First marine litter assessment in Gibraltar: low-cost and easy to replicate methodology

• Ano de defesa: 2024
• Autor(a) principal: Cerqueira, Paolla Duarte
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Link de acesso: https://app.uff.br/riuff/handle/1/35188

The UN General Assembly recognized marine litter as a global problem in 2001. Marine litter can be defined as “any persistent, manufactured or processed solid material that is discarded, disposed of, abandoned or lost in the marine environment (MSFD, 2008). It is estimated that more than 150 million tonnes of plastics have accumulated in the world's oceans, while 4.6-12.7 million tonnes (Jambeck et al., 2015) are added every year. Marine litter causes harm to the environment, to the fauna, to the economy and even to human health. Yet, there is still much speculation among researchers, policymakers and planners about how to tackle marine litter. Monitoring marine litter is fundamental to better understanding and developing ways to mitigate marine litter. There are marine litter mitigating initiatives that the European governments are committed to, such as the MSFD protocol, which provides a guideline to standardise marine litter assessment. Standardisation is also necessary for the expression of results, allowing the results to be compared and repeated. Most marine litter assessments reviewed were studies done in Europe, specifically in the Mediterranean, although it is important to stress that the literature review was Only conducted in English. The average litter abundance in all studies was 0.74 items per square metre. Gibraltar is a British Overseas Territory located bordering the south of Spain, having coastline in the Bay of Gibraltar and in the Mediterranean. It is a small population península that has a lack of studies and science about it. To conduct the first marine litter assessment in Gibraltar, a low-cost and easy-to-replicate method was used, with the use of snorkelling equipment and footage capture (action camera). Developing this accessible method to standardise marine litter assessments and provide a baseline marine litter abundance and characterisation data for the sites assessed All of Gibraltar’s seven beaches were assessed, resulting in an abundance average of 0,00028 items per square metre, ranking Gibraltar as having the cleanest marine environment in all studies reviewed. There was a significant difference between the abundances of the Bay of Gibraltar and the Mediterranean beaches, respectively with averages of 0.18 and 0.02 items per square metre. The reason for this might be related to the proximity of anthropogenic sources of litter. A finding that supports this hypothesis is that the Western beach is the most polluted beach, as well as the closest one to the Spanish border, where many anthropogenic interventions generate litter. The cleanest beach of Gibraltar was Camp Bay. Plastics corresponded to 72.6% of all items recorded, and most of them were located on the intertidal sand (63.7%). To mitigate marine litter and its impacts in Gibraltar, some actions can be taken, such as raising awareness of the cause, continuing the historic ban of single-use plastics, reinforcing the current ban policies, adding or relocating litter bins to facilitate access to it, expanding marine Science education for outside the schools, creating projects such as marine citizen science, offering adequate disposal location to the dispose of construction litter, and the implementation of frequent marine litter monitoring to better understand its sources in order to address them for a more effective strategy.