In this post, I will cover Corbau et al.’s (2022) article entitled “What can beach litter tell about local management: A comparison of five pocket beaches of the North Sardinia island (Italy)”. The article posits that the type of litter and its distribution are indicative of what kind of local management there is and its efficacy. The study is based on analyses of marine litter collected from 2017 to 2019. Each of the five beaches studied has different anthropogenic and geomorphological features. In this post, I highlight findings on the influence of tourism activity in contributing to marine litter at the sites.
Corbau et al. (2022) define marine litter by the United Nations Environment Program definition: “marine litter is any persistent, manufactured or processed solid material discarded, disposed or abandoned in the marine and coastal environment” (pg. 1).
The cleanliness of each beach was measured by the Clean Coast Index (CCI) by Alkalay et al. (2007):
CCI = (Total litter on transect/total area of transect) × K, where K (coefficient) = 20.
- Very clean: CCI = 0-2
- Clean: CCI = 2-5
- Moderate: CCI = 5-10
- Dirty: CCI = 10-20
- Very dirty: CCI ≥ 20
CCI data collected showed that marine litter was heterogeneously distributed between the different surveys and sites, in terms of the number of litter items collected.
The collected data was generalised in the following figure, which shows the most prevalent types of litter (plastics) and the total number of debris items found:
The presence of tourism at each of the five beach sites was a crucial factor considered in the analyses of the collected data on the types and distribution of litter. Three were very popular tourist destinations and two are heavily regulated for ecological protective measures, though each beach had different specific regulations for tourist activity. These differences allowed for interesting insights into the role of tourism in contributing to marine litter at the Italian beaches. For example, the frequent presence of lolly sticks across all surveys indicates that lolly sticks are not a specific ‘tourist item’, unlike ice cream sticks and chip forks which were absent in the beaches with low/no tourist activity. With this knowledge, Corbau et al. (2022) came to the conclusion that “tourism is not the main cause of marine debris accumulation” (pg. 4).
These tourism-related findings were interesting to me because of how straightforward yet insightful the method of deduction was. That said, one critique I have about this tourism analysis is that it was not made explicit why the different types of trash were considered “tourist items” or not. Though I did understand in the end, this part should be better explained in relation to the various levels of tourism regulation at the different beach sites.
Geomorphology also influences the spatial distribution of marine litter. For example, dunes and hilly morphology bordering landward of one beach meant that deposition and accumulation of debris would occur on the backshore instead. On the other hand, flatter morphology allows for marine debris to be transported and accumulated further inland.
Lastly, efficient beach management measures lead to low CCI i.e. a cleaner beach. This includes the prompt removal of litter, campaigns to inform beach goers of the damaging impacts of marine litter, and sufficient facilities for garbage disposal.
This article by Corbau et al. (2022) thus gives insight into how litter enters the sea from geomorphologically different beaches with different management measures. The article also examines how beaches may be affected by marine litter that has been transported from elsewhere.
References:
Corbau, C., Lazarou, A., Gazale, V., Nardin, W., Simeoni, U., & Carboni, D. (2022). What can beach litter tell about local management: A comparison of five pocket beaches of the North Sardinia island (Italy). Marine Pollution Bulletin, 174, 1–5. https://doi.org/10.1016/j.marpolbul.2021.113170
