Vegetation Characteristics and Recent Successional Trends of Sand Dune Habitats at the Bulgarian Black Sea Coast

Coastal dunes are valuable and vulnerable habitats that require scientific exploration and understanding of their natural processes; therefore, the aims of this study were to determine the current vegetation characteristics of dune habitats along the Bulgarian Coast in terms of species richness and cover of typical psammophytes and different non-psammophytic plant groups, and to analyze how they respond to certain environmental drivers. Data were collected from 12 dune systems. The research was focused on embryonic, white and grey dunes. The field work was conducted throughout July and August 2017. The vegetation was sampled at 154 phytosociological plots (5 m × 5 m). To understand how the vegetation responds to different drivers, we tested the correlation of defined species group richness and cover in relation to (1) the soil pH and EC values, (2) the distance from inland to the sea and (3) the range of different categories of land cover in the surrounding area. In order to track temporal vegetation changes, we compared the cover of defined species groups between 2003 and 2017. We registered a total number of 269 vascular plants, 12 bryophytes and 5 lichens. The strongest presence in all dune types, both in species richness and cover, was the group of grass- and shrubland plants. Weeds and ruderal plants had significant coverage in grey dunes, while the richness and cover of forest and alien plants were negligible among the studied dune habitats. The comparison of data between 2003 and 2017 revealed a substantial decline in the cover of psammophytes. We observed a clear pattern regarding the share of species richness of psammophytes and non-psammophytes among different locations. We detected that grey dunes were the most affected by the penetration of non-psammophytes.

Additional records and new species of Hydraena Kugelann, 1794 (Insecta: Coleoptera: Hydraenidae) from Balabac and Palawan, Philippines

Three new species of the genus Hydraena Kugelann, 1794 of the Philippine Island of Palawan are described in detail, namely H. angelitofelipepunoi sp. n., H. buschietanni sp. n., and H. perpusilla sp. n., along with faunistic records of further species of the genus from previously unexplored areas of Balabac and Palawan. The genital characters of the new species are illustrated by digital line drawings. Photographs of their habitus and type localities are provided. The habitat conditions of their collection sites are assessed and implications of the usefulness of Hydraena species as monitoring organisms for the conservation of vulnerable habitats are briefly discussed. An updated checklist of the Hydraena of Greater Palawan is provided which now comprises 15 described species, of which 13 are endemic to this intra-Philippine island complex.

Coastal Wetland Shoreline Change Monitoring: A Comparison of Shorelines from High-Resolution WorldView Satellite Imagery, Aerial Imagery, and Field Surveys

Shoreline change analysis is an important environmental monitoring tool for evaluating coastal exposure to erosion hazards, particularly for vulnerable habitats such as coastal wetlands where habitat loss is problematic world-wide. The increasing availability of high-resolution satellite imagery and emerging developments in analysis techniques support the implementation of these data into shoreline monitoring. Geospatial shoreline data created from a semi-automated methodology using WorldView (WV) satellite data between 2013 and 2020 were compared to contemporaneous field-surveyed Global Position System (GPS) data. WV-derived shorelines were found to have a mean difference of 2 ± 0.08 m of GPS data, but accuracy decreased at high-wave energy shorelines that were unvegetated, bordered by sandy beach or semi-submergent sand bars. Shoreline change rates calculated from WV imagery were comparable to those calculated from GPS surveys and geospatial data derived from aerial remote sensing but tended to overestimate shoreline erosion at highly erosive locations (greater than 2 m yr−1). High-resolution satellite imagery can increase the spatial scale-range of shoreline change monitoring, provide rapid response to estimate impacts of coastal erosion, and reduce cost of labor-intensive practices.

Invasion success on European coastal dunes

Many invasive plants are threatening the already highly vulnerable habitats of coastal dunes in Europe. Setting priority target species to control is mandatory for an effective planning of invasion management strategies at European level. This can be possible after identifying the species that currently have greater invasion success, in consideration of their ecological traits and origin. We quantified the three main components of invasion success for the extra-European alien plants found on European coastal dunes: local abundance, regional distribution and niche breadth, and related them to their life forms and origins. We found that life form was a better predictor of invasion success. In particular, geophytes and therophytes were the species with the greatest invasion success. Quite surprisingly, alien plants from Africa appeared as the group with slightly higher mean invasion success although this result was no statistically significant. We also highlighted the species deserving special attention. Among these, Xanthium orientale, Erigeron canadensis and Oenothera gr. biennis showed the widest levels of niche breadth and regional distribution, and had overall the greatest invasion success, but other species also had high levels in one of the three components of invasion success.

Another mystery snail in the Adirondacks: DNA barcoding reveals the first record of Sinotaia cf. quadrata (Caenogastropoda: Viviparidae) from North America

ABSTRACTAlien molluscs pose a serious threat to global freshwater diversity and have been implicated in many ecosystem-altering invasion events over the past few decades. Biomonitoring surveys are therefore a key tool for ensuring biosecurity in diversity hotspots and vulnerable habitats. In this study, we use DNA barcoding to provide the first record of the viviparid, Sinotaia cf. quadrata from North America. Reciprocal monophyly and low genetic divergence (uncorrected p-distance: 0.004) with a Bellamya quadrata individual from the type region (China) provides strong support for this identification. The species was recovered as part of a routine biomonitoring survey of the Adirondack region of northern New York. Only three adults were recovered (no populations or juveniles) indicating that the discovery represents a very recent arrival. Considering the proximity of the sampling site from the massive St. Lawrence River, it is likely that S. cf. quadrata was introduced into the St. Lawrence, probably via the aquarium plant trade, and was able to spread into smaller river system in northern New York and possibly other border states. This record represents the fourth alien viviparid, the third of which is of Asian origin, that have made its way to New York waters. Future biomonitoring efforts for the upcoming summer period will involve targeted searches for S. cf. quadrata to determine the extent of its spread in the region.

An overview of Persian Gulf environmental pollutions

Aquatic environments are among the most vulnerable habitats that affect all Organisms. The Persian Gulf is home to numerous plant and animal species, and the biological safety is at risk due to its numerous human activities. Traffic of numerous oil and commercial vessels in the area, waste water, desalination, proximity of numerous industrial, refinery and petrochemical units to shores and rivers, oil rigs, fishing, and tourism activities are potential hazards to the environment and should lead to severe chemicals and physicals pollution into the Persian Gulf ecosystem. All this while the Persian Gulf is highly vulnerable due to various natural in the reason of such as low water circulation due to isolation, high evaporation, and low water depth. In this article, previous studies on the status of pollutants in the Persian Gulf have been reviewed. Much of the research on Persian Gulf pollution has focused on hydrocarbons and heavy metals. However, according to recent research, the amounts of these pollutants have been lower than the allowed levels. Also, further research into the impacts of plastics and microplastics on the Persian Gulf ecosystem should be undertaken.

Impairment of microbial and meiofaunal ecosystem functions linked to algal forest loss

Habitat loss is jeopardizing marine biodiversity. In the Mediterranean Sea, the algal forests of Cystoseira spp. form one of the most complex, productive and vulnerable shallow-water habitats. These forests are rapidly regressing with negative impact on the associated biodiversity, and potential consequences in terms of ecosystem functioning. Here, by comparing healthy Cystoseira forests and barren grounds (i.e., habitats where the macroalgal forests disappeared), we assessed the effects of habitat loss on meiofaunal and nematode biodiversity, and on some ecosystem functions (here measured in terms of prokaryotic and meiofaunal biomass). Overall, our results suggest that the loss of Cystoseira forests and the consequent barren formation is associated with the loss of meiofaunal higher taxa and a decrease of nematode biodiversity, leading to the collapse of the microbial and meiofaunal variables of ecosystem functions. We conclude that, given the very limited resilience of these ecosystems, active restoration of these vulnerable habitats is needed, in order to recover their biodiversity, ecosystem functions and associated services.

Low diversity or poorly explored? Mesophotic molluscs highlight undersampling in the Eastern Mediterranean

Mesophotic assemblages are the next frontier of marine exploration in the Mediterranean Sea. Located below recreational scuba diving depths, they are difficult to access but host a diverse array of habitats structured by large invertebrate species. The Eastern Mediterranean has been much less explored than the western part of the basin and its mesophotic habitats are virtually unknown. We here describe two mesophotic (77–92 m depth) molluscan assemblages at a rocky reef and on a soft substrate off northern Israel. We record 172 species, of which 43 (25%) are first records for Israel and increase its overall marine molluscan diversity by 7%. Only five of these species have been reported in recent surveys of the nearby Lebanon, suggesting that our results are robust at a broader scale than our study area and that the reported west-to-east declining diversity gradient in the Mediterranean needs a reappraisal based on proper sampling of the eastern basin. We found only four (2%) non-indigenous species, represented by seven (0.5%) specimens. These results suggest that pristine native assemblages still thrive at this depth in Israel, in contrast to the shallow subtidal heavily affected by global warming and biological invasions, calling for strong conservation actions for these valuable but vulnerable habitats.