Residuos en el mar Balear

En prens

Microplastic ingestion in commercial fish species Boops boops, sardine Pilchardus and Engraulis encrasicolus in the western Mediterranean sea: MEDIAS SURVEY

Microplastic ingestion was assessed for three commercial fish species in the western Mediterranean Sea: Boops boops, Sardina pilchardus and Engraulis encrasicolus during the 2015 Spanish MEDIAS survey. Gastrointestinal tracts of 183 fish from 16 sites were examined. A total of 42 microplastics were found in the stomach contents of 31 individuals from all three species. B. boops was found to have ingested the most items (27%). No significant differences between abundance of ingested microplastics and spatial distribution of the sites were found, although it does appears microplastics are common in the food web of each species along the eastern coast of Spain

Spatial distribution of macro- and micro-litter items along rocky and sandy beaches of a Marine Protected Area in the western Mediterranean Sea

In this study, the spatial distribution and physical characteristics of beach macro- and micro-litter within the Cabrera Archipelago Maritime-Terrestrial National Park (Cabrera MPA), in the Balearic Islands have been analysed. For macro-litter items, a mean concentration of 1.9 ± 2.4 items/m2 weighing a total of 13 kg was quantified. In terms of beach composition, cobble beaches with deposited seagrass had almost twice as much marine litter as other beaches. For beach micro-litter items, white and transparent microplastics within the size class of 1–2 mm were the most abundant on all the beaches, and the most common polymer types were polyethylene (64%) and polypropylene (17.2%). Overall, for both macro- and micro-litter items, plastic was the most dominant material (90%) identified on all beaches surveyed within Cabrera MPA, indicating areas of low anthropogenic pressures are increasingly becoming sinks for marine litter.En prens

Assessing spatial and temporal distributions of marine litter: 11-year dataset of coastal floating marine debris in the Balearic Islands

The present work constitutes a preliminary assessment of the spatial and temporal distribution of floating marine debris along the Balearic Islands’ coastline during the months of May - October from 2005 to 2015. This long-term dataset indicates marine debris was found in 42.46% of all monitoring surveys, with plastic marine debris being found in 93.41% of the marine debris surveyed. Elevated accumulation zones were present in the southern regions and plastic was consistently the most abundant for both nearshore and offshore coastal areas. This study provides insight into the magnitude of marine debris surrounding the Balearic Islands highlighting the need for action and awareness to address its increasing pressures on marine and coastal ecosystems

Are the seafloors of marine protected areas sinks for marine litter? Composition and spatial distribution in Cabrera National Park

The seafloors of oceans and seas are becoming major sinks for marine litter (ML) at a global scale and especially within the Mediterranean Sea. Within global oceans and seas, Marine Protected Areas (MPAs) have been established to protect and conserve marine habitats and increase marine biodiversity. In this study, extensive coastal shallow scuba diving surveys were conducted in 2019 and 2020 to identify the distribution of ML in the MPA of Cabrera Marine-Terrestrial National Park (Cabrera MPA) in the Balearic Islands. Approximately 900 items weighing 70.1 kg were collected throughout the MPA during the underwater surveys. Glass bottles, including pieces (25–30%) and glass or ceramic fragments >2.5 cm (8–19%) were the most common identified items followed by plastic food containers and plastic bags (~8%). Overall, 75% of the abundance of collected ML was observed during the first year. In terms of the protection status of the different locations, similar abundances of ML were found in public access areas and no-take areas. Additionally, no significant differences were identified according to location indicating that ML on the seafloor was homogeneous within the studied shallow coastal areas. Overall, the results indicate that Cabrera MPA is a hotspot for ML and mitigation actions and measures, such as annual cleaning efforts, can help to prevent and minimize ML accumulation on the seafloor.En prens

Anthropogenic particles in the zooplankton aggregation layer and ingestion in fish species along the Catalan continental shelf

In this study, we examine anthropogenic particles (APs) in the zooplankton aggregation layer and in fish species along the continental Catalan shelf. APs in the zooplankton aggregation layer were found in 100% of the net tows. Fibres of textile origin dominated the types of AP found in the zooplankton aggregation layer (96%). APs were found ingested in all species of fish at each sampling site, with an overall ingestion occurrence of 21%, with the most abundant fragments (62%). Significant differences in ingestion occurrence were found between species and hierarchal cluster analysis identified two feeding groups, S. pilchardus, T. trachurus and P. erythrinus almost exclusively ingested fibres while T. mediterraneus, S. colias and S. cantharus almost exclusively ingested fragments. The results indicate that the ingestion of APs in the first group of species occurs through indirect ingestion, whereas, in contrast, the second group is composed of more predatory and selective feeders, possibly through accidental predation. In general, our findings indicate that the fate of APs in fish on the Catalan continental shelf depends on the combination of feeding ecology and the availability of APs in the water column.En prens

Distribution and composition patterns of plastic pollution in small islands subjected to different human pressures along the highly connected waters of the NW Mediterranean Sea.

One of the tools to protect Mediterranean biodiversity was the creation of an extensive network of Marine Protected Areas. That those areas are not exempt from plastic pollution has extensively been demonstrated whether they are characterized by a specific plastic composition if compared to not protected areas is currently a topic of discussion. This research aims to evaluate plastic spatial distribution and composition patterns along the surface waters of small islands of the Western Mediterranean Basin subjected to different human pressures and protection status. We studied the spatial distribution of floating plastics by performing 65 surface trawls, carried out using a Hydro-bios manta net coupled with a 335-μm mesh, along the coastal waters of a remote protected archipelago, Columbretes Islands (NW Mediterranean Sea), a protected archipelago located in a high anthropized environment, Cabrera MPA (Balearic Sea), and protected and unprotected areas of two touristic Islands, Mallorca and Menorca in the Balearic Sea. 10637 plastics were identified along the study area and a subset was categorized according to shape, size and polymer. Plastics were found at each sampling site and in all samples. No microscale nor mesoscale variability in plastics abundance was encountered throughout the study area where similar values were found in remote protected areas with no local land-based contamination sources [0.04 (±0.03) items/m2] and in anthropized areas [0.04 (±0.07) items/m2]. Results suggest that floating plastics, in a region such as the NW Mediterranean Sea, strongly exposed to human stressors and highly connected waters, are homogeneously distributed regardless of land uses. Differences were found in plastic size, shape, and polymer composition. Remote islands showed the highest number of fragments reaching percentages higher than 90%, the lowest percentage of film summing up to less than 3%, a lower microscale variability, and the presence of small items with sizes ranging from 2900 μm to 163000 μm not detected in the more anthropized areas. The percentage of film and plastic size increase according to the level of human pressure. Small fragments are the product of fragmentation processes, driven by photooxidation, of larger plastics to smaller ones. Films, due to their volume/surface ratio are suitable for biofouling favoring their faster removal from the sea surface to the seafloor. The lower abundance of film observed in the studied remote protected areas combined with a consistent abundance of small fragments suggest that plastics detected within these waters could be more aged and be arriving from distant sources when compared to plastics detected in more anthropized areas, such as of the Balearic Archipelago, closer to potential marine debris sources and previously described as plastics “retention area”. Remote areas showed a different polymer composition, with a higher percentage of polystyrene, extensively used in the fishing industry that could represent an important contamination source for those areas. Finally, data from this research can contribute to consolidating scientific evidence available for the elaboration and monitoring of future management plans focused on the mitigation and prevention of plastic pollution in marine protected areas