Romanian Black Sea Research Articles

Assessment of Heavy Metal Contamination of Seawater and Sediments Along the Romanian Black Sea Coast: Spatial Distribution and Environmental Implications

This study assesses the spatial distribution and contamination levels of some heavy metals (HMs), i.e., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb), in seawater and surface sediments along the Romanian Black Sea coast (RBSC). Sampling was conducted at 40 stations across 12 transects during May–June 2021, and the measured levels of HM concentrations were compared with Environmental Quality Standards (EQS), i.e., maximum allowable concentration (MAC) values, for seawater and effects range-low (ERL) thresholds for sediments. HM concentrations were measured using high-resolution continuum source atomic absorption spectrometry (HR-CS AAS). In seawater, the levels of Cd, Cu, and Pb concentrations exceeded the MAC values at three stations located in areas influenced by the Danube River or anthropogenic activities. In sediments, exceedances of ERL thresholds were found for Ni at 11 stations, for Cu at three stations, and for Pb at one station. HM contamination of sediment samples collected from these stations can be caused by both natural and anthropogenic sources, e.g., the Danube River, rock/soil weathering and erosion, agricultural runoff, port and construction activities, maritime and road transport, coastal tourism, petrochemical industry, wastewater discharges, offshore oil and gas extraction. Principal Component Analysis (PCA) provided valuable information about the relationships between relevant variables, including water depth and HM concentrations in seawater and sediments, and potential sources of contamination. The results highlight the influence of fluvial inputs and localized human activities on HM contamination. While the overall chemical status of Romanian Black Sea waters and sediments remains favorable, targeted management strategies are needed to address localized pollution hotspots and mitigate potential ecological risks. These findings provide valuable insights for environmental monitoring and sustainable coastal management.

First Report of Microplastic Ingestion and Bioaccumulation in Commercially Valuable European Anchovies (Engraulis encrasicolus, Linnaeus, 1758) from the Romanian Black Sea Coast

First Report of Microplastic Ingestion and Bioaccumulation in Commercially Valuable European Anchovies (Engraulis encrasicolus, Linnaeus, 1758) from the Romanian Black Sea Coast

A Long-Term Perspective of Seasonal Shifts in Nutrient Dynamics and Eutrophication in the Romanian Black Sea Coast

This study investigates the long-term seasonal shifts in nutrient dynamics and eutrophication processes in the Romanian Black Sea coastal waters using multi-decadal data (1960/1976/1980–2023). The findings highlight significant seasonal and interannual changes, revealing a progressive rise in seawater temperature, declining oxygen concentrations, and notable shifts in nutrient stoichiometry, particularly an increasing nitrogen–phosphorus (N:P) ratio. These changes are closely associated with increased occurrences of harmful algal blooms (Noctiluca scintillans), emphasizing the complex relationship between warming, nutrient and dissolved oxygen cycles, and biological activity. Seasonal patterns show that prolonged warmer periods, especially during autumn, exacerbate oxygen depletion and nutrient imbalances, with implications for marine life and food webs. The study underscores the importance of targeted nitrogen reduction strategies, including optimized fertilizer use, improved wastewater treatment, and the establishment of buffer zones to minimize land-based nutrient inputs. Regional cooperation and integrated coastal management aligned with the Marine Strategy Framework Directive are essential for mitigating eutrophication. The results provide critical insights into the impacts of climate change on the Black Sea ecosystems. This research contributes to global efforts under SDG 13 (Climate Action), SDG 14 (Life Below Water), and SDG 3 (Good Health and Well-being), addressing the key challenges to marine biodiversity, water quality, and ecosystem sustainability.

When “More” Is “Too Much”—A Study on Tourists’ Perception Regarding Beach Restoration in Mamaia on the Romanian Black Sea Coast

When “More” Is “Too Much”—A Study on Tourists’ Perception Regarding Beach Restoration in Mamaia on the Romanian Black Sea Coast

Assessing the Black Sea Mesozooplankton Community Following the Nova Kakhovka Dam Breach

In June 2023, following the breach of the Nova Kakhovka Dam during the Ukraine-Russia war, a comprehensive study was conducted along the Romanian Black Sea coast to assess water quality and mesozooplankton communities. Surface water analyses revealed significant gradients in nutrient levels and salinity, particularly from north to south, influenced by the influx of freshwater and nutrients from riverine sources and the dam breach. Flooding was found to significantly impact nutrient dynamics and species distributions, with increased concentrations of SiO4 and NO3 in flooded stations. A strong relationship was observed between environmental factors and biological assemblages, with silicates identified as a key driver. Biodiversity patterns varied across regions, with the Shannon–Wiener Index indicating lower zooplankton diversity in transitional waters, reflecting environmental stress. Statistical methods, including correlation analysis, multidimensional scaling, t-tests, and canonical analysis, were employed to investigate the links between mesozooplankton communities and environmental variables. These findings underscore disruptions in trophic dynamics and ecosystem balance, emphasizing the need for integrated environmental management strategies to mitigate further degradation and foster the ecological recovery of the Black Sea.

The Romanian coastal area and green transport infrastructure

The first part of the paper presents the local transport infrastructure conditions of the Romanian Coastal Area. The Coastal Area, from the geographical point of view is located on the East and South - East of the country, being part of South – East Development Region. It is aggregated mainly in two counties, Tulcea, where is found the intersection of Danube with Black Sea in Danube Delta and, Constanta where is the entire Romanian Black Sea shoreline. The first part also presents the steps that are already made by Romanian authorities to ensure the sustainability and reduce the pollution by increasing the green transport infrastructure. The second part of the paper presents the analysis of the transport system in the region together with the supporting data, and the challenges that puts pressure on our coastal area. Finaly, the aim is to come with solutions in order to increase sustainability, climate resilience, and to reduce the vulnerability on our coastal area with the purpose of multiplying and creating a good practice example for the entire community.

Physico-Chemical Methods Applied To Bioactive Compounds Determination From Ceramium Rubrum On The Romanian Coast Of The Black Sea

The red seaweed species Ceramium rubrum found in abundance along the Romanian Black Sea coast. Phylum Rhodophyta, Class Florideophycidae, Family Ceramiaceae, Genus Ceramium to which the species Ceramium rubrum belongs, is recognized due to two compounds: agar-agar and carrageenan which are widely used in the medical, pharmaceutical and food industry for their properties, agar-agar and carrageenan. The study aims to determine and quantify the active principles in the red seaweed Ceramium rubrum using IR and UV-VIS spectrometry and chromatographic methods. For IR spectrometry, dry algal powder and standard β-carotene used. For simultaneous evaluation of β-carotene, chlorophyll a and chlorophyll b, a chromatographic method (high performance liquid chromatography) applied. The antioxidant capacity analyzed by chemiluminescence method, showing remarkable results.

Extraction and Method Validation for Collagen Obtained from the Jellyfish Rhizostoma Pulmo Found on the Romanian Black Sea Coast

The biological qualities that collagen provides have been the basis for the continuous research and development of medicines, dematocosmetics, nutraceuticals, and food supplements. Fibrillar collagen is the most common type of protein. The interest in the study of jellyfish is justified by their increasing numbers and the biological structural and functional properties of the biocompounds they contain. Extraction, purification, characterization of collagen by known experimental methods, and determination of collagen yield for the jellyfish Rhizostoma pulmo species found in the Black Sea basin were extracted, purified, characterized, and determined. The validation of the method is also demonstrated by determining the collagen content by the hydroxyproline method. Validation is the confirmation, through examination and the provision of objective evidence, that particular requirements aimed at a defined and specific purpose are achieved.

An Integrative Approach to Assess and Map Zostera noltei Meadows Along the Romanian Black Sea Coast

Seagrass meadows, including those formed by Zostera noltei, play a crucial role in marine ecosystem health by providing habitat stability and coastal protection. In the Romanian Black Sea, Z. noltei meadows are critically endangered due to pressures from eutrophication, habitat loss, and climate change. This study presents a comprehensive baseline assessment of Z. noltei meadows near Mangalia, Romania, utilizing in situ field methods and UAV mapping conducted in the spring and summer of 2023. Seven meadow sites (Z1–Z7) were identified, with notable variability in density, shoot counts, and coverage across sites. Site Z1 exhibited the highest density (1223 shoots/m−2) and Z5 and Z7 the longest leaves (an average of 60 cm), reflecting possible environmental influences. Statistical analyses revealed significant inter-site differences in shoot density and leaf length, with density emerging as a primary differentiator. Ex situ analyses of epiphyte load indicated a median, balanced epiphyte load. This baseline dataset supported the selection of Z1 as a reference donor site for seagrass relocation activities along the Romanian coast in 2023. By providing critical insights into Z. noltei structure and health, this study supports future conservation efforts and evidence-based management of these vulnerable coastal habitats.

Underwater Noise Assessment in the Romanian Black Sea Waters

Underwater Noise Assessment in the Romanian Black Sea Waters

Recent Findings on the Pollution Levels in the Romanian Black Sea Ecosystem: Implications for Achieving Good Environmental Status (GES) Under the Marine Strategy Framework Directive (Directive 2008/56/EC)

This study provides a comprehensive evaluation of contamination levels in the Romanian Black Sea within the framework of the Marine Strategy Framework Directive (MSFD). Over the course of five oceanographic expeditions between 2020 and 2022, data were gathered from 70 stations in transitional, coastal, shelf, and offshore waters of the Black Sea. Analyses were conducted on water, sediment, and biota samples for key contaminants: heavy metals (HMs), polycyclic aromatic hydrocarbons (PAHs), and persistent organic pollutants (POPs) such as organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs). The assessment identified contamination hotspots near riverine inputs, urban runoff, harbor activities, and industrial discharges. Offshore waters also showed measurable pollutant levels, likely from diffuse sources and atmospheric deposition. The key findings reveal the widespread contamination of HMs, PAHs, and POPs across the Romanian Black Sea, with concentrations in certain areas exceeding acceptable environmental thresholds, highlighting ongoing challenges for regional pollution management. PAHs were prevalent in both nearshore and offshore regions, while OCPs and PCBs were detected across various matrices, with significant concentrations observed in water and biota samples. The study emphasizes the importance of integrated assessments within the MSFD framework, suggesting that future evaluations should complement the “one out-all out” (OOAO) approach with multi-metric tools, to enhance the robustness of pollution status reporting. Despite improvements in some areas, contamination remains a critical challenge, requiring strengthened regulations, improved waste management, and increased regional cooperation to mitigate the ongoing risks to marine ecosystems. The findings provide valuable data for the upcoming national MSFD assessment cycle (2018–2023) and highlight the need for sustained monitoring and coordinated efforts to ensure long-term marine sustainability.

Current levels of inorganic and organic pollutants in Romanian marine waters: Implications for ecosystem health

Human activities continue to impact the Romanian Black Sea, with implications for the marine ecosystem. This study presents new data (2023) on the spatial distribution of heavy metals, persistent organic pollutants, and nutrients in Romanian Black Sea waters. Our findings reveal the influence of various pollution sources, including the Danube River, municipal and industrial discharges, and maritime activities. Nutrient loads, primarily from the Danube and diffuse sources, exert pressure on the pelagic habitat. While there has been some improvement in nutrient conditions, the potential for increased eutrophication due to climate change remains a concern. Understanding the spatial distribution of pollutants and identifying their sources is crucial for developing effective management strategies to protect the marine environment.

Morphological characteristics of the species Gaidropsarus Mediterraneus (Linnaeus, 1758) population from the Romanian Black Sea coast in the year 2023

The aim of this study is to provide an overview of the Gaidropsarus mediterraneus (Linnaeus, 1758) species growth pattern from the Romanian Black Sea Coast, in the year 2023. This has been accomplished by studying the length-weight relationship, an important parameter, which helps to know the growth pattern of fish populations, Fulton’s condition factor (kc) (useful index for monitoring feeding intensity) from 180 shore rockling individuals caught by pots. Average lengths and weights were 24.4 ± 2.6 cm and 101.46 ± 38.11 g, respectively, the minimum and maximum values were 18.3 and 33.8 cm, 36 and 319 g in weight. The value of exponent b in the equation is 3.197, indicating that the increasing weight is allometrically positive and mean value of the Fulton was 0.68 ± 0.08, with the minimum and maximum values of 0.47 to 0.90. The obtained results can have useful effects on the stock management of this fish species.

Ulva species from the Romanian Black Sea Coast – between green blooms and nature’s contribution to people

Ulva species have a worldwide distribution and remarkable ability to develop under various conditions, being considered an important natural resource that is under-exploited along the Romanian Black Sea coast. These green algae, involved in green tides observed worldwide, have also a remarkable potential as prolific sources of bioactive compounds with potential health benefits and a wide range of applications in food, feed, pharmaceutical, nutraceutical, cosmetic, or biofuel industries. The study aims to analyze the quantitative variability of Ulva spp. during 2019 - 2023, in order to highlight the areas with algal agglomerations. These are also areas where potential algal deposits can develop during summer season. This fresh biomass can be selectively collected and valorized, thus supporting the circular economy. The sampling method was the classic one (square method/20x20 cm) from 14 stations along Pescarie towards Vama Veche, at depths between 0 to 3 m deep. Among all Ulva spp., Ulva rigida and Ulva intestinalis quantitatively distinguished during the study period, being also the main components of algal deposits. The highest mean wet biomasses were recorded in the southern part, as follows: U. rigida – a maximum value of 2200 g/m2 at 2 Mai; U. intestinalis – max. value of 700 g/m2 at Eforie South. Furthermore, a review of species’ main bioactive compounds, emphasizing their potential health benefits, will also be provided.

Current status of zoobenthic fauna associated with macroalgae fields from the southern Romanian Black Sea coast

The European environmental policies related to marine water management require a periodic environmental status assessment. The Marine Strategy Framework Directive 2008/56/EC clearly specifies that assessment must take into consideration benthic habitat types, including their associated biological communities. The aim of this study is to present the results of the ecological analysis of the zoobenthic communities associated with benthic habitats with macrophytic substrate and to provide new data regarding the qualitative and quantitative structure of macroinvertebrates that populate these habitats type. The broad habitats type Infralittoral rock and biogenic reef and Infralittoral sands were investigated. The analyzed data covers the summer season, 2023 based on the processing of 13 samples collected from Navodari to 2 Mai – Vama Veche, on depths ranging between 1m to 3 m. A total of 80 macrozoobenthic species were found in all macrophytic assemblages, the Polychaeta, Crustacean and Gastropod were the dominant groups, especially Perinereis cultrifera, Platynereis dumerilii, Ampithoe ramondi, Stenothoe monoculoides, Rissoa splendida, Tricolia pullus registering a large number of individuals. For data interpretation a synecological analysis was performed allowing the identification of the species with the most significant contribution in the ecosystem in terms of function, energy exchanges with the environment, the characteristic species of a biotope or those that have an accidental presence in the studied area.

Evolution of the beach artificial nourishments in the Tomis North sector, a short term analysis (2013-2024)

The Romanian coastline is part of the western coast of the Black Sea, extending for about 245 km, morphologically divided into two units: the northern unit, from Musura Bay to Cape Midia, with deltaic and lagoon origin, and the southern unit, from Cape Midia to Vama Veche, characterised by well-developed cliffs and wide beaches. This last coastal sector includes both accumulating coastlines (beaches) and anthropogenic features (ports and breakwaters). Constanta, the largest and most important city in Dobrogea, claims a rich history and a variety of tourist attractions, with its beaches stretching some 6 km along the coast from Tomis Marina to the entrance of Mamaia Resort. This study analyses the recent changes observed at a popular tourist beach known as Reyna Beach, located near Mamaia Resort, following the nourishment works carried out in the framework of the "Protection and Rehabilitation of the Southern Part of the Romanian Black Sea Coast" project. The project involved extensive hydrogeographic works, including the rehabilitation of piers, the construction of submerged breakwaters and beach nourishment. This paper aims to analyse the evolution of the coastal area from a geographical perspective, including geological and geomorphological characteristics, using various data sources such as satellite images, field measurements and previous maps associated to grounding studies.

Updated state of small scale fisheries on the Romanian Black Sea area

Romanian small-scale fisheries are practiced along the Black Sea coast in five fishing ports (Sulina, Cape Midia, Tomis, Constanta and Mangalia) and 18 other small fishing stations, located between Sulina - Vama Veche, at depths ranging between 2 - 20 m and sometimes up to 50 m, when practicing specialized turbot fisheries. Of significant importance is fishing with divers for the Rapana venosa, the species with the greatest impact on the landed catches. In the coastal area, between Vama Veche and Sulina, which also represents an important area for the reproduction, feeding and rearing of some important fish species, the small-scale fishing is practiced with fixed and active gear, throughout the year, mainly using the following types of fishing gears: pound nets, gillnets, longlines, beach seines, cages/traps, handlines and from 2013 with beam trawl. Catch and fishery productivity vary yearly, depending on environmental conditions, fishing effort, status of main commercial species, and human factors. During the analyzed period (2019 - 2023), catches in shallow waters were between 7149 and 3127 tons, which has an increasing trend compared to the previous period (2012 – 2017).

Growth patterns and age determination of Piked Dogfish from Romanian Black Sea waters: Insights from spines analysis

Understanding the growth patterns and the age composition of Squalus acanthias (piked dogfish) populations, from Romanian marine area, helps to elaborate sustainable fisheries management practices because changes in population parameters could indicate shifts in prey availability, habitat quality issues, or fishing pressure. In recent years, the official catches on the Romanian coast, of this economically valuable species in the entire Black Sea basin, have remained below one ton. Regarding the growth patterns, a slight increase in the average length value was observed, from 107,85 cm in 2022 to 116,88 cm in 2023. For age determination the method of analyzing the dorsal spines was used, considered the most appropriate. Thus, in 2022 mature specimens (19 years old) predominated, and in 2023, younger specimens (14 years old), but completely mature from a reproductive point of view, predominated. Analyzing age structure over time is important for predicting future population trends and implementing conservation measures as needed.

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.