State of the Art of the Marine Non-Indigenous Flora and Fauna in Slovenia

Authors provide the state of knowledge on marine non-indigenous species in waters off Slovenia. According to published records and authors unpublished data at least 15 non-indigenous species were up to date recorded in the Slovenian part of the Adriatic sea. Eleven species were considered as established and four species as casual. The vectors of introduction are various, comprising Lessepsian migration, mariculture and shipping. The majority of non-indigenous taxa were recorded in the mediolittoral belt and coastal lagoons. The low number of non-indigenous species so far recorded in the Slovenian part of the Adriatic sea could be explained by various factors. Among them, the most reasonable are the lack of scientific attention, the small proportion of Slovenian Sea and low winter temperatures, which represents a physiological barrier for the survival of newcomers. The number of recorded species is far from being satisfactory. Therefore, we expect that the list of non-indigenous species will be enlarged in the nearby future

Mollusc fauna associated with the Cystoseira algal associations in the Gulf of Trieste (Northern Adriatic Sea)

Mollusc assemblages associated with Cystoseira associations were sampled in the southern part of the Gulf of Trieste during the summers of 2008 and 2012. Samples were collected by SCUBA diving in the infralittoral belt (from 1 to 4 m depth). The surface within frames of 20 x 20 cm was scraped off with samples were collected by hand or with an air-lift sampler. Four erected algal species were found: Cystoseira barbata, C. compressa, C. corniculata and Halopithys incurva. A total of 69 species of molluscs were identified in those associations. Gastropoda were dominant, with the highest species richness and abundance, followed by Bivalvia and Polyplacophora. A large number of juveniles were found, proving the importance of Cystoseira associations for mollusc recruitment. Differences in composition, structure and abundance of mollusc assemblages were found for sites dominated by different algal species, and correspond to different morphology and degree of development of canopy-forming species. The present study confirms that the dominant algal species within Cystoseira associations strongly influence, although at different levels, abundance and distribution of mollusc assemblages in the Northern Adriatic Sea

New insights on the biological parameters of the exploited cuttlefish Sepia officinalis L. (Mollusca: Cephalopoda) in the northern Adriatic Sea in relation to the main fishing gears employed

The cuttlefish (Sepia officinalis Linnaeus 1758) represents one of the most important coastal fishery resources of the Mediterranean Sea. For Italy, 45% of cuttlefish landings (2,328 t) originates from coastal regions of the northern Adriatic Sea: Veneto, Marche, Emilia Romagna and Friuli Venezia Giulia. In terms of economic value this species represents about 8% (~€ 16.5 million) of the production from this basin. From May 2004 to October 2005, cuttlefish were purchased from commercial landings of the Grado fishery fleet. At least 30 specimens were randomly taken each month from each fishing method employed for this species: bottom trawl (cod end mesh size 40 mm), rapido trawl, trammel net (mesh size of inner panel 30 mm) and cuttlefish specific trap. The main biological aspects, such as size, sex ratio, reproductive stage and diet in relation to both the season and type of fishing gear were analyzed. 1,495 specimens, ranging from 3.5 to 18.0 cm mantle length, were analyzed. In relation to the observed size and reproductive stage of individuals caught, trammel nets and cuttlefish traps both appeared to target sexually mature individuals, whilst trawling gear were not selective for either recruits or spawners. In total 34 prey taxa were found in the stomachs of S. officinalis: crabs and bony fish species were the most important prey, although the latter appeared mostly in the largest specimens. Finally the fullness index revealed that cuttlefish caught by trawling were more suitable for diet analysis than those caught by static gear. In this way the contribution of the present paper was to give new insights on the biological parameters of this species in relation to the main fishing gears employed in the northern Adriatic Sea

Microplastic Contamination in Protected Areas of the Gulf of Venice

We investigated the concentration and composition of plastics in 7 Special Areas of Conservation (SACs) from the Gulf of Venice (northern Adriatic Sea). A total of 42 sediment samples were analyzed from 21 sites from 2017 to 2018. All sites except one were found to be polluted by plastics, with density ranging between 2250 and 28.4 items kg−1. Microplastics ranged from 100 to 61.6% of the collected plastics. Fragments were more represented than filaments. The greatest plastic concentrations were generally recorded in western SACs. Identification through FT-IR spectroscopy evidenced the presence of 8 polymer types: in western SACS, the majority were low-density polymers (PE, PP, PS, and TPU), while in eastern SACs they were high-density polymers (PET, nylon, and PVC). In addition to the role of large rivers (all on the western side of the Gulf) in conveying plastics into the sea, a possible role of the cyclonic water circulation of the northern Adriatic Sea on distribution and composition of plastics along the Gulf coasts is likely

Report of the JRC’s Descriptor 2 workshop in support to the review of the Commission Decision 2010/477/EU concerning MSFD criteria for assessing Good Environmental Status for NIS

The MSFD workshop on non-indigenous species (NIS, MSFD D2), held in Ispra JRC (10th-11th of September 2015) aimed to provide clear proposals and conclusions on some of the outstanding issues identified in the D2 review manual (May 2015 consultation version: D2 review manual: https://circabc.europa.eu/sd/a/cd4bbd6a-454a-40db-b805-52fb195d4e56/COMDEC_Review_D2_V6.pdf) in the broader context of support to the review of Commission Decision 2010/477/EU. This report is complementing the Commission Decision 2010/477/EU review manual (JRC96884) and presents the result of the scientific and technical review concluding phase 1 of the review of the Commission Decision 2010/477/EU in relation to Descriptor 2. The review has been carried out by the EC JRC together with experts nominated by EU Member States, and has considered contributions from the GES Working Group in accordance with the roadmap set out in the MSFD implementation strategy (agreed on at the 11th CIS MSCG meeting). The main issues addressed and tackled in this workshop’s report are: - Proposed changes in D2 assessment criteria; - Indicators and methodological standards; - GES threshold values and reference points; - Way forwar

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia)

Establishing thresholds

The Workshop on ‘Establishing thresholds: workshop on the Marine Strategy Framework Directive (MSFD) Newly Introduced Non-Indigenous Species (NIS) (D2C1)’ took place online on the 24th November 2022, aiming at discussing and making progress towards establishing threshold values for the criterion D2C1. The workshop was organised by the Joint Research Centre (JRC), in collaboration with representatives of the Regional Sea Conventions (RSCs), under the MSFD Descriptor 2 Core Group, in the context of the MSFD Common Implementation Strategy Good Environmental Status Working Group. The participants to the workshop included academic and public authorities’ experts on MSFD NIS, RSCs representatives, the European Environment Agency (EEA), and Commission services. The workshop enabled sharing information on the state-of-the-art approaches on monitoring and assessment of D2C1 within Regional Seas and on the application of the time series analysis as a follow-up to Tsiamis et al. (2021) recommendations for setting threshold values. The discussion focused on ensuring comparability of approaches, how to account for uncertainties, and on areas for improvement. It was acknowledged that activities of RSCs are instrumental in coordinating the science and management of marine NIS. The various levels of monitoring across the North-East Atlantic Ocean, the Mediterranean Sea, the Baltic Sea and the EU Countries explain different methodological approaches for setting thresholds, while the limited monitoring restrict the application of these methodologies in the Black Sea. The workshop identified four main areas for improvements: i) establishment of acknowledged baselines for NIS introductions, ii) make further progress in monitoring and analysis methods, iii) agree on thresholds for new NIS introductions and, iv) ensure coherence and consistency between national and regional reports. The JRC will seek for opportunities to discuss and advance on identified areas for improvement with the MSFD national appointed NIS experts The MSFD Descriptor 2 (D2) Core Group will contribute to the discussions

First contribution to the knowledge of coralline algae distribution in the Slovenian circalittoral zone (Northern Adriatic).

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A new Dasysiphonia (Delesseriaceae, Rhodophyta) species discovered in the North Adriatic Sea (Mediterranean)

Dasysiphonia I.K. Lee & J.A. West is a genus of the family Delesseriaceae (Rhodophyta) including 9 taxonomically accepted species (Guiry and Guiry, 2023). Among these, only one is currently reported in the Adriatic Sea (Mediterranean): Dasysiphonia japonica (Yendo) H.-S. Kim. This invasive red seaweed is native to the Hokkaido Island (Guiry and Guiry, 2023), one of the major oyster production areas in Japan (about 700 tons a year; Hasegawa et al., 2015). The species was first recorded in Europe near an oyster culture area in Brittany (France) in 1984 and in Galicia (Spain) in 1988 (Sjøtun et al., 2008). The introduction into Europe and its dispersal in the Mediterranean is most likely due to its association with the Pacific oyster Magallana gigas (Thunberg, 1793) (Sjøtun et al., 2008). This seaweed is spreading aggressively in coastal waters with blooms that have been associated with fish die-offs (Fofonoff et al., 2018). In this study we reported the first finding of another species belonging to the genus Dasysiphonia in the Mediterranean Sea. Samplings of this taxon were carried out by the Marine Biology Station Piran of the National Institute of Biology in Slovenian coastal waters, and thalli of the putative new species were analyzed both by molecular and morphological methods and compared with the other known taxa. Samples of the invasive D. japonica were collected in different sites of the Venice Lagoon (Italy) during monitoring campaigns of the project MoVEco to assess the ecological status of the lagoon in the framework of the European Water Directive (2000/60/EC). In the phylogenetic reconstruction, based on the plastid rbcL gene, the Slovenian samples were well distinct from all the species included in the genus Dasysiphonia as well as from those which were recently transferred from the sister genus Dasya (Cassidy et al., 2022). The morphological characters were analyzed and compared with those of the species D. japonica in order to estimate the invasive potential of this new taxon