Three new species of Gromia (Protista, Rhizaria) identified from the Romanian Black Sea shelf.

The protist genus Gromia was first described in 1835 by Dujardin and while gromiids are prominent in the marine environment, Gromia oviformis was, for a long time, the only valid species regularly recorded. To date, 16 species that are morphologically and/or genetically distinct have been described. While recent studies are documenting their diversity and their ecological importance, G. oviformis has been the sole gromiid species identified in the Black Sea, although unnamed Gromia species have also been recorded. We collected sediment samples from the Romanian continental shelf at varying depths (48 - 58 m) to study the morphological and genetic diversity of gromiids in this part of the Black Sea. Three new species, Gromia bugnae sp. nov., Gromia dianae sp. nov. and Gromia fabi sp. nov., were identified based on an integrative taxonomic approach, thus bringing the total described gromiid species to 19. Analysis of partial SSU rRNA gene sequences confirms that these are distinct species. Additionally, an undescribed species is represented by a sequence from the northern part of the Black Sea (Sevastopol, Kazachya Bay). The study provides further evidence of the diversity of gromiids in the Black Sea and underlines the importance of this little-known group in marginal seas.

Decline of unique Pontocaspian biodiversity in the Black Sea Basin: A review.

The unique aquatic Pontocaspian (PC) biota of the Black Sea Basin (BSB) is in decline. The lack of detailed knowledge on the status and trends of species, populations, and communities hampers a thorough risk assessment and precludes effective conservation. This paper reviews PC biodiversity trends in the BSB (Bulgaria, Romania, Moldova, Ukraine, and Russia) using endemic mollusks as a model group. We aim to assess changes in PC habitats, community structure, and species distribution over the past century and to identify direct anthropogenic threats. The presence/absence data of target mollusk species were assembled from literature, reports, and personal observations. Pontocaspian biodiversity trends in the northwestern BSB coastal regions were established by comparing 20th- and 21st-century occurrences. The direct drivers of habitat and biodiversity change were identified and documented. We found that a pronounced decline of PC species and communities is driven by (a) damming of rivers, (b) habitat modifications that disturbed previous natural salinity gradients and settings in the studied area, (c) pollution and eutrophication, (d) invasive alien species, and (e) climate change. Four out of the 10 studied regions, namely, the Danube Delta-Razim Lake system, Dniester Liman, Dnieper-Bug estuary, and Taganrog Bay-Don Delta, contain favorable ecological conditions for PC communities and still host threatened endemic PC mollusk species. Distribution data are incomplete, but the scale of deterioration of PC species and communities is evident from the assembled data, as are major direct threats. Pontocaspian biodiversity in the BSB is profoundly affected by human activities. Standardized observation and collection data as well as precise definition of PC biota and habitats are necessary for targeted conservation actions. This study will help to set the research and policy agenda required to improve data collection to accommodate effective conservation of the unique PC biota.

Social network analysis and the implications for Pontocaspian biodiversity conservation in Romania and Ukraine: A comparative study.

Romania and Ukraine share the Black Sea coastline, the Danube Delta and associated habitats, which harbor the endemic, aquatic Pontocaspian biota. Currently, this biota is diminishing both in numbers of species and their abundance because of human activities, and its future persistence strongly depends on the adequacy of conservation measures. Romania and Ukraine have a common responsibility to address the conservation of Pontocaspian biodiversity. The two countries, however have different socio-political and legal conservation frameworks, which may result in differences in the social network structure of stakeholder institutions with different implications for Pontocaspian biodiversity conservation. Here, we study the social network structure of stakeholder organizations involved in conservation of Pontocaspian biodiversity in Romania and the implications of network structure for conservation outcomes. Then we compare the findings from Romania to an earlier similar study from Ukraine. We apply a mix of qualitative and quantitative social network analysis methods to combine the content and context of the interactions with relational measures. We show that Pontocaspian biodiversity plays a minor and mostly incidental role in the inter-organizational interactions in Romania. Furthermore, there is room for improvement in the network structure through e.g. more involvement of governmental and nongovernmental organizations and increased motivation of central stakeholders to initiate conservation actions. Social variables, such as lack of funding, hierarchical, non-inclusive system of conservation governance and continuous institutional reforms in the public sector are consequential for the network relations and structure. Social network of stakeholders in Ukraine is more connected and central stakeholders utilize their favorable positions. However, neither in Ukraine is the Pontocaspian biodiversity a driver of organizational interactions. Consequently, both networks translate into sub-optimal conservation actions and the roads to optimal conservation are different. We end with sketching out conservation implications and recommendations for improved national and cross-border conservation efforts.