Romania and the information related to this subject is relatively scarce, especially those regarding marine ecosystems, we considered necessary this study on the management of marine protected areas in relation to oil pollution. Marine protected areas, in particular, delimited as areas where the main purpose is the protection of nature and cultural values, are important for all segments of society. They have great potential to become models of harmonious society development, promoting more than other protected areas the sustainable resource management. At the same time, the management measures promoted, sometimes imposed, can affect the communities inside or in the immediate vicinity of the areas, and can significantly influence the development of the economy. Recently (as a reference 1970-2020), the pollution of the marine environment with petroleum products has gained dramatic accents. The maritime transport of oil, the exploration and exploitation of marine deposits, their processing in refineries located in the vicinity of the coastal area, to which are added other anthropogenic activities, have generated and still generate a number of risk factors, which involve numerous pollution incidents. Navigation accidents of large oil tanks or incidents at offshore drilling rigs caused, in the same period, major environmental disasters, with the most severe consequences. Marine ecosystems in polluted regions have thus suffered major losses and disturbances, which have been felt for a long time. Through this paper we aim to review some aspects of oil pipeline pollution of the Planetary Ocean, respectively the associated pollution in the Black Sea ecosystem. Following the analyzes carried out on the basis of the data from the consulted literature, as well as following other observations, we came to the conclusion that the protected areas associated with the Black Sea, as well as the marine ecosystem itself, are far from being affected by such accidents.

scholarly journals Biodiversity in the Black Sea - ecological Study from the Perspective of Romanian philately

2021 ◽  
pp. 35-50
Author(s):  
Bogdan-Vasile Cioruța ◽  
Alexandru Leonard Pop ◽  
Mirela Coman
Keyword(s):  
Protected Areas ◽  
Cultural Values ◽  
Black Sea ◽  
Marine Protected Areas ◽  
General Public ◽  
Ecological Study ◽  
Marine Ecosystem ◽  
Marine Ecosystems ◽  
The Black Sea ◽  
Postage Stamps

As the concern for the management of protected areas is relatively new in Romania, and the information related to this topic is relatively scarce, especially those on marine ecosystems, we considered necessary this study on the management of marine protected areas with specific biodiversity illustrated by philately. Marine protected areas, in particular, delimited as areas where the main purpose is the protection of nature and cultural values, are important for all segments of society. Through this paper, we aimed to review several aspects, ecological and philatelic alike, regarding the specific biodiversity of the Black Sea ecosystem. Following the analyzes performed on account of the data from the consulted specialized literature (in the form of postage stamps, FDCs, occasional envelopes, and maximum postcards, but also other philatelic effects), as well as as a result of other observations (with catalogs and sites with philatelic content), we concluded that the biodiversity of the Black Sea, as well as the marine ecosystem itself, are relatively well represented in Romanian philately. The four philatelic issues illustrate crustaceans, mollusks, corals, and anemones, but also other species, all being to the liking of the general public in terms of information and promotion.

The Influence of Air Temperature on the Quality Parameters of the Black Sea Coastal Waters

2019 ◽  
pp. 62-85
Author(s):  
Sabina Zăgan ◽  
Mihaela-Greti Chiţu
Keyword(s):  
Black Sea ◽  
Air Temperature ◽  
Sea Water ◽  
Marine Ecosystem ◽  
Ambient Air ◽  
Superficial Layer ◽  
Quality Parameters ◽  
The Black Sea ◽  
Air Temperatures ◽  
Physical And Chemical

In this chapter, the authors point out the connection between some physical and chemical parameters of the Black Sea water under extreme air temperatures. In this context, the period from 2006 to 2012 was chosen as the study period, because it is characterized by very high values of air temperature, which significantly affect not only the quality of the Black Sea water in the superficial layer but also the marine ecosystem and life. Some quality parameters as water temperatures, oxygen regime or the degree of eutrophication have been collected and analyzed and they show noticeable variations relative to ambient air temperature changes, mainly if they are determined on the surface layer.

scholarly journals The Holocene history of the NE Black Sea and surrounding areas: An integrated record of marine and terrestrial palaeoenvironmental change

The Holocene ◽  
2019 ◽  
Vol 29 (4) ◽  
pp. 648-661 ◽  
Author(s):  
Fabienne Marret ◽  
Lee R Bradley ◽  
Pavel E Tarasov ◽  
Elena V Ivanova ◽  
Maria A Zenina ◽  
...  
Keyword(s):  
Black Sea ◽  
Deciduous Forest ◽  
Land Use Changes ◽  
Water Environment ◽  
Early Holocene ◽  
The Black Sea ◽  
Pollen Record ◽  
Temperate Deciduous Forest ◽  
Black Sea Region ◽  
Palaeoenvironmental Change

Here we present an almost complete and integrated Holocene record of marine and terrestrial palaeoenvironmental change from the NE shelf of the Black Sea. A dinoflagellate cyst record used to reconstruct Holocene sea-surface conditions highlights that the NE shelf was a brackish water environment, with a minimum salinity of 7 psu in the early-Holocene before changing at a gradual rate to a more saline environment with maximum salinities of ~18 psu being reached around 3 cal. ka. A warming phase was detected from 6 cal. ka BP, with warmest conditions between 3 and 2.5 cal. ka BP. A pollen record is used to examine the major climate and land-use changes in the eastern Black Sea region. Biome reconstructions show that the temperate deciduous forest dominates throughout the record, although with an overall decline. From early-Holocene to the first hiatus around ~9 cal. ka BP, Pinus pollen dominates, while taxa representing a mixed oak-hornbeam-beech forest are less abundant, indicating relatively cool and dry conditions. Between ~7.9 and ~6.1 cal. ka BP, a thermophilous deciduous forest established, suggesting an overall warming trend and humid conditions. From 4 cal. ka BP, Pinus dominates the pollen record, accompanied by an increase of herbs, implying an opening of the landscape, which would coincide with the beginning of the Meghalayan Age. The integrated record of the marine and terrestrial climate indicators supports the notion that this change in landscape may have been triggered by a combination of warmer and drier conditions and human activities in this region.

scholarly journals Projected decreases in future marine export production: the role of the carbon flux through the upper ocean ecosystem

2016 ◽  
Vol 13 (13) ◽  
pp. 4023-4047 ◽  
Author(s):  
Charlotte Laufkötter ◽  
Meike Vogt ◽  
Nicolas Gruber ◽  
Olivier Aumont ◽  
Laurent Bopp ◽  
...  
Keyword(s):  
Climate Change ◽  
Net Primary Production ◽  
Marine Ecosystem ◽  
Upper Ocean ◽  
Ecosystem Structure ◽  
Relative Role ◽  
Ecosystem Models ◽  
Export Production ◽  
Wide Range

Abstract. Accurate projections of marine particle export production (EP) are crucial for predicting the response of the marine carbon cycle to climate change, yet models show a wide range in both global EP and their responses to climate change. This is, in part, due to EP being the net result of a series of processes, starting with net primary production (NPP) in the sunlit upper ocean, followed by the formation of particulate organic matter and the subsequent sinking and remineralisation of these particles, with each of these processes responding differently to changes in environmental conditions. Here, we compare future projections in EP over the 21st century, generated by four marine ecosystem models under the high emission scenario Representative Concentration Pathways (RCP) 8.5 of the Intergovernmental Panel on Climate Change (IPCC), and determine the processes driving these changes. The models simulate small to modest decreases in global EP between −1 and −12 %. Models differ greatly with regard to the drivers causing these changes. Among them, the formation of particles is the most uncertain process with models not agreeing on either magnitude or the direction of change. The removal of the sinking particles by remineralisation is simulated to increase in the low and intermediate latitudes in three models, driven by either warming-induced increases in remineralisation or slower particle sinking, and show insignificant changes in the remaining model. Changes in ecosystem structure, particularly the relative role of diatoms matters as well, as diatoms produce larger and denser particles that sink faster and are partly protected from remineralisation. Also this controlling factor is afflicted with high uncertainties, particularly since the models differ already substantially with regard to both the initial (present-day) distribution of diatoms (between 11–94 % in the Southern Ocean) and the diatom contribution to particle formation (0.6–3.8 times higher than their contribution to biomass). As a consequence, changes in diatom concentration are a strong driver for EP changes in some models but of low significance in others. Observational and experimental constraints on ecosystem structure and how the fixed carbon is routed through the ecosystem to produce export production are urgently needed in order to improve current generation ecosystem models and their ability to project future changes.

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