Romanian Black Research Articles

The Problem of Power Variations in Wind Turbines Operating under Variable Wind Speeds over Time and the Need for Wind Energy Storage Systems

One of the most important and efficient sources of green electricity is catching air currents through wind turbine technology. Wind power plants are located in areas where the energy potential of the wind is high but it varies. The time variation of the wind generates fluctuations in the power produced by the wind farms that is injected into the grid. This elevates, depending on the intensity, problems of network stability and the need for balancing energy, thus raising both technical and cost issues. The present paper analyzes the behavior of a wind turbine (WT) over time in varying wind speed conditions, highlighting that without automation algorithms, a WT is far from the operation at the maximum power point (MPP). However, even when it is brought to operate at MPP, there are still significant variations in the power injected into the network. These power variations can be compensated if the wind system has energy storage facilities for the captured wind. All of these assumptions are analyzed using improved mathematical models and processed in simulations, with experimental data used as input from a wind turbine with an installed power of 2.5 [MW] in operation on the Romanian Black Sea coastal area. Consequently, the paper demonstrates that during an operation in the optimal area, from an energy perspective, the wind turbine’s maximum power point requires a storage system for the captured wind energy.

Recent Trends in Air Pollution in the Most Important City of The Romanian Black Sea Coast

Air pollution is one of the greatest environmental issues of contemporary society, affecting virtually all major cities worldwide, including those in Romania. Consequently, evaluating the dynamics of pollution conditions in urban environments is essential for designing control measures and adaptation strategies to this environmental disruption. This paper aims to analyze the recent dynamics of pollution and air quality in Constanta, the largest city on the Romanian coastline and one of the most important cities along the entire Black Sea coast. The investigations were based on the official concentrations of major atmospheric pollutants recorded at air quality monitoring stations located within or near Constanta. The dynamics of pollutant concentrations were explored at annual and seasonal levels, and the results showed a mixed picture of changes in the atmospheric pollutant concentrations, in recent years. Essentially, the findings highlighted both increases and decreases in air pollution conditions, emphasizing the need for constant air quality monitoring and controlling throughout Constanta city.

Heavy Metal Concentrations in Wild Mussels Mytilus galloprovincialis (Lamarck, 1819) during 2001–2023 and Potential Risks for Consumers: A Study on the Romanian Black Sea Coast

Heavy Metal Concentrations in Wild Mussels Mytilus galloprovincialis (Lamarck, 1819) during 2001–2023 and Potential Risks for Consumers: A Study on the Romanian Black Sea Coast

Methodology for prioritizing marine environmental pressures under various management scenarios in the Black Sea

This study aims to develop a methodology for identifying predominant pressures on the marine ecosystem, emphasizing the significance of examining these pressures and the necessity for management scenarios. The research focuses on how the Black Sea ecosystem responds to the combined effects of human pressures, climate change, and policies. An in-depth analysis was conducted on environmental pressures affecting the Romanian Black Sea, highlighting dominant pressures such as physical habitat loss, hydrocarbon introduction, and non-indigenous species invasion. The research employs a novel methodological approach to assess the implications of these pressures under different Shared Socioeconomic Pathways (SSPs): SSP1 “Taking the Green Road”, SSP2 “Middle of the Road”, and SSP5 “Taking the Highway”. The findings reveal a complex interplay between economic development and environmental conservation, with each pathway presenting distinct outcomes for marine ecosystems. Recent developments, including beach rehabilitation, maritime transport, and oil and gas exploitation, have overshadowed traditional pressures such as nutrient introduction and fishing. The study identifies the increasing vulnerability of critical habitats to anthropogenic pressures, with the rehabilitation of these ecosystems remaining challenging even under reduced pressures. The results underscore the need for adaptive management strategies to enhance the Black Sea ecosystem’s sustainability and resilience. The study’s insights are important for developing management strategies that address ongoing environmental challenges. This research provides knowledge for policymakers and stakeholders involved in marine management and conservation efforts in the Black Sea region, emphasizing the importance of adaptive strategies to mitigate the adverse effects of human activities and climate change on marine ecosystems.

BIOCHEMICAL CHARACTERIZATION AND EXPLOITATION POSSIBILITIES OF Gongolaria Barbata (Stackhouse) Kuntze 1891 FROM THE ROMANIAN BLACK SEA COAST

Black Sea macroalgae are a marine resource with many benefits. Gongolaria barbata (Stackhouse) Kuntze 1891 (formerly known as Cystoseira barbata (Stackhouse) C. Agardh, 1820) is a brown macroalga with an essential role in biodiversity and in the marine ecosystem functioning, considered an ecologically valuable species at the Romanian Black Sea coast. Samples were collected during 2002 and 2023 years (August-September) from 6 stations of the Romanian Black Sea coast in order to characterize biochemically and highlight the presence of some biologically active compounds with therapeutic, pharmaceutical and cosmetic interest. Biochemical composition (dry matter, moisture, ash, organic matter, crude proteins, crude lipids, carbohydrates, chlorophyll a, chlorophyll b, carotenoids) and dietary fiber (CF, ADF, NDF, NDF, NDS, ADL) were evaluated in this study. The obtained results indicate some differences between the two years and these are influenced by the environmental conditions and physiological state of macroalgae. Although present on the Romanian coast, Gongolaria barbata has not been intensively studied in terms of its valorization potential, but it has recently attracted attention due to its biochemical properties that lead to some possibilities of use for economic purposes. The existence of valuable biochemical compounds in the composition of this brown macroalga qualifies it in the marine resources category of interest with biotechnological applications.

FOOD AVAILABILITY ON INFLUENCE MUSSEL Mytilus galloprovincialis (Lamarck, 1819) ON PHYSIOLOGICAL AND BIOCHEMICAL STATUS

Phytoplankton, as the primary food source for suspension-feeding bivalves, can significantly impact the growth and survival of bivalves. To investigate the influence of food availability on the condition index and biochemical composition of mussels Mytilus galloprovincialis from the Romanian Black Sea coast, phytoplankton and mussels samples were collected from four sites between November 2017 and November 2018. The phytoplankton quality and quantity varied across locations and seasons. The ports had the highest diversity and abundance of phytoplankton, while the area with low trophic conditions had the lowest. The most dominant phytoplankton groups observed were diatoms and dinoflagellates. The condition index values were higher in sites with greater food availability, reaching the peak in spring. The lipid and carbohydrate content peaked in spring when the food availability was high. The protein content was higher in winter and autumn. Condition index was positively correlated with phytoplankton abundance and biomass (p 0.05). Several significant correlations were found between the biological parameters of mussels, such as proteins, lipids, carbohydrates, tissue dry weight, moisture, ash free dry weight, and ash. In conclusion, the results indicated that higher food availability and increasing seawater temperatures led to greater condition index and reserve accumulation, primarily in the form of proteins, carbohydrates, and lipids, providing mussels with enough energy to withstand stressful conditions.

Long term succession of engineering species Gongolaria barbata (Stackhouse) Kuntze (Fucales: Ochrophyta) along the Romanian Black Sea coast

Background and purpose: Cystoseira sensu lato are of great interest due to their primary role in maintaining high biodiversity and the functioning of rocky habitats, and as provider of crucial ecosystem services. Conspicuous historical declines have been reported in many regions, Romanian Black Sea coast included. Gongolaria barbata (Stackhouse) Kuntze (Fucales: Ochrophyta) is the only remaining representative of Cystoseira s. l. along the Romanian coast and currently the most important habitat-forming species, with extended to patchy canopies in the southern rocky coasts. To better understand the status of such ecological important species, we analyse and compare the succession of Gongolaria infralittoral populations during reference (60s), decline (70s) and more recent period (2009 – 2022), based on an extensive literature review (historical quantitative data) and recent information from annual monitoring program. Material and methods: Quadrats (20 × 20 cm) were used for sampling both in the past and present, with a total number of 144 samples collected between 2009 – 2022. Both historical and recent data were statistically analysed using non – parametric tests due to the absence in normality and homogeneity of data sets. Results: Following sea ice from 1972 and violent storms as the main drivers of local Gongolaria decline, out of the thirteen known development areas from the reference period, nowadays only five are left. However, recent wet biomass and density values are appropriate to those of the reference period (1962 – 1971) and much higher compared to the maximum decline period (1972 – 1979). Conclusions: G. barbata has been in a fragile balance along the Romanian coast in the last decade, highly sensitive in front of increasingly anthropogenic activities.

Reducing greenhouse gas emissions in Romanian agriculture using renewable energy sources

This paper aims to demonstrate the feasibility, regarding environmental and economical point of view, of a local tomato farm powered by an offshore wind farm for Romanian Black Sea coast, where there are no such projects implemented and just one is foreseen so far. In this regard, both the agricultural farm and the offshore wind farm were dimensioned and using a new methodology proposed in the year 2023 by the World Bank, an environmental analysis of the project was made with estimating the positive effects that occur in the GHG emissions at the implementation of this project. The relationship between energy inputs and farm yields is analysed for two cycles of tomato crops and a comparative evaluation is conducted to emphasise the favourable influence that the implementation of the proposed solution would exert on the carbon footprint of Romania's agriculture sector. The two scenarios considered are Scenario 1 - S1 with tomato farm in the Schitu area (in greenhouses powered by an offshore wind farm, Cycle 1 and in open field, Cycle 2) and Scenario 2 - S2 when the tomatoes are imported from proximate regions. For both cycles, the energy ratio and energy productivity values were calculated, obtaining 0.11 and 0.13 for cycle C1, and 0.67 and 0.84 for cycle C2, respectively. The benefits of the proposed solution presented in S1 are represented by a) enhancing agricultural production by exploiting a renewable energy source with a yearly production of 45.07 GWh; b) reducing the transport distance of tomatoes by 324,057 km; c) promoting the local economy by employing an average of 124 people; d) improving the carbon footprint of Romania's agricultural sector with a reduction of CO2e per year of 43.13%.

Spatial Cumulative Assessment of Impact Risk-Implementing Ecosystem-Based Management for Enhanced Sustainability and Biodiversity in the Black Sea

Marine ecosystems are becoming increasingly vulnerable to cumulative anthropogenic effects and pressures. Therefore, various methodological approaches and tools have been designed to apply cumulative impact appraisal schemes and better assess the dynamics and interactions among pressures affecting marine ecosystems. This study aims to apply the Spatial Cumulative Assessment of Impact Risk for Management (SCAIRM) tool for the Black Sea coastal waters considering human activities, pressures, and effects on different ecosystem components coupled with one management scenario development for actual and new emerging sectors. According to the SCAIRM, the primary pressure on the marine ecosystem was identified as introducing or spreading non-indigenous species from shipping. Additionally, when considering cumulative impact, activities related to coastal defense and flood protection, particularly beach nourishment works, were found to have the highest impact. This is due to the cumulative scores associated with the physical loss from permanent alteration or removal of seabed substrates, and temporary or reversible physical disturbances to the seabed. The scenario development indicated that after shipping, oil and gas exploitation is anticipated to become the second-highest risk sector for additional impact in the Romanian Black Sea. Additionally, the increased military activities related to the war in Ukraine present escalating risks that must be considered in EBM strategies. The results assess the possible effects of human activities and the associated pressures to direct management toward achieving sustainability, biodiversity protection, and the marine ecosystem’s integrity.

From Isolated Valves to a Potential Marine Living Resource: History, Documented Distribution and Sustainable Population Enhancement Possibilities of the Smooth Scallop (Flexopecten glaber) on the Romanian Coast

Until recently, the smooth scallop Flexopecten glaber (Linnaeus, 1758) was considered absent from Romanian Black Sea waters, as only isolated valves were documented on beaches of the southern coast. Yet, in 2020, the first living specimens were collected by dredging at 25 m depth in Mangalia. Moreover, in the past three years, a considerable number of live individuals were also retrieved from beam-trawling operations targeting the gastropod Rapana venosa (Valenciennes, 1846) along the Romanian coast, indicating that there is a stable population here. This remarkable expansion of F. glaber in Romanian waters may be explained as a consequence of the Black Sea’s recovery from eutrophication, reduced predatory pressure from the declining population of R. venosa and changing climate conditions. Our research aimed at using all this novel information to document for the first time the occurrence and distribution of this bivalve on the Romanian coast, also considering perspectives for the development of a new type of shellfish mariculture, avoiding any pressure on the natural stock. In total, 386 F. glaber individuals were sampled during 2020–2023, at depths between 22.5 and 33.3 m. The abundance and biomass per station oscillated between 5 and 319 specimens and 51.5 and 7377 g, respectively. A subsample of 122 specimens was preserved and analyzed in the laboratory, revealing an average shell length of 53.54 mm (±4.13 SD) and an average shell height of 49.54 mm (±3.64 SD). The smooth scallop has both ecological and economic value, which makes it a viable candidate for sustainable aquaculture by collecting spat from the most abundant areas and subsequently placing “seedlings” in the appropriate polygons for stock recovery. Ultimately, commercial exploitation from aquaculture installations can be considered, provided a permanent healthy F. glaber population is established on the Romanian coast.

Qualitative Model of the Causal Interactions between Phytoplankton, Zooplankton, and Environmental Factors in the Romanian Black Sea

In order to analyze how environmental factors affect planktonic organisms along the Romanian Black Sea coast, this study created semi-quantitative models of the causal relationships between phytoplankton, zooplankton, and physicochemical parameters by utilizing user-friendly modeling tools. Eleven years of time-series data (March–September 2008–2018) were used to investigate the relationships between phytoplankton, zooplankton, and environmental factors (such as temperature, salinity, and nutrients). Variables such as marine reporting units and phytoplankton species and classes were used to identify developmental patterns, utilizing the Mental Modeler platform to consider interactions between the physicochemical parameters and phytoplankton, phytoplankton and zooplankton, and zooplankton and physicochemical parameters. Although the increase in the overall number of elements and linkages was uncertain in waters with variable salinity compared to marine ones, the semi-quantitative models created for the three marine reporting units along the Romanian Black Sea coast were comparable in terms of complexity. Across the typical and examined types of phytoplankton proliferation (normal, abundant, and blooms), the number of components and connections in the case of phytoplankton blooms substantially decreased as species- and growth-promoting variables increased.

Modeling Dynamic Processes in the Black Sea Pelagic Habitat—Causal Connections between Abiotic and Biotic Factors in Two Climate Change Scenarios

The paper contributes to the Sustainable Development Goals (SDGs) targeting Life Below Water by introducing user-friendly modeling approaches. It delves into the impact of abiotic factors on the first two trophic levels within the marine ecosystem, both naturally and due to human influence. Specifically, the study examines the connections between environmental parameters (e.g., temperature, salinity, nutrients) and plankton along the Romanian Black Sea coast during the warm season over a decade. The research develops models to forecast zooplankton proliferation using machine learning (ML) algorithms and gathered data. Water temperature significantly affects copepods and “other groups” of zooplankton densities during the warm season. Conversely, no discernible impact is observed on dinoflagellate Noctiluca scintillans blooms. Salinity fluctuations notably influence typical phytoplankton proliferation, with phosphate concentrations primarily driving widespread blooms. The study explores two scenarios for forecasting zooplankton growth: Business as Usual, predicting modest increases in temperature, salinity, and constant nutrient levels, and the Mild scenario, projecting substantial temperature and salinity increases alongside significant nutrient decrease by 2042. The findings underscore high densities of Noctiluca scintillans under both scenarios, particularly pronounced in the second scenario, surpassing the first by around 70%. These findings, indicative of a eutrophic ecosystem, underscore the potential implications of altered abiotic factors on ecosystem health, aligning with SDGs focused on Life Below Water.

Trends in the Evolution of the Average Length of Stay in Tourist Destinations on the Romanian Black Sea Coast

Trends in the Evolution of the Average Length of Stay in Tourist Destinations on the Romanian Black Sea Coast

The Variability of the Beach Morphology and the Evolution of the Shoreline in the Strongly Anthropized Sector of Eforie North, the Romanian Coast of the Black Sea

The Eforie Nord sector (between the southern pier of Agigea - Constanta port and the tourist port of Belona), is characterized, from a geomorphological point of view by the presence of high cliffs and narrow beaches. In the mentioned sector, a series of coastal protection works were carried out in several stages, respectively: between 1956 and 1960, 6 groins were placed to etend the perimeter beach; with the epansion of Constanța port, new coastal protection measures were imposed (1981-1986), determined by the erosion processes, made concrete by the eecution of permeable submerged longitudinal dikes in addition to the transversal ones. On long term, the measurements of shore morphological parameters highlighted that the southern sector of the Romanian Black Sea coast is subject to an erosion process, due to the action of both natural and anthropogenic factors, each generating effects with different intensity, depending on local conditions. Within the project “Protection and Rehabilitation of the Southern Part of the Romanian Black Sea Coast, Phase 1” in 2014-2015 period, in the mentioned sector, etended hydrographical works were carried out, including the rehabilitation of dikes, the construction of submerged dikes and beach nourishment. The monitoring of the shore behavior at regular intervals (annual/seasonal) which is essential for an adequate management of the coastal area, highlights both cyclical/seasonal morphological changes (rapid erosion as a result of storms in the cold season and the reconstruction of the beach during summer) and progressive/multiannual changes. The monitoring of morpho dynamic changes at shore level includes the positioning of the shoreline and beach profiles in 6 locations using GPS equipment (geodetic and GIS class). The resulting spatial data were processed and included in the SANDS management system that allows comparative analysis at different time scales. The maps representations were made in the ArcGIS 10.8 system. The data analysis revealed seasonal changes of the shore morphology, both in the longitudinal profile (shoreline) and transversally (beach profiles).

Valorization of Mussel Waste from the Romanian Black Sea Coast

In this study the shells and byssus of Mytilus galloprovincialis, the mussels from the Romanian Black Sea coast were studied through biotechnological techniques, to determine if they can be highly economically valorized. The shells were processed in order to obtain calcium carbonate (CaCO3) and subsequently calcium chloride (CaCl2), natural compounds with multiple practical applications in the pharmaceutical industry, medicine, agriculture, animal husbandry, environment, etc. Calcium carbonate was obtained from mussel shells with a yield of 95.31%, and calcium chloride was obtained with a yield of 73.80% from CaCO3, percentages that support the efficiency of the biotechnological processes for obtaining these products. The byssus collected from M. galloprovincialis was processed using a pepsin-aided etraction method, which allowed obtaining collagen with a yield of 27,56%. Mussel byssus is a waste and may provide an alternative to other types of eisting collagen from animal sources with different applications in pharmaceutical industry, tissue engineering, medical field, food industry, cosmetics.

Romanian Black Sea Mesozooplankton’s Seasonal Dynamics and Distribution during 2013-2020

The analysis of the mesozooplankton community from the Romanian Black Sea waters revealed variations both from quantitative and qualitative point of view. A decrease in the number of identified taa according to the season was observed, with a maimum of 25 taa in the warm season and a minimum of 15 taa in the cold season. The nonfodder component represented by Noctiluca scintillans recorded the highest density and biomass values in the warm season, in the cold season being less represented, fact highlighted by Simper analysis. The mesozooplanktonic fodder component showed variations of density and biomass, copepods and the meroplanktonic component representing the bulk of the community in the warm season. In the warm season, the group of Cladocera’s recorded high density and biomass values, unlike in the cold season where they were very poorly represented. Other groups were better represented also in the warm season, showing a decrease in terms of abundance and biomass in the cold season.

Diversity and dynamics of tintinnids communities from Romanian Black Sea, in 2021

Tintinnids are tiny ciliates from microzooplankton that are very important due to their implication in the microbial food web and for the fact that in the last two decades a considerable number of non-indigenous species have entered and acclimatized in the Black Sea basin. The paper presents the species diversity and dynamic of microzooplanktonic tintinnids’ abundance as a result of two cruises carried out in May-June and August-September 2021, along the Romanian Black Sea coast. We identified 23 tintinnid species in total, with a higher diversity in the surface layer compared to those of depth. The species Eutintinnus sp. and Salpingella decurtata were found eclusively in the 10 m layer. Tintinnopsis cylindrica represented 74% of the mean biomass of tintinnid’s community from May-June, the best quantitative representation recorded in the Romanian coast's northern sector. Amphorellopsis acuta represented 91% of the mean biomass of tintinnid’s community in August-September. The biotic component was also correlated with temperature and salinity to give more information regarding spatial and temporal variations from one area to the other. The findings contribute to the knowledge of microzooplankton communities in the Romanian Black Sea region. The data on species composition, abundance distribution, and environmental correlations enhance our understanding of the ecological dynamics and potential ecological implications of tintinnid communities. This study brings valuable information to the understanding of the microzooplankton component in the Black Sea ecosystem.

Tannic Acid Content in the Cultured Diatom Skeletonema costatum (Greville) Cleve 1873, Isolated from the Romanian Black Sea Waters

Skeletonema costatum is a dominant species in the spring phytoplankton composition of the Romanian Black Sea coastal waters. The species was isolated during a spring bloom and maintained in laboratory conditions for the past 10 years. The biomass was obtained by culturing the species in growth medium for diatoms under continuous light and shaking for four days. The biomass was harvested by vacuum filtration and lyophilized. The tannic acid content was determined by the HPLC method in the methanolic etract of S. costatum biomass. The tannic acid content was 0.46% (4.6 mg tannic acid/g biomass). Also, the chromatogram showed the presence of other separate, but unidentified organic compounds, which may contribute to its therapeutic potential. Our results justify further research to highlight S. costatum antioidant and antimicrobial activity.

Association between foot skin temperature (FST) and locomotion scoring (LS) in dairy cattle

The health status of the hoof in dairy cattle is crucial for their overall well-being and productivity. Hoof diseases and lesions can lead to lameness, decreased milk production, and economic losses for dairy farmers. Traditional methods of assessing hoof health involve manual inspection and trimming, which can be time-consuming and subjective. This research article explores the potential use of a phone-connected infrared camera as a non-invasive and objective tool for assessing the health status of the hoof in dairy cattle, by investigating the association between foot skin temperature (FST) and locomotion scoring (LS) in a group of Romanian Black Spotted dairy cows. LS was carried out using the mobile app developed by the Wisconsin University (Locomotion Scorer). The thermograms were collected during afternoon milking and processed using the FLIR software. Overall, 73.9% of the cows were scored as non-lame, while 13.04% presented signs of foot lesions. The highest temperature observed in the interdigital area, in the lame group, by thermography, was T°=36.5°C. In conclusion, monitoring hoof health status in dairy cattle is essential for ensuring their well-being and productivity. The use of an infrared thermal camera for the assessment of foot surface temperature has shown promise as a noninvasive tool for evaluating hoof health.

Dynamics of Zooplankton along the Romanian Black Sea Coastline: Temporal Variation, Community Structure, and Environmental Drivers

Between 2013 and 2020, a total of 27 distinct zooplankton taxa, encompassing both holoplanktonic and meroplanktonic organisms spanning different classes and orders, were successfully identified along the Romanian Black Sea coastline. The seasonal dispersion patterns of these zooplankton taxa revealed a notable augmentation in species identification during the warmer periods, contrasting with reduced zooplankton diversity during the colder seasons. This phenomenon was underscored by the outcomes of SIMPER analysis, which highlighted that copepods, meroplankton, and cladocerans predominantly contributed to the community structure during warmer seasons. In contrast, during colder seasons, cladocerans were scarcely represented, and the density levels of copepods and meroplankton were diminished. From a quantitative perspective, the dinoflagellate Noctiluca scintillans, exhibited its highest density and biomass during the warm season, with a relatively lower representation during colder periods. The variation in the abundance of zooplankton was closely linked to changes in salinity and temperature, culminating in noticeable fluctuations, which were particularly evident during the cold season. During this period, the values of zooplankton abundance were notably lower compared to those observed in the warmer season. The comprehension of zooplankton dynamics stands as a critical facet for assessing biodiversity, monitoring ecosystem well-being, and guiding conservation endeavours.