Responsible aquaculture, the farming of aquatic organisms, is a sustainable strategic sector for land and coastal communities. It significantly contributes to food security and enhancement of economic development; it provides employment opportunities and often contributes to the ecological services provided by the environment. According to the Food and Agriculture Organization of the United Nations (FAO), the contribution of aquaculture to the global food security is widely demonstrated by an astounding industry growth of 7.5% per year since 1970. In 2018, aquaculture reached the all-time highest production of 114.5 million tonnes in live weight with a total farm gate sale value of USD 263.6 billion. This makes aquaculture a key player within the Blue Growth concept and a strong contributor to some of its key Sustainable Development Goals (SDG). This is particularly true in geographical areas where dependence of local economies on fishery products is high, and yet access to sustainable landings is hampered by ecological barriers. One such area is represented by the Black Sea basin. Whilst the Black Sea annual capture fishery production has varied considerably since 1990 and its current landings are significant, growing attention is currently given to boost aquaculture development along the Black Sea bordering countries, with marine aquaculture being considered as an important contributor to the total fisheries production. Nonetheless, aquaculture development in this region is not homogenous and its development has, so far, been limited by environmental, economic, social, and more generally governance issues. This paper, for the first time, attempts to provide a comprehensive fresh outlook of the aquaculture sector in the Black Sea, stressing the importance of regional cooperation as an essential pillar to support the sustainable development of the industry. The paper addresses aquaculture in the Black Sea from different perspectives: it outlines the key characteristics of the Black Sea environment; it discusses the most common farmed aquatic species and the potential for new ones; it frames the national approaches to aquaculture development, sharing information about success stories, while shedding light on the main challenges and priorities ahead. This collective endeavour will represent a helpful contribution to Black Sea riparian countries to answer the many questions they have, and expectations they hold from the aquaculture sector.

Worldwide, states are gazetting new Marine Protected Areas (MPAs) to meet the international commitment of protecting 30% of the seas by 2030. Yet, protection benefits only come into effect when an MPA is implemented with activated regulations and actively managed through continuous monitoring and adaptive management. To assess if actively managed MPAs are the rule or the exception, we used the Mediterranean and Black Seas as a case study, and retrieved information on monitoring activities for 878 designated MPAs in ten European Union (EU) countries. We searched for scientific and grey literature that provides information on the following aspects of MPA assessment and monitoring: ecological (e.g., biomass of commercially exploited fish), social (e.g., perceptions of fishers in an MPA), economic (e.g., revenue of fishers) and governance (e.g., type of governance scheme). We also queried MPA authorities on their past and current monitoring activities using a web-based survey through which we collected 123 responses. Combining the literature review and survey results, we found that approximately 16% of the MPA designations (N = 878) have baseline and/or monitoring studies. Most monitoring programs evaluated MPAs based solely on biological/ecological variables and fewer included social, economic and/or governance variables, failing to capture and assess the social-ecological dimension of marine conservation. To increase the capacity of MPAs to design and implement effective social-ecological monitoring programs, we recommend strategies revolving around three pillars: funding, collaboration, and technology. Following the actionable recommendations presented herein, MPA authorities and EU Member States could improve the low level of MPA monitoring to more effectively reach the 30% protection target delivering benefits for biodiversity conservation.

The widespread use of Tebuconazole-based fungicides in phytosanitary treatments on a wide range of crops, on the one hand, and the lack of official reports on the amount of fungicide residues in nearby water basins, on the other hand, may lead to uncontrolled and hazardous contamination of water sources used by the resident population, and to serious effects on the environment and public health. Our study explores the acute toxicological risk of this fungicide on various organisms, from bacteria and yeast to fish, using a battery of tests (standardized Toxkit microbiotests and acute semi-static tests). By investigating the interaction between Tebuconazole and bacteria and yeast organisms, we observed that Gram-negative bacteria displayed a strong tolerance for Tebuconazole, while Gram-positive bacteria and yeasts proved to be very sensitive. The fish experiment was conducted on Chelon auratus juveniles exposed to five concentrations of the fungicide Tebustar EW (Tebuconazole, 250 g/L as active substance). After 96 h of exposure, the LC₅₀ for C. auratus was 1.13 mg/L. In the case of the Toxkit microbiotests’ application, the following results were recorded: Spirodela polyrhiza EC₅₀ = 2.204 mg/L (after 72 h exposure), Thamnocephalus platyurus EC₅₀ = 0.115 mg/L (after 24 h), and Daphnia magna EC₅₀ = 2.37 mg/L (after 24–48 h). With the exception of bacteria and yeast, the same response pattern was observed for all non-target species tested; the response range expressed by concentrations causing growth inhibition or mortality was small, ranging between very close values that are quite low, thereby demonstrating the high toxicity of Tebuconazole-based fungicides to the environment.

The North-Western Black Sea shelf is extremely vulnerable to disturbances of its habitats and ecosystems. In the past 10 years, this area has become targeted by beam trawl fisheries for the invasive gastropod Rapana venosa (Valenciennes, 1846), with a potentially destructive impact on the area’s soft bottoms. Not many studies have been performed in the region, and most investigations have focused on gear selectivity and by-catch rates. In this context, our novel research aimed, on the one hand, to assess and quantify the actual impact of beam trawling and, on the other hand, to propose effective spatial/temporal management measures for a sustainable zonation of the North-Western Black Sea shelf (marine zone of the Danube Delta Biosphere Reserve). The methodology used integrated beam trawl catch dynamics information, VMS data, geophysical investigations, and macrozoobenthos sampling. Our findings show that beam trawling activities can cause changes in the benthic habitat structure (lower number of taxa, lower values of ecological indicators, and an overall non-GES status). Further in-depth investigations are needed to underpin the ecosystem-based management of this marine protected area (MPA), aiming to allow the recovery of the affected benthic habitats, by alternating defined areas undergoing fishing with biological recovery polygons.

The extension of the Natura 2000 European ecological network to the Romanian marine territory (1 site according to the Birds Directive requirements and eight sites according to the Habitats Directive requirements, one also being a natural reserve and one part of the Danube Delta Biosphere Reserve) might cause conflicts between the Romanian marine fishery and these sites. In order to minimize such conflicts, the evaluation of the interaction between fishery and the preservation objectives of the Natura 2000 sites is compulsory and extremely important. The assessment of the environmental impact is a key tool of the EU environmental legislation, which is used in evaluating the effect of human activities on the ecosystem. In addition, the involvement of all interested stakeholders in the development of the fishery on the Romanian littoral and in environmental protection will be the key to success in finding viable co-management solutions in the Natura 2000 sites. The present paper aims to examine how the fisheries interact with the marine environment on the Romanian coast in the network of marine protected areas.

The aim of this paper was to investigate the biological and ethological response of golden grey mullet Chelon auratus (Risso, 1810) fries collected from Romanian Black Sea shallow waters to different salinities and temperatures, in order to document the optimal conditions for controlled rearing. The species’ potential for aquaculture is enhanced by its eurihalyne and eurithermal adaptability, allowing it to grow in a variety of ecosystems, including the Romanian Black Sea area, with its highly variable salinity and temperature specificities. Three experimental set-ups were designed: a salinity tolerance test, with 5 salinity regimes (0.3‰, 5‰, 10‰, 15‰ and 20‰), a temperature tolerance experiment, involving both temperature decrease (down to 8°C) and increase (up to 34°C), and an extreme salinity test, reaching a maximum value of 95‰. The aggregated results obtained from the three experiments indicated that golden grey mullet fries can indeed tolerate a wide range of temperatures (8°C - 36°C) and salinities (5‰-70‰), with the optimal range between 10‰ and 30‰ salinity, at temperatures of 10°C - 25°C. The practical purpose of this investigation was supporting the diversification of local mariculture species, as mullets can be excellent candidates for the enhancement of aquaculture in the area.