Modelling Beach Litter Accumulation on Mediterranean Coastal Landscapes: An Integrative Framework Using Species Distribution Models

Unravelling the Nexus of Beach Litter and Plant Species and Communities Along the Mediterranean Coasts: A Critical Literature Review

Beach litter, an anthropogenic and hazardous component, can interact with psammophilous plant species and communities. These are particularly prominent in the Mediterranean Basin, renowned for its highly specialized and unique flora but recognized as one of the areas that is globally most severely affected by marine litter. To provide a comprehensive picture and outline possible future directions, data on beach litter in the Mediterranean coastal ecosystems were collected through a bibliographic research. Overall, 103 studies investigated the presence of beach litter on the Mediterranean coasts, of which only 18 considered its relationship with psammophilous plant species and communities. Our research highlights that this topic is rather underexplored in the Mediterranean Basin and the need to develop a standardized protocol for the assessment of beach litter that can be applied consistently across different beaches and countries. Information collected through a standardized protocol might improve the management and conservation strategies for these fragile ecosystems.

Investigating variability among fisheries litter accumulation on beaches in Paraná, Brazil

Fishing activities strongly influence coastal and marine environments and are responsible for generating marine litter. In southern Brazil, there are several artisanal (small-scale) fisher settlements that potentially contribute towards regional marine litter. The present study sought to address the deficit in available information by investigating the in situ contribution of artisanal fishing communities to marine litter on adjacent beaches. During one month in the 2019 austral winter, 200-m stretches of beach were investigated at four locations (three artisanal fishing and one control community) in Paraná state. In total, 2196 items were collected; among which only 104 (<5 %) were fisheries related and these remained partially independent of the presence of the three fishing communities across both small and large spatial scales (i.e., from m to km). Rather than the presence of fishing communities, fisheries-related litter appears to primarily originate from external sources and may regionally accumulate via natural vectors such as oceanic currents.

Understanding through drone image analysis the interactions between geomorphology, vegetation and marine debris along a sandy spit

Marine litter (ML) is recognized as one of the main socio-economic and environmental concerns and monitoring operations have been realized worldwide in order to collect information on the types, quantities and distribution of marine debris. In this study, we used Unmanned Aerial Vehicle (UAV) images to map the presence of ML on a coastal spit in relation to geomorphological aspects and vegetation. Our results show that ML is present everywhere, but concentrates in the beach wrack, dunes, and saltmarshes, highlighting the role of the vegetation in trapping ML. Moreover, ML will most probably remain trapped by the saltmarsh vegetation, since they are not visible and easily accessible to allow cleaning operations. On the contrary, cleaning operations may remove the ML present in the beach wrack. Finally, our results provide useful information to support decision-makers for improving beach cleaning activities in the Po river Delta areas (Italy).

Impact of storms and proximity to entry points on marine litter and wrack accumulation along Mediterranean beaches: Management implications

Beach litter can affect public health and economic activities worldwide forcing local authorities to expensive beach cleaning. Understanding the key mechanisms affecting the accumulation of this waste on beaches, such as sea state and proximity to entry points, is critical to plan effective management strategies. In this one-year study, we estimated the impact of storm events and waterways runoff on litter abundance and local economy using as a model a managed, peri-urban beach facing a north-western sector of the Mediterranean Sea. We also investigated the relationship between litter composition/density and beach proximity to major/closest harbors/rivers at regional scale by combining our data with those on litter density available in literature. Autumn/winter storms caused larger litter depositions than spring/summer ones in the peri-urban beach. No preferential accumulation occurred near to waterway mouths. Litter mainly consisted of plastic, and its composition in terms of micro-categories varied over seasons. In total, 367,070 items were deposited along 4.7 km of beach over one year, and the cost for the removal of this waste amounted to approximately 27,600 euros per km/year. At regional scale, beach litter density was positively correlated to the proximity of major harbors while its composition was related to the proximity to both major harbors and rivers. Results indicate that autumn/winter storms are important drivers of marine litter deposition. They also suggest that beaches in front of the convergence zone of littoral currents and close to major harbors can be particularly subjected to this kind of pollutant. To increase their effectiveness, litter mitigation/cleaning activities should be planned based on predictions of major storm events and performed at spatial scales encompassing at least coastal regional sectors.