Fluxes and fate of particulate mercury in a contaminated coastal environment (Gulf of Trieste, northern Adriatic Sea)

As the result of historical mining activity in Idrija (western Slovenia), mercury (Hg) contamination in the Gulf of Trieste (northern Adriatic Sea) still represents an environmental issue of great concern for the local authorities. The element has been conveyed into the marine-coastal area by the Isonzo/Soča River freshwater inputs for centuries, mainly in association with the suspended particulate matter (SPM) during periods of medium-high discharge often corresponding to river plume events. The aim of this study was to investigate the occurrence of Hg bound to SPM (particulate Hg, PHg) in the coastal water twentyfive years after the mine closure and to assess sedimentary Hg fluxes in the northernmost sector of the Gulf, a shallow and sheltered embayment where the accumulation of fine sediments is promoted Sediment traps were placed both at the surface and at bottom water layers at four different sites and settling particles accumulated into each trap were collected approximately every 15 days during 6 sampling campaigns. In terms of grain size composition, the SPM consisted predominantly of silt (77.7 ± 10.1 %) and differences were observed among sites, water layers and sampling campaigns Concentrations of PHg were consistent with previous studies focused on the sediment compartment and ranged overall between 0.61 and 6.87 μg g-1 showing slightly higher values at the bottom (1.50 ± 0.52 and 2.31 ± 1.58 μg g-1 in surface and bottom water layers, respectively) most likely due to resuspension of fine particles enriched in Hg from bottom sediments. The estimated daily Hg fluxes associated with settling particles showed a notable variability, up to an order of magnitude, both in the surface water layer (3.07 – 94.6 μg m-2 d-1) and at the bottom (11.3 – 245 μg m-2 d-1) Moreover, a significant correlation (r = 0.762) was observed between Hg and SPM daily fluxes thus confirming that, still nowadays, periods of high PHg concentrations in the water column as well as of Hg sedimentary fluxes at the sea bottom roughly corresponds to higher SPM inputs from the Isonzo River

Circular Bedforms Due to Pit Foraging of Greater Flamingo Phoenicopterus roseus in a Back-barrier Intertidal Habitat

The Greater Flamingo Phoenicopterus roseus is known as an ecosystem engineer, rearranging sediment in peculiar bedforms as a consequence of its filter-feeding behaviour. In recent decades, the populations of the Greater Flamingo have notably increased, and now the species is one of the most abundant waterbirds in Mediterranean wetlands. Owing to its range expansion, it inhabits and exploits new and suitable foraging sites detectable by foraging structures left on the sediment. There are few images of the foraging morphologies in the literature, possibly due to their ephemeral nature and difficulty in detecting them. In this manuscript, we present a very detailed UAV (Unmanned Aerial Vehicle) image of an aggregate of pit foraging structures of Greater Flamingo discovered on a back-barrier washover fan in the Marano and Grado Lagoon (Northern Adriatic, Italy)

Plataforma de inovação agrária de Moçambique - informações geoespaciais para a gestão dos recursos naturais e desenvolvimento agrícola.

O projeto Embrapa?Moçambique é baseado nas similaridades edafoclimáticas existentes entre as savanas moçambicanas e o Cerrado brasileiro e objetiva o levantamento e o mapeamento das potencialidades dos recursos naturais de Moçambique. Neste trabalho, foi gerado um mosaico digital de Moçambique a partir de imagens do satélite Landsat 8, do ano de 2013, e foram estabelecidos critérios para: a definição das órbitas-ponto; o processamento digital das imagens; o estabelecimento de um layout; a sobreposição de planos de informações de interesse para os grupos de pesquisa brasileiro e moçambicano, como localização de parques, reservas, rios principais; entre outros. Como resultado alcançado, destaca-se a geração e disponibilização do mosaico digital composto por 49 cenas, que dará apoio para a análise preliminar, em ambiente de sistemas de informação geográfica, para o levantamento de uso e cobertura das terras de Moçambique

Quantifying transgressive coastal changes using UAVs: dune migration, overwash recovery, and barrier flooding assessment and interferences with human and natural assets

The advantages derived from the use of Uncrewed Aerial Vehicles (UAVs) are well-established: they are cost-effective and easy to use. There are numerous environmental applications, particularly when monitoring contexts characterized by rapid morphological changes and high rates of sediment transport, such as coastal areas. In this paper, three different case studies of survey and monitoring with high resolution and accuracy obtained through the use of UAVs are presented; these concern transgressive coastal sites. Results allow for the definition and quantification of coastal landforms and processes, including: (i) The anatomy of a parabolic dune and the rate of landward migration that could interfere with a tourist settlement; (ii) The mode and timing of morphological recovery and realignment of a barrier island overwashed by storm surge episodes; and (iii) The potential flood risk of a progradational spit that is a nesting site of a species of migratory breeding birds of conservation concern. The results demonstrate and confirm that, through a good coupling of drone-sensed quality data and accurate topographic control, quantitative estimates that are useful in assessing the impacts of natural processes involving both human and natural assets can be obtained

Environmental and Oceanographic Conditions at the Continental Margin of the Central Basin, Northwestern Ross Sea (Antarctica) since the Last Glacial Maximum

The continental margin is a key area for studying the sedimentary processes related to the advance and retreat of the Ross Ice Shelf (Antarctica); nevertheless, much remains to be investigated. The aim of this study is to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin slope–basin system using a multidisciplinary approach, including integrated sedimentological, micropaleontological and tephrochronological information. The analyses carried out on three box cores highlighted sedimentary sequences characterised by tree stratigraphic units. Collected sediments represent a time interval from 24 ka Before Present (BP) to the present time. Grain size clustering and data on the sortable silt component, together with diatom, silicoflagellate and foraminifera assemblages indicate the influence of the ice shelf calving zone (Unit 1, 24–17 ka BP), progressive receding due to Circumpolar Deep Water inflow (Unit 2, 17–10.2 ka BP) and (Unit 3, 10.2 ka BP–present) the establishment of seasonal sea ice with a strengthening of bottom currents. The dominant and persistent process is a sedimentation controlled by contour currents, which tend to modulate intensity in time and space. A primary volcanic ash layer dated back at around 22 ka BP is correlated with the explosive activity of Mount Rittmann

Multidisciplinary assessment and prediction tools addressing coastal vulnerability to erosion and sea level rise. Lesson learnt from the RITMARE Project

Natural processes and human activities are strongly connected, and sometimes con icting, in the evolution of coastal and transitional environments. The strong anthropic pressure on coastal regions, together with the e ects of a changing climate, demands nowadays more pressingly for e cient tools to characterise and predict the behaviour of such systems in order to de ne appropriate response strategies. This requires a deep understanding of the connections among di erent drivers and di erent scales, a multidisciplinary challenge in which heterogeneous data, approaches and scales need to be framed within a consistent dynamical description. To this aim, a speci c research line was dedicated to \u201cCoastal Vulnerability to Erosion and Sea Level Rise\u201d within the RITMARE Project, supported by the Italian Ministry of University and Research with the purpose of integrating the Italian Marine community in shared research elds in the period 2012-2017. The activities carried out in this framework have been moving along interconnected branches tackling the themes related with sea level rise, ocean modelling, and geomorphological assessment in present conditions and in di erent climate change scenarios, with an eye on the exploitation of marine sand as a strategic resource. In this contribution we review the main outcomes of this multidisciplinary and coordinated research. Besides discussing the advances and the possibilities from state-of-the art technologies and methodologies, we point out that a coordinated use of the described tools should be promoted in the design of survey and monitoring activities, as well as in the exploitation of already collected data. Expected outcomes of this strategy include the implementation of improved policies and infrastructures for coastal protection, anked by reliable short-term forecasting systems and e cient rapid response protocols, in the framework of an integrated coastal planning at the multi-decadal scale