An Integrated Coastal Sediment Management Plan: The Example of the Tuscany Region (Italy)

This paper presents the results of a study carried out to support the Region of Tuscany Coastal Sediment Management Plan, with the main aim of establishing the sediment budget considering the time span from 1981-1985 to 2005 for the 56 coastal sectors into which the 215 km-long continental sandy coast of Tuscany (Italy) was divided. The sand stability (according to a stability index) and colour compatibility (according to the CIEL*a*b* colour space with an acceptability range conforming to national guidelines) were determined in order to assess the possibility of using the available sediment in accreting sectors to nourish the beach in eroding areas. Only in two cases-i.e., the updrift of a harbour (at Viareggio) and in a convergence zone (at Marina di Pietrasanta)-are the volumes of sufficient magnitude to support a large nourishment project; however, the mean sand size is too small to guarantee efficient nourishment, even with medium-term stability. In contrast, the colour difference, in most of the cases, was shown to be acceptable. Other small sediment stocks, suitable for colour but not for grain size, can be used for periodic ephemeral nourishment works to support seasonal tourist activities. The limited resources available make it necessary to adopt a plan for their optimal use from a regional perspective. This kind of study is of great interest for the proposal of sound management actions to counteract the increasing erosion processes linked to climate change phenomena and human effects on rivers and coastal systems

An integrated approach to coastal erosion problems in northern Tuscany (Italy): Littoral morphological evolution and cell distribution

Occupation of the coast has significantly increased in recent decades, mostly due to a greater demand for recreation and tourism. Today, erosion threatens many human-made structures and activities, requiring an integrated approach for the understanding of coastal dynamics and identification of alternatives to associated problems. This study investigates a 64 km-long coastal physiographic unit in the northern microtidal littoral of Tuscany (Italy). Vertical aerial photographs and direct field surveys were used to retrieve changes in shoreline position over 1938–1997 and 1997–2005 time intervals. Significant beach accretion was observed during the first period updrift of Carrara (84 m) and Viareggio (280 m) harbours and at Marina di Pietrasanta (100 m), whereas severe erosion occurred downcoast of Carrara harbour (−130 m, at Marina dei Ronchi) and on the northern side of Arno river mouth (−400 m). Similar trends were observed between 1997 and 2005; beach slope between the 1997 shoreline position and the closure depth correlated well with the distribution of erosion/accretion patterns from the 1938–1997 period (slopes were lower in eroded areas than at sites under accretion). Longshore distribution of erosion/accretion patterns was controlled by coastal compartmentalisation. Three of the main littoral cells were mostly formed by natural limits (i.e., Punta Bianca promontory, Marina di Pietrasanta, the Arno river mouth and the port of Livorno). Several sub-cells were created within these cells due to the introduction of human-made structures (such as Carrara and Viareggio harbours), which formed artificial fixed limits that allowed the transport of sediments (exclusively fines) in one direction only. Results will help improve the understanding of coastal processes and manage littoral sediment transport in a sustainable manner. This will reduce the need for structural interventions, such as breakwaters and groynes, which in the past decades prevented coastal retreat at local scale but shifted erosion downdrift, leading to degradation of the investigated area and requiring continuous maintenance

Comments on Marine Litter in Oceans, Seas and Beaches: Characteristics and Impacts.

Marine litter is observed along shorelines, pelagic, benthic marine and lake systems all around the globe. On beaches, litter creates aesthetic and related economic problems because a clean beach is one of the most important characteristics of a seaside resort required by visitors. Litter can reach the marine environment from marine or land activities but it is estimated that 80% originates from land-based sources. The marine-based sources of litter include all types of sea-going vessel and offshore installations, the most abundant plastic debris in the oceans being derelict (lost or improperly discarded) fishing gear. Most of marine litter is composed by plastics due to their greater durability and persistence, combined with plastic rising production and low rates of recovery. Special importance is linked to microplastics because their ubiquity, persistence, mechanical effects on biota and the ecosystem because of ingestion by organisms and their toxic potential. As plastics degrade they can release toxic chemicals initially incorporated during their manufacturing or persistent organic pollutants and heavy metals sorbed to their surfaces in the environment. Such toxins can disrupt endocrine functions and cause harmful reproductive and developmental effects in aquatic animals

Coastal scenic assessment and tourism management in western Cuba

Coastal scenic assessments via checklist tables (18 natural, 8 human related parameters), can provide benchmark measures regarding desirable/non-desirable beach conditions and also classify sites. The scenic value for 43 sites in western Cuba was investigated, with the aim of helping managers improve bathing areas, especially for tourism purposes. Sites were categorised from Class 1, (top grade scenery), between La Habana and Matanzas, as extremely attractive, with white sand, turquoise water and additional scenic elements. Class 2 sites were located in Varadero, and their high scores were greatly due to appropriate human interventions, e.g. beach nourishment and dune restoration works. Classes 3 to 5 (the latter having very poor scenery), included sites with low scores for natural parameters. For these sites, coastal managers can do little to alleviate scenic impact, apart from addressing the human parameters, where improvement is possible, e.g. by litter removal together with the present chaotic protective structures

Morphological cells in the Ragusa littoral (Sicily, Italy)

Geomorphologic information, topographic maps (dated 1967), aerial photographs (dated 1999 and 2008), and spatial analysis procedures were used to investigate a 90 km long coastal sector in South Sicily (Italy). Information was obtained on coastal erosion/accretion areas, general sediment circulation pattern and littoral cell distribution. Human-made structures and natural headlands constituted important artificial limits dividing littoral in morphological cells. Ports and harbours were observed at Scoglitti, Punta Secca, Marina di Ragusa, Donnalucata and Pozzallo. Most of them worked as “transit” limits which interrupted predominant, eastward directed sedimentary transport, this way generating accretion in updrift (west) side of mentioned structures and erosion in downdrift (east) side. During the 1967–2008 period, about 62,000 m2 and 42,000 m2 of beach surface were respectively formed updrift of Scoglitti and Donnalucata ports. The construction of Pozzallo port gave rise to the formation of a “convergent” limit which favoured large accretion (94,000 m2) east of port structure. Most important natural structures were observed at Punta Zafaglione, P. Braccetto and Cava d’Aliga. The knowledge of littoral cell distribution acquires a great importance for appropriate management of coastal erosion processes which may be mitigated installing by-passing systems in ports and harbours and carrying out nourishment works in eroding areas, often located downdrift of ports and harbours (when these structures work as transit limits) and in central part of littoral cells (when these structures work as convergent limits)

On the status and mechanisms of coastal erosion in Marawila Beach, Sri Lanka

Coastal erosion remains a problem in many developing countries because of a limited understating of erosion mechanisms and management. Sri Lanka is one of the countries that recognized coastal erosion management as a governmental responsibility, in 1984. Nevertheless, erosion mechanisms have not yet been fully understood. We investigate the status and mechanisms of coastal erosion using empirically collected data and various techniques, such as Geographic Information System analysis of satellite images, drone mapping, bathymetric surveys, hindcasting of wind-induced wave climate, questionnaires, and semi-structured interview surveys. We identified wave climate change, reduction in river sand supply, interruptions from previous erosion management measures, and offshore sand mining as potential causes of erosion considering sediment flux and rates of erosion. Erosion of Marawila Beach began during 2005–2010 and has been continuing ever since, due to a lack of integration in the beach and the entire sediment system. It is necessary to identify the long-term, large-scale changes in the sediment system through data collection. This study highlights the importance of an integrated coastal erosion management plan and could facilitate better coastal erosion management in Sri Lanka, as well as in other developing countries

Metabolic reprogramming of colorectal cancer cells resistant to 5-FU

Metabolic rearrangements are essential to satisfy the different needs of cancer cells during tumorigenesis. Recent studies highlighted a role for such metabolic reprogramming in adaptation to therapies and chemo-resistance development. 5-fluorouracil (5-FU) is an antimetabolite drug widely used as a first-line treatment for colorectal cancer. Despite several advantages of 5-FU, its clinical application is still greatly limited, due to the acquisition of drug resistance. In the first part of this thesis, we illustrate the role of micro RNAs (miRNAs) in reprogramming colon cancer cells toward a resistant phenotype as well as their involvement in the response of resistant cells to acute treatment with 5-FU. We performed a global gene expression profile for the entire miRNA genome, and we found a change in the expression of four miRNAs following acute treatment with 5-FU in cells resistant to this drug. Among them, we focused on miR-210-3p, previously described as a key regulator of DNA damage repair mechanisms and mitochondrial metabolism. Here we show that miR-210-3p downregulation enables resistant cells to counteract the toxic effect of the drug increasing the expression of RAD-52 protein, involved in DNA damage repair. Moreover, miR-210-3p downregulation enhances mitochondrial oxidative metabolism, increasing the expression levels of succinate dehydrogenase subunits D, decreasing intracellular succinate levels and inhibiting HIF-1α expression. These results suggest that miR-210-3p downregulation following 5-FU treatment sustains DNA damage repair and metabolic adaptation to counteract drug treatment, thus supporting the resistant phenotype. In the second part of this thesis, we reveal important adaptations in serine and one-carbon metabolism associated with the acquisition of 5-FU resistance in colorectal cancer cells. 5-FU resistant cells showed an increase in both serine up-take from extracellular medium and de novo serine synthesis pathway. Together with increased serine availability, dynamic labeling experiment after 13C-serine incubation underlined a different utilization of serine-derived carbons in resistant cells with a sustained flux into the mitochondrial compartment supporting increased purine nucleotides synthesis. Accordingly, we found a strong decrease in the expression of the cytosolic isoform of the enzyme serine hydroxy-methyltransferase (SHMT1) and a concomitant increase in the expression of the mitochondrial isoform (SHMT2) in 5-FU resistant cells compared to parental cells, confirming the shift toward mitochondrial one-carbon branch activity. Accordingly, higher expression levels of the mitochondrial serine transporter SFXN1 have been observed in resistant cells with respect to the sensitive ones. Silencing SHMT2 in 5-FU resistant cells increases the efficacy of the treatment with 5-FU against resistant cells confirming the importance of the reported adaptation in the acquisition of resistance to 5-FU. In conclusion, the data shown in this thesis underline different adaptations related to both miRNAs expression and nutrient metabolism carried out by 5-FU resistant cells. This reprogramming supports the response of 5-FU resistant cells to overcome the toxic effect of the drug. The identification of such alterations opens the possibility of new therapeutic approaches to tackle resistant cells and overcome colon cancer relapse