Citizens and scientists work together to monitor marine alien macrophytes

The introduction of non-indigenous species (NIS) is an ongoing phenomenon which has been pointed out as a major threat to biodiversity at different levels. NIS may in time become invasive (Invasive Alien Species “IAS”) and may cause biodiversity loss and ecosystem service changes. The Mediterranean Sea is an important hotspot for marine NIS (ca. 1,000 such species recorded to date. To reduce the risk of future IAS introduction and to better understand their invasive potential and spread dynamics, monitoring and surveillance plans are required. The creation of permanent alarm systems and public awareness campaigns are crucial for reducing the risk of IAS introduction. Since intensive monitoring programs could be very expensive, citizen science, involving citizens (e.g. tourists, fishermen, divers) in the collection of data, could be a useful tool for providing data on IAS, that would otherwise be impossible to collect because of limitations on time and resources. Citizen science is having an increasing success worldwide. Citizen science projects has rapidly and enormously increased in recent years, also thanks to the wide availability of mobile technologies and internet access that enable an easy and cheap way to communicate, share and interchange data. The value of citizen science has been widely recognized. Of course, in order to be used for scientific purposes and management decisions, the collected data need appropriate quality assurance measures such as validation and verification by taxonomic experts. We report on the experience of two citizen science projects: the Project “Caulerpa cylindracea – Egadi Islands” and the Project “Invasive Algae”, included within the “Seawatchers” platform

A contribution to the phylogeography of Pinctada imbricata radiata (Leach, 1814) (Bivalvia: Pteriidae) from the Eastern Mediterranean Sea by means of the mitochondrial COI marker

Pinctada imbricata radiata (Leach, 1814) was the first Lessepsian bivalve reported in the Mediterranean Sea where it is progressively expanding westward. Its native range includes the Indian Ocean and western Atlantic. The present study provides the first insight into the species’ phylogeographic structure, by analysing sequences of a 385-bp region of the mitochondrial gene coding for the subunit I of the cytochrome c oxydase (COI). Sixty-four individuals collected at seven Mediterranean localities were sequenced; in addition, eight COI sequences of individuals from the species’ native range (Persian Gulf) were retrieved from GenBank. Overall, we detected 10 haplotypes. Samples from both the native range and invaded localities were characterised by low levels of haplotype and nucleotide diversity (total h = 0.351, total π = 0.0013). Significant genetic divergence was found between Persian Gulf and Mediterranean Sea samples, whereas very shallow genetic structuring was observed within the Mediterranean study area. Moreover, no pattern of isolation by distance was detected in the Mediterranean. From a historical demography perspective, our results on Mediterranean samples were consistent with a very recent, or even ongoing, demographic expansion. Range expansion of exotic thermophilic species in this area is a widely observed phenomenon that many authors have related to global warming

Oil spill risk assessment on the Maltese coastal areas

A significant percentage of the global oil transport goes through the Mediterranean sea. Most of the maritime traffic carrying oil and other dangerous liquid substances travels across the Malta Channel. The risk of marine spillages within the stretch of sea between Malta and Sicily is very high and beaching on the Maltese shores can cause irreversible environmental damage at the detriment of important economic resources. The aim of this work is to determine the probability and volume percentage of oil that would reach the coast in case of an accident in the proximity of the Maltese Islands. Various spill scenarios are considered to get a realistic estimate as much as possible.peer-reviewe

Species identification of the psammophilous tenebrionid beetles Phaleria acuminata Juster, 1852 and Phaleria bimaculata (Linnaeus, 1767) from central Mediterranean beaches: geometric morphometrics and molecular insights from species to population level

Dominating global arid environments, from desert to coastal dunes, most Tenebrionidae are highly specific in their habitat preferences and display limited dispersal potential, thus exhibiting a remarkable degree of regional genetic and morphological differentiation. The tenebrionid genus Phaleria is speciose and widely distributed, with P. acuminata and P. bimaculata having a wide Mediterranean distribution, with numerous morphological differentiations at population level, often described as different taxa of doubtful taxonomical significance. In order to investigate the variability of the central Mediterranean populations of P. bimaculata and P. acuminata and to compare the results obtained with different identification techniques, these species were sampled on sandy beaches in Sicily (southern Italy) and on circum-Sicilian and Maltese islands. Collected samples were studied through the application of geometric morphometrics and the sequencing of a fragment of the mitochondrial COII gene. Geometric morphometrics and molecular analyses gave congruent results, allowing a sound separation of the two species. At the population level, the two species showed different patterns. P. acuminata showed a remarkable morphological and molecular homogeneity throughout the sampled area. Conversely, two well-characterized subclades were detected within P. bimaculata, and within the two lineages, a low-to-absent inter-populations differentiation was observed, in spite of the physical isolation of the sampled sandy beaches and of their geographical distance. These two P. bimaculata lineages, hereby named ‘‘Tyrrhenian sub-clade’’ and ‘‘Southern sub-clade,’’ might be compatible with the hypothesis of subspecific status already proposed for the populations from the Aeolian archipelago (as P. bimaculata marcuzzii Aliquo`)

The first confirmed record of the Atlantic blue crab Callinectes sapidus Rathbun, 1896 (Decapoda, Brachyura) from Maltese waters

The invasive portunid species Callinectes sapidus is hereby recorded for the first time from Maltese waters, thus updating the known distribution of this decapod of Atlantic origin within the Mediterranean. Potential introduction pathways of the species to Maltese waters are discussed

Is the endemic Maltese Top-shell Gibbula nivosa extinct?

The trochid gastropod Gibbula nivosa, endemic to the Maltese Islands, has recently only been found in two Maltese bays, where it occurred on seagrass leaves and under stones at depths of 1-4m. Intensive sampling of Cymodocea nodosa and Posidonia oceanica meadows, sediment and pebbles at depths of 2-12m, carried out in 2000 and 2002, resulted only in empty shells but no live animals, suggesting that the species is extinct from these localities where previously good populations were found. However, the occurrence of fresh shells from other Maltese sites suggests that small undiscovered populations may exist. G.nivosa is considered to be ’critically endangered’.peer-reviewe

Bridging the knowledge gap on the distribution and typology of vermetid bioconstructions along the Maltese coastline: an updated assessment

In the Maltese Islands, insufficient attention has been paid to vermetid reefs, endemic Mediterranean bioconstructions widely distributed along the southern part of the basin. As a result, this is a largely-overlooked coastal ecosystem despite the multitude of ecosystem services it provides. The perennial urban development in the Maltese Islands calls for the adoption of urgent action to protect coastal habitats, in particular bioconstructions that increase biodiversity and contribute to mitigating the effects of climate change. The objective of our study was to extensively document the presence and typology of the vermetid reef ecosystems along the coast of Malta and Gozo, assessing the occurrence of putative anthropogenic threats on the same ecosystem. Quantitative measurements were additionally taken to morphologically characterize the recorded bioconstructions. Furthermore, we tested the human pressure effect on the density of vermetid individuals and associated biodiversity. “True” trottoirs were only documented along the south-east coast of Malta, where unfortunately land reclamation projects are expected to be implemented. Although no direct relation between a number of assessed human activities and the density of vermetid individuals was reported in the current study, we suggest the conduction of further studies to investigate the influence of specific disturbances on the conservation status of this ecosystem. This study expands the existing knowledge on the status of vermetid reefs in the Maltese Islands and calls for management and conservation actions to preserve this bioconstruction

Bridging knowledge gaps towards 2030 : the use of foresight for the strategic management of a sustainable blue economy

There is need to better understand the trends and future challenges influencing the marine and coastal environments and identify the opportunities to develop innovative sustainability-oriented solutions to address these. Alongside mainstream decision support tools used in environmental management and conservation sciences, foresight techniques provide comprehensive and well-rounded information and knowledge about likely developments in the long-term future. This study uses a horizon scanning exercise to explore emerging signals and trends of future developments and innovation for the sustainable development of the blue economy looking towards 2030. It derives a series of global developments, challenges and opportunities relating to the blue economy from a review of high-level international reports and studies. Through a workshop conducted with 29 scientists and researchers based in maritime universities in six countries in Europe, the study identifies and prioritizes emerging signals and trends considered of high impact for a sustainability transition. The outputs include a synthesis of 11 global developments in the blue economy and 7 cross-cutting trends and trend projections. These may be valuable to marine scientists as a source of inspiration for a future research agenda or can be used as evidence for decision- and policymakers to deal with future uncertainties about the growth of the blue economy.peer-reviewe