Exposure to a variety of anthropogenic stressors has prompted the creation of a growing number of marine protected areas (MPAs). Unfortunately, long-term changes in both the sources of stress and the extent or operation of the MPAs have also occurred, at a pace that is often faster than the research trying to understand the consequences of those changes. This study addresses this challenge by focusing on two MPAs located in the southern Romanian Black Sea, namely the Cape Tuzla and the Mangalia Sulfur springs. Using 95 seafloor samples collected over a 7-year period, we explored distinct benthic habitats and their associated communities in a depth gradient common to both MPAs. We described benthic communities, their density, biomass, and diversity and subsequently used them as indicators of the health of the seafloor. Specifically, we used the M-AMBI*(n) index to assess the ecological status of the benthic habitats found in both MPAs. Our results identified seven distinct habitats across infralittoral and circalittoral areas and described species composition and diversity levels, reaching up to a grand total of 119 benthic taxa. These communities were often dominated by polychaetes and crustaceans in terms of density and by mollusks in terms of biomass. Several mollusks represent key ecosystem engineer species creating or modifying their local habitat conditions. Our results revealed that two thirds of the sampling stations could be characterized as having a good ecological status (GES), and were therefore dominated by species normally considered as either sensitive or indifferent to organic pollution. Meanwhile, the other third of the stations was labeled as non-GES, was dominated by opportunistic species and represent a concern for the coastline system. This study calls for further research to carefully describe the valuable coastal habitats under the frame of MPAs, and to assess the effects of specific pollutants and the response of organisms that seem most affected by these stressors.

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.

This study is based on data concerning the macrobenthos fauna from Modiolus phaseolinus biocoenosis, obtained in 2006 - 2007 from 56 stations distributed on the North-Western continental shelf of the Black Sea. A total of 95 taxa belonging to 19 phyla were found. The average density of macrobenthic community was about 5249.11 indv.m-2 while their average biomass was 257.76 g.m-2. At all stations, the Polychaeta contributed most to the multi-species biocoenosis structure. All results point to a slight recovery of the Modiolus phaseolinus biocoenosis. When compared to long-term studies on macrobenthos, it is evident that the results represent only a momentary state in the succession of the open-sea communities, which have been affected by past changes, and will be subject to future changes in accordance with the variable environment, affected by climate.

Fisheries Restricted Areas (FRAs), as area-based fisheries management tools, can be effective in providing protection for fisheries and biodiversity, in addition to traditional Marine Protected Areas (MPAs), and are already in effect in waters above 1,000 m of the Mediterranean and the Black Seas. Whereas in the North-Western part of the Black Sea all fishing activities are concentrated in the shallow area (at depths of maximum 90 m), where species and habitats of conservation interest are present, this restriction is completely irrelevant. In this context, given that a FRA can also be established nationally (nFRA), the main objective of this research was pre-identifying suitable area(s) at the Romanian coast and providing the scientific substantiation for such an endeavor. In addition to being a traditional fishing ground for small-scale local fishermen, the study perimeter, which includes the Northern Romanian coast (part of the Marine Zone of the Danube Delta Biosphere Reserve), was chosen for various reasons. First, because of the uniqueness of the habitats found here, it serves as a vital forage area for fish species that are valuable both from a conservation and economic standpoint. Additionally, during the past ten years, beam trawl fishing for the gastropod Rapana venosa (Valenciennes, 1846) has affected the area, potentially causing harm to benthic habitats. A variety of data sources were integrated as part of the research strategy, including the composition and spatial distribution of macrozoobenthos, an inventory of the local fish fauna conducted through scientific fishing (both for commercial fish and species of conservation interest), fish stomach content analysis (by dissection or gastric lavage), and records of fishing effort and catch. The identified Sf. Gheorghe - Sahalin nFRA, covering 272.76 km² between the 40 m and 50 isobaths, proved to be appropriate according to both ecological and fisheries criteria, and, after public consultation, was established by law, thus becoming the first national Fisheries Restricted Area in the Black Sea, to the benefit of both nature conservation, by spillover effects to adjacent areas, and the livelihood of local coastal communities.

This survey reports the spatial distribution of gastropods belonging to Caenogastropoda, Architaenioglossa, Littorinimorpha, Cycloneritida and Hygrophila orders, and malacostracans from Amphipoda and Mysida orders in the lower sector of the Danube River, Romania, using DNA barcoding based on the cytochrome C oxidase I (COI) gene sequence. Sampling was performed for eight locations of Danube Delta branches and Bechet area during three consecutive years (2019–2021). Molecular identification of sixteen gastropods and twelve crustacean individuals was confirmed to the species level, providing the first molecular identification of gastropods from the Lower Danube sector. Phylogenetic analysis showed that species of gastropods and crustaceans clustered in monophyletic groups. Among gastropods, Microcolpia daudebartii acicularis, Viviparus viviparus, Bithynia tentaculata, Physa fontinalis, Ampullaceana lagotis and Planorbarius corneus were identified in Chilia and Sulina branches; and the Bechet area was populated by Holandriana holandrii, Theodoxus transversalis and Gyraulus parvus. The amphipods and mysids were present along the three main Danube branches. The calculated density of these species revealed an abundant community of crustacean Chelicorophium robustum on Sulina branch, and Dikerogammarus haemobaphes and D. villosus in extended areas of the Danube Delta. The presence of these invertebrates along Danube River was reported in relation to the sediment type and water depth.

On the basis of the analysis of 27 samples collected by diving in 9 stations along the South Sector of the Romanian Black Sea coast, the authors present the qualitative and quantitative state of the benthic community of the hard bottom mussels in the shallow waters. The study, carried out in mid and upper-infralittoral in August 2001, reveals the occurrence of 68 species and 11 supraspecific taxa, with an average density of 750,000 indvs.m-2 and a biomass of 16,500 g.m-2: Numerical dominants are represented by worms (~ 460,000 indvs.m-2) and crustaceans (~ 270,000 indvs.m-2), and the weight dominants by mollusks – Mytilus galloprovincialis over 95% (~ 16,300 g.m-2) and crustaceans (~ 137 g.m-2). The general ecological state of the hard bottom mussel benthic community of the Romanian Black Sea coast in August 2001 can be considered satisfactory in comparison with the 1980s.