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.
Aim
The introduction of aquatic non‐indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections ...since 1965 to inform conservation policy and management.
Location
Global.
Methods
We assembled an extensive dataset of first records of detection of ANS (1965–2015) across 49 aquatic ecosystems, including the (a) year of first collection, (b) population status and (c) potential pathway(s) of introduction. Data were analysed at global and regional levels to assess patterns of detection rate, richness and transport pathways.
Results
An annual mean of 43 (±16 SD) primary detections of ANS occurred—one new detection every 8.4 days for 50 years. The global rate of detections was relatively stable during 1965–1995, but increased rapidly after this time, peaking at roughly 66 primary detections per year during 2005–2010 and then declining marginally. Detection rates were variable within and across regions through time. Arthropods, molluscs and fishes were the most frequently reported ANS. Most ANS were likely introduced as stowaways in ships’ ballast water or biofouling, although direct evidence is typically absent.
Main conclusions
This synthesis highlights the magnitude of recent ANS detections, yet almost certainly represents an underestimate as many ANS go unreported due to limited search effort and diminishing taxonomic expertise. Temporal rates of detection are also confounded by reporting lags, likely contributing to the lower detection rate observed in recent years. There is a critical need to implement standardized, repeated methods across regions and taxa to improve the quality of global‐scale comparisons and sustain core measures over longer time‐scales. It will be fundamental to fill in knowledge gaps given that invasion data representing broad regions of the world's oceans are not yet readily available and to maintain knowledge pipelines for adaptive management.
The SE Baltic region harbors a diverse assemblage of alien amphipods of Ponto-Caspian origin. The composition of this fauna was shaped by three invasion waves: (1) pre-twentieth century dispersals ...via watershed-connecting canals, (2) deliberate introductions in the 1960s, and (3) last decade dispersals via shipping and existing canals. Given this complex history, we test whether genetic diversity (mitochondrial COI and nuclear OPS) differs between the native and invaded ranges and between the deliberately introduced species and the ones that dispersed on their own. We find that in the native range the two species groups exhibited similar COI diversity, while OPS diversity was higher in the deliberately introduced species. In the invaded range, COI diversity significantly decreased in all species, but more so in the self-dispersed group. No change in OPS diversity was detected among ranges. Mitochondrial diversity was more structured geographically in the native range, and the dominant invasive haplotypes were detected in the native populations of all but one species, further highlighting the utility of this marker in tracing invasion sources. Our comparative approach provides important insight into the inter-range genetic diversity of Ponto-Caspian invaders, highlighting the role of introduction mode.
Social networks, defined as sets of relationships between stakeholder organizations, are important determinants of constructive actions for biodiversity conservation. Such actions are achieved ...through cooperation between various stakeholders, exchange of information, and joint planning and implementation. We used a mix of qualitative and quantitative social network analysis methods to investigate the interorganizational network of stakeholders in Ukraine, and the implications of network properties for the conservation of Pontocaspian biodiversity. Pontocaspian biota contains unique and endemic fauna, which are threatened by anthropogenic impacts; this makes effective conservation measures an urgent priority. We identified a well-connected, centralized network in Ukraine. However, the strong network has not resulted in effective conservation of Pontocaspian biodiversity. Suboptimal conservation action stems from the subordinate role of Pontocaspian species in the interorganizational interactions, likely due to lack of knowledge regarding Pontocaspian taxa. Social variables, such as funding scarcity and legal constraints, further limit the effectiveness of biodiversity conservation actions. We conclude that the current landscape of stakeholders in Ukraine is well placed to rapidly improve conservation actions if they are supplied with improved information and recognition of conservation needs of Pontocaspian taxa, combined with improved financial and legal conditions.
Europe has a long history of human pressure on freshwater ecosystems. As pressure continues to grow and new threats emerge, there is an urgent need for conservation of freshwater biodiversity and its ...ecosystem services. However, whilst some taxonomic groups, mainly vertebrates, have received a disproportionate amount of attention and funds, other groups remain largely off the public and scientific radar. Freshwater mussels (Bivalvia, Unionida) are an alarming example of this conservation bias and here we point out six conceptual areas that need immediate and long‐term attention: knowledge, threats, socioeconomics, conservation, governance and education. The proposed roadmap aims to advance research, policy and education by identifying the most pressing priorities for the short‐ and long‐term conservation of freshwater mussels across Europe.
ABSTRACT
Here, we investigate the shell shape variation of some closely related freshwater species of the bivalve genus Corbicula using descriptive (qualitative), geometric morphometric and ...traditional conchometric approaches. The combination of these different approaches allows for an effective discrimination between the species C. fluminalis, C. fluminea and C. leana, as well as an unidentified Corbicula sp. The roundness of the shell hinge is an important diagnostic feature, as are shell sculpture (ribs), symmetry of the apertural margin, and both position and extension of the umbo. We also identify possible hybrids between C. fluminalis and C. leana, with these showing features intermediate to those of the parent species. We examine variability of shell features of C. leana in selected areas in Europe and compare these results with material from the native range of Japan and Korea. For C. leana, we identify two geographic morphotypes from the native area; within Europe, there is a high morphological diversity of this species with several new forms arising, most probably as a result of hybridization.
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.
Distribution data of unique, endemic Pontocaspian (PC) biodiversity of the Black Sea Basin is incomplete, but the scale of deterioration of PC species and communities is evident from the assembled data, as are major direct threats. This review will help to set the research and policy agenda required to improve data collection to accommodate effective conservation of the unique PC biota.
New information on the occurrence of two alien decapod crustaceans,
Macrobrachium nipponense
and
Procambarus virginalis
, was summarized for Ukraine. The invasive potential of both species was ...estimated in the context of local environmental and socio-economic issues. Their history as non-native species is marked by the early use of alien decapods as a natural resource by local residents. Both intentional and unintentional introductions occurred for
M. nipponense
, while the ornamental trade was an important source of non-native
P. virginalis
. New records of
M. nipponense
and
P. virginalis
from open freshwater habitats in the Odesa and Kharkiv provinces suggest continuing expansion of these decapods. We conducted a molecular phylogenetic analysis of
COI
sequences, which confirmed morphological identifications of invasive
M. nipponense
. This reinforces the presumed pathway of this species, including its pathway from China to south-western Ukraine.
Procambarus fallax
was found to be paraphyletic in relation to
P. virginalis
, which was probably caused by analyzing only one mitochondrial gene, which could be impacted by the recent emergence of the latter species.
De nouvelles informations sur la présence de deux crustacés décapodes exotiques,
Macrobrachium nipponense
et
Procambarus virginalis
, ont été compilées pour l'Ukraine. Le potentiel d'invasion des deux espÉces a été estimé dans le contexte des problèmes environnementaux et socio-économiques locaux. Leur histoire en tant qu'espèces non indigènes est marquée par l'utilisation précoce des décapodes exotiques comme ressource naturelle par les résidents locaux. Des introductions intentionnelles et non intentionnelles ont eu lieu pour
M. nipponense
, tandis qu'un commerce ornemental a été une source importante de
P. virginalis
non indigène. De nouveaux signalements de
M. nipponense
et de
P. virginalis
dans des habitats d'eau douce ouverts dans les provinces d'Odesa et de Kharkiv suggèrent une expansion continue de ces décapodes. Nous avons effectué une analyse phylogénétique moléculaire des séquences COI, qui a confirmé les identifications morphologiques de
M. nipponense
envahissante. Cela renforce la voie présumée de cette espèce, y compris sa trajectoire de la Chine vers le sud-ouest de l'Ukraine. On a constaté que
Procambarus fallax
était paraphylétique par rapport à
P. virginalis
, ce qui est probablement dû à l'analyse d'un seul gène mitochondrial, qui pourrait être affecté par l'émergence récente de cette dernière espèce.
EDITOR'S NOTE: This is 1 of 12 papers prepared by participants attending the workshop “Risk Assessment in European River Basins–State of the Art and Future Challenges” held in Liepzig, Germany on ...12–14 November 2007. The meeting was organized within the framework of the European Commission's Coordination Action RISKBASE program. The objective of RISKBASE is to review and synthesize the outcome of European Commission FP4–FP6 projects, and other major initiatives, related to integrated risk assessment–based management of the water/sediment/soil environment at the river basin scale. Over the past century, the potential for aquatic species to expand their ranges in Europe has been enhanced both as a result of the construction of new canals and because of increased international trade. A complex network of inland waterways now connects some previously isolated catchments in southern (Caspian, Azov, Black, Mediterranean seas) and northern (Baltic, North, Wadden, White seas) Europe, and these waterways act as corridors for nonnative species invasions. We have developed a conceptual risk assessment model for invasive alien species introductions via European inland waterways, with specific protocols that focus on the development of environmental indicators within the socioeconomic context of the driving forces–pressures–state–impact–response framework. The risk assessment protocols and water quality indicators on alien species were tested for selected ecosystems within 3 main European invasion corridors, and these can be recommended for application as part of the Common Implementation Strategy of the European Commission Water Framework Directive, which aims to provide a holistic risk-based management of European river basins. The conceptual structure of the online Risk Assessment Toolkit for aquatic invasive alien species is provided and includes 3 main interlinked components: online risk assessment protocols, an early warning system, and an information transmitter for risk communication to end users.
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