Search

1 - The quali-quantitative analysis of phytoplankton guild is usually carried out according to the method of Uthermöl (or sedimentation method), but in each step can be present a component of error that can affect the reliability of the final result, from sampling to data analysis. 2 - The following work is intended to focus attention on an important aspect of the phytoplankton analysis: the fixation, with the aim of assessing the effect of two chemical fixatives, formalin and Lugol's solution, on the taxonomic composition and size structure of phytoplankton guilds. Accordingly, water samples were collected from three different water bodies, coastal marine area facing the Alimini Lake (Southern Adriatic Sea), transitional water (Alimini Grande Lake) and freshwater (Fontanelle Lake). The three water bodies are characterized by a different taxonomic structure of phytoplankton guilds due to difference in chemical-physical and hydrodynamic conditions. 3 - The samples were fixed and then analyzed according to a monthly time series for a period of 125 days. 4 - This study clearly shows that do not exist a better fixative, but on the basis of the phytoplankton classes observed in a sample we could prefer one of the two fixative. [ABSTRACT FROM AUTHOR]

1 - A series of experimental researches highlighted the role of morphometric parameters of phytoplankton guilds as descriptors of the ecological status of transitional water ecosystems (TWs). 2 - However, at present, standardized or common methodologies for their use do not exist. In this work, we develop a procedure for the determination of biovolume and surface area in phytoplankton guilds of Mediterranean TWs. 3 - Phytoplankton biovolume and surface area are included among the most studied morphometric descriptors. They can be estimated by associating the algae with similar geometric forms and determining the volume of these by measuring the linear dimensions required for its calculation under the light microscope. 4 - Here, a set of geometric models is suggested for calculating the cell biovolumes and surface area of 235 phytoplankton genera, deriving from the analysis of 869 phytoplankton species, found in transitional water ecosystems of the Mediterranean Ecoregion. The equations were designed to minimize the effort of microscopic measurements. 5 - The similarities and differences between the geometric models here proposed and previously published are discussed. [ABSTRACT FROM AUTHOR]

1 - The methodological issues in the analysis of phytoplankton guilds in transitional waters, using inverted microscopy (Utermöhl technique), will showing and discuss, in reference to UNI EN 15204, particularly regarding sedimentation and counting steps. 2 - The statistical processes for the validation of the two steps will showing and discuss [ABSTRACT FROM AUTHOR]

In this work, freshwater microplastic samples collected from four different stations along the Italian Po river were characterized in terms of abundance, distribution, category, morphological and morphometrical features, and polymer type. The correlation between microplastic category and polymer type was also evaluated. Polymer identification was carried out developing and implementing a new and effective hierarchical classification logic applied to hyperspectral images acquired in the short-wave infrared range (SWIR: 1000-2500 nm). Results showed that concentration of microplastics ranged from 1.89 to 8.22 particles/m 3 , the most abundant category was fragment, followed by foam, granule, pellet, and filament and the most diffused polymers were expanded polystyrene followed by polyethylene, polypropylene, polystyrene, polyamide, polyethylene terephthalate and polyvinyl chloride, with some differences in polymer distribution among stations. The application of hyperspectral imaging (HSI) as a rapid and non-destructive method to classify freshwater microplastics for environmental monitoring represents a completely innovative approach in this field., (© 2022. The Author(s).)

Records of the cumacean genus Iphinoe from Italian coasts are reported with relevant data on the habitat, morphology and geographical distribution of each species. Seven Iphinoe species from the Italian coasts were recorded and are presented here with their own distributional ranges; the description of a new species, Iphinoe daphne n. sp. is also given.                Our results extend the known distribution of some species to new areas of the Mediterranean Sea and suggest that the species Iphinoe adriatica Bâcescu, 1988 can be considered as a nomen dubium, while the presence of I. trispinosa along the Italian coast is doubtful.Finally, a dichotomous key for all Mediterranean Iphinoe species is provided.

Refined baseline inventories of non-indigenous species (NIS) are set per European Union Member State (MS), in the context of the Marine Strategy Framework Directive (MSFD). The inventories are based on the initial assessment of the MSFD (2012) and the updated data of the European Alien Species Information Network, in collaboration with NIS experts appointed by the MSs. The analysis revealed that a large number of NIS was not reported from the initial assessments. Moreover, several NIS initially listed are currently considered as native in Europe or were proven to be historical misreportings. The refined baseline inventories constitute a milestone for the MSFD Descriptor 2 implementation, providing an improved basis for reporting new NIS introductions, facilitating the MSFD D2 assessment. In addition, the inventories can help MSs in the establishment of monitoring systems of targeted NIS, and foster cooperation on monitoring of NIS across or within shared marine subregions., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Productive Failure (PF) facilitates students' conceptual knowledge by delaying instruction until after problem solving. While PF is well investigated in middle and high school students, little is known about its effectiveness in younger students. Studies in younger samples, which implemented delayed instruction designs similar to those used in PF studies, showed mixed results. However, these studies did not implement two core design components of PF: (1) contrasting and comparing student-generated solutions and the canonical solution during the instructional phase (contrasting activity), and (2) students' collaboration in small groups during the initial problem-solving phase. Both components can be expected to contribute to the effectiveness of PF. In a quasi-experimental study with 228 fifth graders, we implemented the first component (contrasting activity) with all students to establish whether under this condition, problem solving prior to instruction would be more effective for younger students' conceptual knowledge acquisition than direct instruction (i.e., problem solving after instruction). Further, we experimentally tested the effect of the second component (collaborative vs. individual problem solving) on students' conceptual knowledge and the number of solution ideas generated during initial problem solving. We found no empirical support for either of our hypotheses. To explore the extent to which students' collaboration actually achieved its potential and relates to students' conceptual knowledge and solution ideas in PF, we conducted analyses of collaborative processes. Our study adds to the mixed results regarding the superiority of problem solving prior to instruction for young students, thus opening the discussion about age-related prerequisites as boundary conditions for PF., Competing Interests: The authors declare no competing interests.

Marine litter is a threat to marine life and an economic burden for coastal communities, but efforts to address the issue are hampered by the lack of data for many countries. We performed the first harmonized assessment of seafloor litter (trawl and visual surveys) in six countries of the Adriatic-Ionian macroregion. Seafloor litter showed an uneven distribution throughout the area, with large differences in litter densities and composition among countries and locations. An emerging problem in the area resulted in short-term & single-use objects that represented the largest fraction of litter. Packaging was the economic sector contributing most to seafloor litter on the continental shelf and upper slope, while in some areas aquaculture (mussel farming) represented a key activity producing marine litter. In coastal areas and bays (e.g. Boka Kotorska bay, Montenegro), seafloor litter was mainly related to construction activities and electronic goods, which are a consequence of fly-tipping/illegal dumping., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The abundance, composition and sources of marine litter were determined on beaches located in the seven countries of the Adriatic-Ionian macroregion, namely Albania, Bosnia and Herzegovina, Croatia, Greece, Italy, Montenegro and Slovenia. A total of 70,581 marine litter items were classified and recorded through one-year long surveys carried out in 31 sites. The average litter density of 0.67 items/m 2 found within this study is considered to be relatively high. The beaches investigated differed in terms of human-induced pressures; their majority is classified either as semi-urban or semi-rural, while very few beaches could be characterized as urban or remote/natural. The majority of litter items were made of artificial/anthropogenic polymer materials accounting for 91.1% of all litter. Litter from shoreline sources accounted for 33.4% of all litter collected. The amount of litter from sea-based sources ranged in the different countries from 1.54% to 14.84%, with an average of 6.30% at regional level., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

According to the European Water Framework Directive, the ecological status (ES) of a water body is determined by comparing observation data with undisturbed Reference Conditions (RCs). Defining RCs is crucial when evaluating the ES of a water body as it strongly affects the final outcome of any index application. Identifying RCs by observing real sites is not feasible in many marine environments, such as the Emilia-Romagna coast (Italy, N-Adriatic Sea). We used a statistical approach on a large dataset to derive RCs for the application of the benthic index M-AMBI in this area. We then applied M-AMBI to samples collected along a gradient of presumed environmental disturbance. The results put 14.8% of the Emilia-Romagna samples in "High" ES, 60.2% in "Good", 23.0% in "Moderate" and 2.0% in "Poor", showing a spatial gradient of improving quality. These results are in agreement with the extensive ecological knowledge available for this area., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Atmospheric nitrogen compounds play a critical role in tropospheric photochemistry and are crucial to understand the chemical and physical evolution of atmospheric pollutants in polar areas. Measurements of these species in remote areas are rare, although their relevance is well established. Sampling campaigns of gaseous and particulate atmospheric trace species were performed in Arctic and in Antarctica during three consecutive years (1997-1999), using a proper combination of annular denuders and filter pack. After sampling, the ionic species were extracted with aqueous solutions and analysed by means of ion chromatography. Quality assurance on the sampling and analytical steps allowed accurate and precise measurements of all relevant compounds, which are thought to be important to nitrogen chemistry, at very low concentration levels. In addition, the measurements also included a multistage low-pressure impactor for the collection of particulate matter in different size regions (0.035-15.9 mm). Results obtained from these campaigns demonstrate that the minor components may be measured at levels as low as a few nanograms per cubic meter. The reported concentrations are to be considered among the first observations of nitrogen containing compounds in polar sites.