Search the repository

A+ | A- | | SLO | ENG

Abstract: The purpose of this preliminary study was to define the vertical migration pattern in the dinoflagellate community in the shallow coastal sea. Migrations were followed in an area of mussel farming, through two 24-hour samplings, first during mixed and second during stratified water column conditions. Despite variable physical environment we were able to follow vertical migrations of some autotrophic dinoflagellate species in the period of stratified water column. The results also suggest that Heterocapsa sp. may preserve its vertical migration pattern also under mixed conditions. Migrations were observed also for Dinophysis sacculus that can cause DSP problems in the area.
Keywords: dinoflagellates, vertical migrations, eastern Adriatic coast, Adriatic Sea, dynamic environment, coastal sea, Adriatic
Published in DiRROS: 05.08.2024; Views: 51; Downloads: 19
Full text (338,82 KB)
This document has many files! More...

Abstract: The Indo-Pacific egg-carrying copepod Pseudodiaptomus marinus Sato, 1913 was recorded for the first time in the Port of Koper, Slovenia (Gulf of Trieste) in February 2015. This is the fourth finding of this species in the Mediterranean Sea, and the third for the Adriatic Sea. A rather high abundance of 73 ind. m-3 was recorded, which is considerably higher than previous findings in the Adriatic. Maritime transport is presumed to be the main cause of its introduction, primarily through ballast water release. Repeat sampling in May confirmed the presence of this copepod, indicating the possibility that the species has established a stable population in the Port of Koper.
Keywords: copepods, Adriatic Sea, mesozooplankton, ballast waters
Published in DiRROS: 29.07.2024; Views: 92; Downloads: 36
Full text (358,14 KB)
This document has many files! More...

Abstract: We examine the large-scale distribution patterns of the nano- and microphytoplankton collected from 145 oceanic stations, at 3 m depth, the 20% light level and the depth of the sub-surface chlorophyll maximum, during the Malaspina-2010 Expedition (December 2010-July 2011), which covered 15 biogeographical provinces across the Atlantic, Indian and Pacific oceans, between 35°N and 40°S. In general, the water column was stratified, the surface layers were nutrient-poor and the nano- and microplankton (hereafter phytoplankton, for simplicity, although it included also heterotrophic protists) community was dominated by dinoflagellates, other flagellates and coccolithophores, while the contribution of diatoms was only important in zones with shallow nutriclines such as the equatorial upwelling regions. We applied a principal component analysis to the correlation matrix among the abundances (after logarithmic transform) of the 76 most frequent taxa to synthesize the information contained in the phytoplankton data set. The main trends of variability identified consisted of: 1) A contrast between the community composition of the upper and the lower parts of the euphotic zone, expressed respectively by positive or negative scores of the first principal component, which was positively correlated with taxa such as the dinoflagellates Oxytoxum minutum and Scrippsiella spp., and the coccolithophores Discosphaera tubifera and Syracosphaera pulchra (HOL and HET), and negatively correlated with taxa like Ophia-ster hydroideus (coccolithophore) and several diatoms, 2) a general abundance gradient between phytoplankton-rich regions with high abundances of dinoflagellate, coccolitho-phore and ciliate taxa, and phytoplankton-poor regions (second principal component), 3) differences in dominant phytoplankton and ciliate taxa among the Atlantic, the Indian and the Pacific oceans (third principal component) and 4) the occurrence of a diatom-dominated assemblage (the fourth principal component assemblage), including several pennate taxa, Planktoniella sol, Hemiaulus hauckii and Pseudo-nitzschia spp., in the divergence regions.
Keywords: sea, phytoplankton, research programmes, ocean expeditions, Malaspina 2010, distribution, ocean sampling, Atlantic Ocean, Pacific, Indian Ocean
Published in DiRROS: 25.07.2024; Views: 204; Downloads: 66
Full text (8,31 MB)
This document has many files! More...

Abstract: For mitigation of the effects of pollution, the media, policy makers and, in turn, the scientific community and industry each provide contributions through development of a sense of urgency, and with guidelines and solutions. For non-indigenous species (NIS) that can frequently have negative impacts on the native biota, this is often conveyed in an emotive way to the general public, who are typically keen to help and to get personally involved. This might be through organization of cleaning campaigns, influence on the media, or collaboration with scientists, to inform them of the local presence and abundance of NIS. Alternatively, they might proactively develop technological solutions themselves. To assess the current state of affairs, we reviewed the presence and effects of NIS in the Mediterranean Sea. As so often, any well-planned and successful activity is directly linked to financing, or a lack thereof, and this leads to sometimes untargeted and sporadic measures that are developed within a project or over a limited timeframe, without any sustainability measures. Therefore, we also assessed the activities and strategies that have been financed in this area of NIS mitigation. Based on this review of the presence and impact of NIS, and previous and ongoing activities, we propose a new paradigm to mitigate such pollution: the 8Rs model (i.e., Recognize, Reduce, Replace, Reuse, Recycle, Recover/Restore, Remove, and Regulate). This model extends from the more traditional 3Rs model (i.e., Reduce, Reuse, and Recycle) that is often used and promoted for innovative waste management strategies. Importantly, the 8Rs model can be applied sequentially, for either prevention of NIS introduction, or preparation of mitigation measures. The 8Rs model was constructed based on Mediterranean NIS, although we believe it can be applied to other sources of pollution and other geographic areas. Importantly, the 8Rs model represents a general framework to organize and categorize future pollution mitigation strategies. This approach is essential for development of any action plan to influence the administrative and financial decision makers who essentially enable these activities, and therefore who have important roles in the guarantee of sustainability of these actions, and the creation of innovative societies.
Keywords: non-indigenous species, pollution mitigation, pollution mitigation, 8Rs model, quadruple helix, Mediterranean Sea, citizen science, communication, sustainability
Published in DiRROS: 22.07.2024; Views: 102; Downloads: 108
Full text (2,04 MB)
This document has many files! More...

Abstract: Marine primary producers are highly sensitive to environmental deterioration caused by natural and human-induced stressors. Following the Water Framework Directive and the Marine Strategy Framework Directive requirements, the importance of using the different primary producers of the coastal marine ecosystem (pelagic: phytoplankton and benthic: macroalgae and angiosperms) as appropriate tools for an integrated assessment of the ecological status of the coastal environment has been recognized. However, the processes by which water column characteristics and phytobenthic indicators are linked have not been systematically studied. Based on a large dataset from three Mediterranean sub-basins (Adriatic, Ionian and Aegean Seas) with different trophic conditions, this study aims to explore the coupled responses of benthic and pelagic primary producers to eutrophication pressures on a large scale, focusing on the structural and functional traits of benthic macroalgal and angiosperm communities, and to investigate the key drivers among the different eutrophication-related pelagic indicators (such as nutrient and Chl-a concentrations, water transparency, etc.) that can force the benthic system indicators to low ecological quality levels. In addition to the effects of high nutrient loading on phytoplankton biomass, our results also show that increased nutrient concentrations in seawater have a similar effect on macroalgal communities. Indeed, increasing nutrient concentrations lead to increased coverage of opportunistic macroalgal species at the expense of canopy-forming species. Most structural traits of Posidonia oceanica (expressed either as individual metrics: shoot density, lower limit depth and lower limit type, or in the context of PREI index) show opposite trends to increasing levels of pressure indicators such as ammonium, nitrate, phosphate, Chl-a and light attenuation. Furthermore, our results highlight the regulating effect of light availability on the ecological status of seagrass meadows (Posidonia oceanica and Cymodocea nodosa). Increasing leaf length values of C. nodosa are closely associated with higher turbidity values linked to higher phytoplankton biomass (expressed as Chl-a). Overall, the coupling of pelagic and benthic primary producers showed consistent patterns across trophic gradients at the subregional scale.
Keywords: macroalgae, seagrasses, phytoplankton, eutrophication, Mediterranean Sea
Published in DiRROS: 17.07.2024; Views: 90; Downloads: 82
Full text (3,29 MB)
This document has many files! More...