Analysis of Sea Storm Events in the Mediterranean Sea: The Case Study of 28 December 2020 Sea Storm in the Gulf of Naples, Italy

The coastline of the Gulf of Naples, Italy, is characterized by a series of infrastructures of strategic importance, including touristic and commercial ports between Pozzuoli to Sorrento, main roads, railways, and urban areas. Furthermore, the Gulf of Naples hosts an intense traffic of touristic and commercial maritime routes. The risk associated with extreme marine events is hence very significant over this marine and coastal area. On 28 December 2020, the Gulf of Naples was hit by an extreme sea storm, with severe consequences. This study focuses on the waterfront area of Via Partenope, where the waves overrun the roadway, causing massive damage on coastal seawall, road edges, and touristic structures (primarily restaurants). Based on the analysis of the meteorological evolution of the sea storm and its effects on the waterfront, we suggest that reflective processes induced on the sea waves by the tuff cliffs at the base of Castel dell’Ovo had an impact in enhancing the local-scale waves magnitude. This caused in turn severe flooding of the roadway and produced widespread damage along the coast. The analysis of the event of 28 December 2020, also suggests the need of an effective mitigation policy in the management of coastal issues induced by extreme sea storm events. Wind-based analysis and prediction of the sea wave conditions are currently discussed in the literature; however, critical information on wave height is often missing or not sufficient for reliable forecasting. In order to improve our ability to forecast the effects of sea storm events on the coastline, it is necessary to analyze all the components of the coastal wave system, including wave diffraction and reflection phenomena and the tidal change. Our results suggest in fact that only an integrated approach to the analysis of all the physical and anthropic components of coastal system may provide a correct base of information for the stakeholders to address coastal zone planning and protection.

Geomorphological Changes of a Migrating Sandbank: Multidecadal Analysis as a Tool for Managing Conflicts in Coastal Use

While beach erosion and sand loss are typically of great concern to the tourism industry, managing rapid morphological changes linked to large amounts of moving sediments is the challenge facing Grado, an important seaside resort in the northern Adriatic, Italy. The cause of the unusual management conflict is the presence of the Mula di Muggia Bank, a nearshore depositional system made up of relict and active migrating sandbanks extending up to 2 km seawards from the touristic beachfront. A reconstruction of the morpho-sedimentary evolution of the coastal system over a 200-year period was done using a large dataset which includes historical cartography, topographic maps, aerial photos and topo-bathymetric surveys. The results show the growth of a significant urban development aimed at creating a tourist destination by occupying the waterfront along fetch-limited coastal tracts with very shallow water and scarce hydrodynamics. Furthermore, a number of sandy dynamic landforms (longshore migrating bars, a bypass corridor, an ebb-tidal delta) and accumulation zones attest to a sediment excess which can be mostly attributed to the eastern river supplies. The progressive constant migration rate of 12.6 my−1 allowed the bank to induce the expansion of the low-energy silty backbarrier environment, characterised by abundant seagrass meadows a short distance directly in front of the tourist beaches of Grado. As a result of historical analysis and more current observations, areas with diverse morphosedimentary features and with varying tourist/recreational, ecological, and conservation values have been identified. These can be considered as basic units for future accurate planning and re-evaluation of coastal management choices to balance environmental protection and tourist use. A soft coastal defence approach is proposed which includes either the preservation of specific environments or the proper use of excess sand for beach nourishment via periodic dredging or sediment bypassing.

Mathematical modeling of the pollutant distribution process in the Gelendzhik Bay

Currently, the pollution problem of coastal sea waters in the resort areas of the Black Sea is becoming increasingly urgent. Thousands of chemicals, industrial and household waste enter the water basins every year, which significantly worsens the state of marine waters. Storm drains are saturated with pollutants at precipitation, washing out various chemical compounds, garbage and transporting them to the sea. In addition, a separate problem is poorly self-cleaning of the Gelendzhik Bay. A complete water change occurs in the period from 1 to 6 days. This paper covers the development, research and numerical implementation of a mathematical model of the pollution transport, including petroleum products, in the Gelendzhik Bay taking into account a number of important hydrodynamic and hydrophysical factors, methods of its numerical implementation, which allow predictive modeling of the pollution spread in shallow water systems in a limited time. A hydrobiological model of a coastal system characterized by significant depth differences has been developed. A three-dimensional mathematical model is designed to research the transformation of the phosphorus, nitrogen and silicon forms in the plankton dynamics problem. It takes into account the convective and diffusive transports, absorption and release of nutrients by phytoplankton, salinity, temperature, oxygen regime, etc. Using a spatial-three-dimensional hydrodynamics model, taking into account the physical properties of water environment of the coastal system, calculation results are used as input data for the development of scenarios for the dynamics of transport processes and the transformation of pollution biogenic elements in the water.

Microscale and Mesoscale Aeolian Processes of Sandy Coastal Foredunes from Background to Extreme Conditions

Aeolian transport affects beach and foredune pre-storm morphologies, which directly contribute to storm responses. However, significant spatiotemporal variation exists within beach-dune systems regarding how biotic and abiotic factors affect topography. There are multiple metrics for quantifying topographic change, with varying pros and cons, but understanding how a system changes across spatiotemporal scales relative to varying forcings is necessary to accurately model and more effectively manage these systems. Beach and foredune micro- and mesoscale elevation changes (Δz) were quantified remotely and in situ across a mid-Atlantic coastal system. The microscale field collections consisted of 27 repeat measurements of 73 elevation pins located in vegetated, transitional, and unvegetated foredune microhabitats over three years (2015 to 2018) during seasonal, event-based, and background wind-condition collections. Unoccupied aerial System (UAS) surveys were collected to link microscale point Δz to mesoscale topographic change. Microscale measurements highlight how Δz varies more pre- to post-event than seasonally or monthly, but regardless of collection type (i.e., seasonal, monthly, or event-based), there was lower Δz in the vegetated areas than in the associated unvegetated and partially vegetated microhabitats. Despite lower Δz values per pin measurement, over the study duration, vegetated pins had a net elevation increase of ≈20 cm, whereas transitional and unvegetated microhabitats had much lower change, near-zero net gain. These results support vegetated microhabitats being more stable and having better sediment retention than unvegetated and transitional areas. Comparatively, mesoscale UAS surfaces typically overestimated Δz, such that variation stemming from vegetation across microhabitats was obscured. However, these data highlight larger mesoscale habitat impacts that cannot be determined from point measurements regarding volumetric change and feature mapping. Changes in features, such as beach access paths, that are associated with increased dynamism are quantifiable using mesoscale remote sensing methods rather than microscale methods. Regardless of the metric, maintaining baseline data is critical for assessing what is captured and missed across spatiotemporal scales and is necessary for understanding the contributors to heterogeneous topographic change in sandy coastal foredunes.

Maputo Special Reserve and dung beetle conservation in the heterogeneous landscape of the Maputaland Centre of Endemism

Background: Maputo Special Reserve (MSR) in Mozambique lays within the Maputaland Centre of Endemism (MCE) and protects the biota of a habitat mosaic dominated by coastal dune forest and inland sand forest patches of different sizes surrounded by natural grassland. Objectives: To determine the importance of woody versus grassland vegetation for supporting endemic east coast versus widespread savanna dung beetles in the MCE in the face of increased accessibility and exploitation of woody vegetation in southern Mozambique, especially by charcoal burners.Method: We used general linear mixed models, additive partitioning of diversity and ordination to analyse species abundance and occurrence across a mosaic of three major habitats in the MSR (grassland, sand and dune forest).Results: High compositional heterogeneity was found between habitat types and study sites so that beta diversity was mostly higher than alpha diversity. Three distinct scarabaeine dung beetle assemblages defined from ordination were largely centred on the three habitat types. Out of a total of 61 species, greater numbers were associated with grassland (38) than sand (17) and dune forest (6) although abundance was greater in both dune forest and grassland than in sand forest. Biogeographical classification indicated that >40% of the species are endemic to the east coast of southern Africa with the remainder centred in adjacent savanna. Endemic east coast species were well represented in both forest (15) and grassland (11). Savanna species were better represented in grassland (27) than forest (8). Proportions of grassland species and their abundance declined across increasing patch sizes of sand forest becoming lowest in dune forest.Conclusions: Conservation of endemic, east coast dung beetle species requires the preservation of both natural grassland and sizeable patches of forest in an undisturbed habitat mosaic. As the east coastal system is relatively small in extent with the MCE widely transformed in South Africa, the MSR is an important contributor to regional conservation of endemic species.

Marine heatwaves in the Humboldt current system: from 5-day localized warming to year-long El Niños

During the last 4 decades punctual occurrences of extreme ocean temperatures, known as marine heatwaves (MHWs), have been regularly disrupting the coastal ecosystem of the Peru-Chile eastern boundary upwelling system. In fact, this coastal system and biodiversity hot-spot is regularly impacted by El Niño events, whose variability has been related to the longest and most intense MHWs in the world ocean. However the intensively studied El Niños tend to overshadow the MHWs of shorter duration that are significantly more common in the region. Using sea surface temperature data from 1982 to 2019 we investigate the characteristics and evolution of MHWs, distinguishing events by duration. Results show that long duration MHWs (> 100 days) preferentially affect the coastal domain north of 15° S and have decreased in both occurrence and intensity in the last four decades. On the other hand, shorter events, which represent more than 90% of all the observed MHWs, are more common south of 15° S and show an increase in their thermal impact as well as on the number of affected days, particularly those spanning 30–100 days. We also show that long duration MHWs variability in the coastal domain is well correlated with the remote equatorial variability while the onset of short events (< 10 days) generally goes along with a relaxation of the local coastal wind.

Pricing and Market Results of Greek Coastal System after Cabotage Privilege Removal (2002-2010): The Example of European and Global Aviation

The purpose of this article is to compare Greek coastal shipping and aviation industry immediately after their liberalization. It focuses mainly on fare configuration analysis of domestic and global aviation to compare the conclusions with Greek coastal market. This is an innovative approach as there has been no such research effort on this issue in the past. The importance of our analysis lies to a large extent in exploring the improvement or deterioration of passenger services for the two modes of transport following the lifting of cabotage privilege. It can be a yardstick for those researchers who want to know in advance what could happen in the first years of liberalization in a transport industry. The analysis results show that the institutional framework and the economic market conditions in two industries characterized by both similarities and differences. JEL classification numbers: R40, M21, L50. Keywords: Global and European Aviation, Greek coastal shipping, Market liberalization, Lifting of cabotage privilege, Fares, Passenger service.

Ecological Importance of Alkaline Phosphatase Activity in Changing Marine Environmental Conditions

The effects of changing hydrological and climatic conditions on the dynamics of phosphorus (P) were studied in the Northern Adriatic Sea (NA), a coastal system currently affected by these changes. P limitation is one of the key stresses in the NA and it is a globally important phenomenon in aquatic ecosystems. Therefore, the response to P stress by inducing alkaline phosphatase activity (APA) was studied in characteristic water types in the NA, formed by the changing freshwater input in different thermic conditions. APA was important in providing P for microbial growth in upper waters dominated by assimilation during the warmer part of the year in stratified conditions. Contrarily, APA was not important during mixing in the colder part of the year, as well as in waters dominated by regeneration. In waters influenced by freshwater, temperature had no effect on APA, while in high-salinity waters, temperature was an important factor for APA increase. The highest APA occurred during riverine nutrients supply, indicating that the alteration of anthropogenic nutrient loads might strongly change P status in this coastal system. Furthermore, predicted increases in winter sea temperature and summer Po River discharge could delay the water column mixing, prolonging periods of P limitation.

Seasonal Variations in the Biodiversity, Ecological Strategy, and Specialization of Diatoms and Copepods in a Coastal System With Phaeocystis Blooms: The Key Role of Trait Trade-Offs

Although eutrophication induced by anthropogenic nutrient enrichment is a driver of shifts in community composition and eventually a threat to marine biodiversity, the causes and consequences on ecosystem functioning remain greatly unknown. In this study, by applying a trait-based approach and measuring niche breadth of diatoms and copepods, the drivers and underlying mechanisms of the seasonal species succession of these ecological communities in a coastal system dominated in spring by Phaeocystis blooms were explored. It is suggested that the seasonal succession of diatoms and copepods is the result of several trade-offs among functional traits that are controlled by the seasonal abiotic and biotic pressure encountered by the plankton communities. The results of this study highlight that a trade-off between competition and predator, i.e., weak competitors are better protected against predation, plays an important role in promoting plankton species richness and triggers the Phaeocystis bloom. As often observed in eutrophicated ecosystems, only the biotic homogenization of the copepod community and the shift in the diet of copepods toward Phaeocystis detrital materials have been detected during the Phaeocystis bloom. The diatom and copepod communities respond synchronously to fluctuating resources and biotic conditions by successively selecting species with specific traits. This study confirms the key role of competition and predation in controlling annual plankton succession.