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Trabajo presentado en el 6th International jellyfish blooms symposium, celebrado en Cape Town del 4 al 6 de noviembre de 2019., The aim of this study is to combine the abundance variability of jellyfish with the physical and oceanographic forcing at different spatial and temporal scales in the Balearic Sea. The most abundant and frequent species in this area but also in the whole Mediterranean Basin is Pelagia noctiluca. This species is totally pelagic during its entire life cycle as it lacks the polyp stage. Another peculiarity of P. noctiluca is that does dial vertical migration: surface at night and 80-100m during the day. For this ecology study of P. noctiluca multi-diverse technologies were employed: plankton nets, ROVs, CTDs, cameras equipped with laser (to study jellyfish abundance day and night), Lagrangian buoys, drones, several remote sensing images and hydrodynamical models, together with a jellyfish observation system implemented in the shoreline and continental shelf. The complete study demanded the use of both, an oceanography vessel with 24 h operability and also a big data assimilation facility. The combination of all these sources of data was analyzed to characterize this jellyfish variability and its connection with the physical environment at a resolution never achieved before.

Trabajo presentado en el 1st Meeting of the Iberian Ecological Society y XIV AEET Meeting (SIBECOL 2019), celebrados en Barcelona del 4 al 7 de febrero de 2019., Gelatinous zooplankton (cnidarians, ctenophores, tunicates)are gaining increasing interest from researchers and the general public. This is due to their ability to form large blooms that may interfere with human activities and have a strong impact on the affected ecosystems. Early detection and monitoring of such organisms is essential for effective management and mitigation of jellyfish outbreaks. Considering the impacts that jellyfish may have, there is surprisingly little data on their distribution and abundance, that is at least in part due to problems with the sampling and monitoring of these fragile organisms., This study was partially founded by the Slovenian Research Agency and Slovenian Ministry of Higher Education, Science and Technology (Program P1-0237, project “Raziskovalci-2.0-NIB-529024”),the project Medusas Baleares UCA2014020031,the Croatian Science Foundation under the project IP-2014-09-2945 andthe Mljet National Park.

Dakapoda iz nacionalnog parka Brijuni

Vertical distribution, population structure and chemical composition of a population of the schyphomedusan Aurelia sp. 5 wewre studied in the Mediterranean eurohaline lake on Mljet Island (Veliko jezero, the Southern Adriatic) where dense aggregations have been observed throughout the year. A majority of Aurelia was located in layer below the thermocline with temperature 13-19 0C over the most of the day during summer, whereas in October the population was shallower. The medusae migrated toward the surface at dusk but rarely crossed the thermocline. Elemental analysis of Aurelia revealed low dry specific carbon, nitrogen and phosphorus content ranging from 0.9-1.7%, 0.2-0.5%, amd 0.02-0.06% respectively. In addition to the direct predation impact on micro- and mesozooplankton, a clear positive response of heterotrophic bacteria to the presence of live and dead Aurelia was observed.

The present methodological paper presents a simple technique for digital imaging of small fish specimens using conventional flatbed scanners. Preparing such scanners with a plasticine pool enables fish specimens to be scanned under submerged conditions in water, ethanol or glycerine, depending on whether they are alive or preserved. This technique relies on a quickly prepared, less complicated setup than in photography and provides the opportunity to gain digital images of small fish in the laboratory as well as – with some restrictions – in the field. Lateral scans can be easily made of live specimens after narcotisation or of preserved fish. The scanning method yielded high-quality images of near- live colours of live fish and of preserved coloration. Images had good contrast, sharpness and illumination, minimal or no shadows and high resolutions when scanned on high-quality scanners. Depth of field in images was good for fishes of less than 20 cm length and less than 2 cm body width. The method is recommended for applications where digital images are required for body shape analyses, such as geometric morphometric approaches, for qualitative or quantitative analyses of coloration patterns, for fish (re-)identification, and as a basis for illustrations or for publication in electronic sources or print media.

According to the national legislation and by considering international documents on nature conservation, the Mediterranean endemic seagrass Posidonia oceanica was included in the latest edition of the Slovenian Red List of Rare and Endangered Species...

This paper describes a status of the sandbarshark, Carcharhinus plumbeus, in the Gulf of Trieste, as well as in the Adriatic.

Several anthropogenic factors are responsible for the decline of Cystoseira sensu lato (hereafter Cystoseira) forests along Mediterranean coasts. Some Cystoseira species are already regionally extinct, and their decline has been widely recorded. Sustainable and efficient techniques for the restoration of Cystoseira are needed. In this context, the objectives of this study were i) to analyse the reproductive traits of three populations of Gongolaria barbata from three nearby donor sites in the northern Adriatic Sea, assessing the differences in their reproductive potential and reproductive success; and ii) to evaluate the outplanting success in terms of the effectiveness of G. barbata restoration, in relation to the different donor and receiving sites (Miramare MPA and in front of the Marine Biology Station Piran - MBSP) and implemented methods (ex situ and hybrid method combining a mesocosm cultivation and a suspended culture in the field). After 2 weeks of cultivation in mesocosms, half of the tiles with germlings were transported to the receiving sites and placed on suspended lantern nets (hybrid method), which were later (after 3 months) transferred to the seabed on concrete plates with protective cages. The remaining tiles were placed on the seabed on concrete plates with protective cages after a 4-week culture (ex situ method). At both sites, lantern nets and plates were randomly placed at 3 m depth. Thallus length was measured monthly in each treatment. Seedlings in suspended culture showed lower performance at the Miramare MPA, most likely due to the unfavourable environmental conditions. The satisfactory results obtained at MBSP demonstrate the efficiency of the hybrid method and confirm its potential to reduce the cost and time required for cultivation. Since unpredictable climatic events pose the greatest threat to restoration performance, these challenges must be considered when establishing new restoration practices. Moreover, herbivore regulation is extremely urgent and should be planned and implemented on a larger regional scale.

The global decline of brown algal forests along rocky coasts is causing an exceptional biodiversity loss. Regardless of conservation efforts, different techniques have been developed for large-scale restoration strategies in the Mediterranean Sea. In this study we tested ex situ pilot restoration of Gongolaria barbata (=Treptacantha barbata) for the first time in Slovenian coastal waters. Healthy apical fronds of the species were collected and the development of recruits on clay tiles was followed under laboratory conditions for 20 days. Despite the experimental difficulties experienced, especially due to the lack of antibiotics to prevent the growth of the biofilm, G. barbata recruits were outplanted in the sea on two concrete plates with 48 tiles each, protected by purpose-built cages to avoid grazing by herbivorous fish. The high survival rate of juveniles after four months in the field (89% of the tiles on the plate that was constantly protected) suggests that outplanting G. barbata is an operable approach for restoration efforts in the northern Adriatic Sea. Our first experiment in Slovenian coastal waters provides new information for the optimization of the best practices during the laboratory cultivation and addresses the early steps of restoration and introduction of young thalli in the natural environment.