Relationships between size and abundance in beach plastics: A power-law approach

Sandy beaches are one of the most relevant coastal environments in terms of socio-ecological and economical value. So, the presence and accumulation of plastic litter determines a degradation of these values, and calls for management actions for cleaning are required. In this research, we investigated the features of plastic litter distribution on a Mediterranean beach in relation to size and abundance of the sampled items. Simple allometric models were applied with the aim to provide a parsimonious tool for estimating the amount and sizes of the beach plastic litter. The results show effective relations between size and abundance of plastic items according to the power-law distribution. This relationship could support decision-makers to estimate the total amount of beach plastics through the application of a simple model instead of more complex models requiring the estimation of many parameters and the availability of large datasets

Between a rock and a hard place: Environmental and engineering considerations when designing coastal defence structures

Coastal defence structures are proliferating as a result of rising sea levels and stormier seas. With the realisation that most coastal infrastructure cannot be lost or removed, research is required into ways that coastal defence structures can be built to meet engineering requirements, whilst also providing relevant ecosystem services—so-called ecological engineering. This approach requires an understanding of the types of assemblages and their functional roles that are desirable and feasible in these novel ecosystems. We review the major impacts coastal defence structures have on surrounding environments and recent experiments informing building coastal defences in a more ecologically sustainable manner. We summarise research carried out during the THESEUS project (2009–2014) which optimised the design of coastal defence structures with the aim to conserve or restore native species diversity. Native biodiversity could be manipulated on defence structures through various interventions: we created artificial rock pools, pits and crevices on breakwaters; we deployed a precast habitat enhancement unit in a coastal defence scheme; we tested the use of a mixture of stone sizes in gabion baskets; and we gardened native habitat-forming species, such as threatened canopy-forming algae on coastal defence structures. Finally, we outline guidelines and recommendations to provide multiple ecosystem services while maintaining engineering efficacy. This work demonstrated that simple enhancement methods can be cost-effective measures to manage local biodiversity. Care is required, however, in the wholesale implementation of these recommendations without full consideration of the desired effects and overall management goals

Best practices, good practices and guidelines: a critical review based on different management options in protected areas of cross-boundary Adriatic-Ionian region

Best practices are, by definition, the best ways to reach a specific goal. In the environmental field, best practices are experiences and quality projects carried out in the territory, by institutions, companies or citizens, that produce benefits in different environmental sectors applied to solve a concrete problem. Relevant features of best practices are their validation and replicability in time and space. In the context of the EU Co-funded BIG (Improve governance, management and sustainable valorization of coastal and rural protected areas and contributing to the implementation of the Natura 2000 provisions in Greece and Italy) best practices have been collected through a web search and questionnaires submitted to the managers of the protected areas to build a reference database/atlas. The database critical analysis has highlighted some gaps about the effective presence and applicability of these best practices. Moreover, their effectiveness has been analyzed on the base of the specific characteristics of the Italian and Greek areas involved in the BIG project. Some contrasting problems to the best practice definition have been highlighted

Global patterns in sandy beach erosion: unraveling the roles of anthropogenic, climatic and morphodynamic factors.

Beach erosion is a complex process influenced by multiple factors operating at different spatial scales. Local (e.g., waves, tides, grain size, beach width and coastal development) and regional (e.g., sea level rise and mean sea level pressure) factors both shape erosion processes. A comprehensive understanding of how these drivers collectively impact sandy beach erosion is needed. To address this on a global-scale we assembled a database with in-situ information on key physical variables from 315 sandy beaches covering a wide morphodynamic range and complemented by satellite data on regional variables. Our results revealed the combined influence of local and regional factors on beach erosion rates. Primary drivers were regional anomalies in mean sea level pressure and variations in mean sea level, and local factors such as tide range, beach slope and width, and Dean's parameter. By analyzing morphodynamic characteristics, we identified five distinct clusters of sandy beaches ranging from wave-dominated microtidal reflective beaches to tide-modified ultradissipative beaches. This energy dissipation gradient emerged as a critical factor, with erosion rates increasing with beach width and dissipativeness. Our study also highlighted the tangible impact of climate change on beach erosion patterns. Hotspots were identified, where intensification of regional anomalies in mean sea level pressure, increasing onshore winds and warming rates, and rising sea levels synergistically accelerated erosion rates. However, local variables were found to either amplify the effects of regional factors on erosion or enhance a beach's resistance, mitigating erosive trends initiated by regional drivers. Our analysis showed that more than one-fifth of the analyzed beaches are experiencing intense, extreme, or severe erosion rates, and highlighted the significant role of human activities in explaining erosion trends, particularly in microtidal reflective and intermediate beaches. This underscores the long-term threat of coastal squeeze faced by sandy beaches worldwide and emphasizes the need to consider both local and regional drivers in order to understand erosion processes. Integrating localized measurements with broader satellite observations is required for a comprehensive understanding of the main drivers behind coastal evolution, which in turn is needed to manage and preserve these fragile ecosystems that are at ris

Chapter 7. Case studies worldwide. Section 7.6 Risk Assessment and Mitigation in a Low-lying Coastal Area: Cesenatico, Northern Italy

The Emilia Romagna littoral is located in the northeast of Italy and comprises 130 km of low and sandy coast, most of which are strongly urbanized. The Emilia Romagna beaches face the Northern Adriatic Sea, a relatively shallow epi-continental shelf with low tidal amplitude. A general erosive tendency is mainly caused by the reduced sediment transport rates of the rivers and by the increased anthropogenic subsidence. Subsidence, eustatism, and erosion of dunes pose a serious threat for coastal flooding. Cesenatico municipality is included in the province of Forl\u131`-Cesena. The site is famous for its marina and is a well-known tourist resort with a sandy beach rich in bathing facilities

Shifting sands? Coastal protection by sand banks, beaches and dunes

In a closely integrated system, (sub-) littoral sandy sediments, sandy beaches, and sand dunes offer natural coastal protection for a host of environmentally and economically important areas and activities inland. Flooding and coastal erosion pose a serious threat to these environments, a situation likely to be exacerbated by factors associatedwith climate change. Despite their importance, these sandy ‘soft’ defences have been lost from many European coasts through the proliferation of coastal development and associated hard-engineering and face further losses due to sea-level rise, subsidence, storm surge events, and coastal squeeze. As part of the EU-funded THESEUS project we investigated the critical drivers that determine the persistence and maintenance of sandy coastal habitats around Europe's coastline, taking particular interest in their close link with the biological communities that inhabit them. The successful management of sandy beaches to restore and sustain sand budgets (e.g. via nourishment), depends on the kind of mitigation undertaken, local beach characteristics, and on the source of ‘borrowed’ sediment. We found that inter-tidal invertebrates were good indicators of changes linked to different mitigation options. For sand dunes, field observations and manipulative experiments investigated different approaches to create new dune systems, in addition to measures employed to improve dune stabilisation. THESEUS provides a ‘toolbox’ of management strategies to aid the management, restoration, and creation of sandy habitats along our coastlines, butwe note that futuremanagementmust consider the connectivity of sub-littoral and supra-littoral sandy habitats in order to use this natural shoreline defence more effectivel

C.: Shifting sands? Coastal protection by sand banks, beaches and dunes

In a closely integrated system, (sub-) littoral sandy sediments, sandy beaches, and sand dunes offer natural coastal protection for a host of environmentally and economically important areas and activities inland. Flooding and coastal erosion pose a serious threat to these environments, a situation likely to be exacerbated by factors associated with climate change. Despite their importance, these sandy 'soft' defences have been lost from many European coasts through the proliferation of coastal development and associated hard-engineering and face further losses due to sea-level rise, subsidence, storm surge events, and coastal squeeze. As part of the EU-funded THESEUS project we investigated the critical drivers that determine the persistence and maintenance of sandy coastal habitats around Europe's coastline, taking particular interest in their close link with the biological communities that inhabit them. The successful management of sandy beaches to restore and sustain sand budgets (e.g. via nourishment), depends on the kind of mitigation undertaken, local beach characteristics, and on the source of 'borrowed' sediment. We found that inter-tidal invertebrates were good indicators of changes linked to different mitigation options. For sand dunes, field observations and manipulative experiments investigated different approaches to create new dune systems, in addition to measures employed to improve dune stabilisation. THESEUS provides a 'toolbox' of management strategies to aid the management, restoration, and creation of sandy habitats along our coastlines, but we note that future management must consider the connectivity of sub-littoral and supra-littoral sandy habitats in order to use this natural shoreline defence more effectively

Between a rock and a hard place: Environmental and engineering considerations when designing coastal defence structures

Coastal defence structures are proliferating as a result of rising sea levels and stormier seas.With the realisation that most coastal infrastructure cannot be lost or removed, research is required into ways that coastal defence structures can be built to meet engineering requirements, whilst also providing relevant ecosystem services\u2014 so-called ecological engineering. This approach requires an understanding of the types of assemblages and their functional roles that are desirable and feasible in these novel ecosystems. We review the major impacts coastal defence structures have on surrounding environments and recent experiments informing building coastal defences in a more ecologically sustainable manner. We summarise research carried out during the THESEUS project (2009\u20132014) which optimised the design of coastal defence structures with the aim to conserve or restore native species diversity. Native biodiversity could be manipulated on defence structures through various interventions: we created artificial rock pools, pits and crevices on breakwaters; we deployed a precast habitat enhancement unit in a coastal defence scheme; we tested the use of a mixture of stone sizes in gabion baskets; and we gardened native habitat-forming species, such as threatened canopy-forming algae on coastal defence structures. Finally, we outline guidelines and recommendations to provide multiple ecosystem services while maintaining engineering efficacy. This work demonstrated that simple enhancement methods can be costeffective measures to manage local biodiversity. Care is required, however, in the wholesale implementation of these recommendations without full consideration of the desired effects and overall management goals