General:
Reducing the impact of marine litter
Specific:
This activity is divided into 4 actions:
4.1. Analysis of the in situ characterisation of marine litter collected (typology).
4.2. Analysis of marine litter extraction areas (density and location).
4.3. Studies of valorization of the collected materials and search for final application.
4.4. Ecotoxicological tests of marine litter and its products.
4.5. Transfer of results and dissemination of the project. 4.6. Project coordination and management.
This project reflects the feasibility of reducing the amount of marine litter and its impact, demonstrating the possibility of adequate treatment and recovery of the waste collected, through mechanical recycling technology. The most innovative aspect of the project was the incorporation of chemical recycling technology through plastic waste recovery tests through pyrolysis treatment that allowed different differentiated fractions of great industrial interest to be obtained.
To this end, several working groups were organized to determine the waste collection methodology in each of the brotherhoods participating in the project: Gandía (Valencian Community), Vigo – Marín (Galicia) and La Restinga (Canary Islands). On the other hand, an action protocol was created with the main actions so that other interested brotherhoods can implement this model.
During the previous experiences of RepescaPlas (2018) and Repesca_Plas 2 (2019), the systems for the removal of marine litter by vessels, its storage on the vessel, its operation within the port facilities, and temporary storage until the authorised manager takes charge of the waste to carry out its correct management and treatment, were defined. In this third phase, nine trawlers from the ports of Marín, Bueu and Vigo participated in the collection and deposit in ports of Galicia and 2,699 kg of waste were received in the port of Marín. As they were larger vessels, the waste was stored in 1 m³ “Big-Bag” type bags. In the port of Gandía, 11 trawlers and trammel boats participated. As they were smaller boats, waste bags similar to those used for household waste were used. During 2020, 834.45 kg of deep-bottom waste were removed and characterized by trawlers and 7.47 kg of floating marine litter removed and characterized by trammel boats. In the port of La Restinga (El Hierro), 12 boats belonging to the brotherhood of Nuestra Señora de los Reyes participated. In total, 676.70 kg of marine litter were collected, labelled and classified.
The characterization of the waste was carried out using the MARNOBA platform. This methodology differentiates between marine litter removed from the bottom by means of trawlers (ports of Marín and Gandía) and floating litter removed by small gear vessels (trammel net) in the port of Gandía and artisanal fishing in La Restinga. In the case of trawlers, eight categories (plastic, paper-cardboard, wood, metal, glass, hygienic-sanitary waste, medical waste and others) and 54 types of objects are considered, while in the case of vessels that remove floating garbage by means of small gears, five categories are considered (plastic; paper-cardboard; wood; metal; others) and 35 types of objects for boats. In total, the following 8,474 wastes were contributed to the official marine litter monitoring programme, APP MARNOBA, and characterised by type (1,466 wastes from trawlers in Galicia, 6,193 wastes from trawlers and 767 from small-gear vessels in the port of Gandía in Valencia and 4.9wastes from small-gear vessels in the port of La Restraina on the Island of El Hierro). The main results obtained follow the trend of what was observed in previous projects with regard to the main plastic materials found: Low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polyamide (PA).
The subsequent analysis of the characterization concludes that the appearance of similar objects has been observed in the different demarcations. In the case of Marín (North Atlantic), the main object found comes from fishing sources, while in Gandía (Levantine-Balearic) it comes from domestic sources. In the case of floating garbage, in Gandía the main object found is the same as in the case of dragging, that is, plastic bags, predominantly those for domestic use. On the other hand, in La Restinga (Canary Islands demarcation) fishing sources predominate over industrial or domestic sources.
On the other hand, in order to know the sustainable market viability of at least one plastic fraction studied according to nature, a valorization study of the collected materials was carried out looking for possible final applications. These tests were carried out in AIMPLAS’ pilot plants and, as a last step, in CM PLASTIK’s facilities to obtain the marketable final product. The effort has focused on the flow of polyolefins, i.e. polyethylene and polypropylene. The test results are as follows:
In addition, the University of Vigo carried out toxicity bioassays on two marine species, the sea urchin (Paracentrotus llividus) and copepods (Acartia clausi), with three PVC-based materials and a new product obtained from pyrolysis tests, obtained from those collected by fishing entities. Likewise, the ecotoxicological analysis of the materials considered “problematic” has continued, due to the additives or compounds used for their composition.
For the dissemination of the project, there has been participation by all the partners in different events, both face-to-face and online.
REPESCA_PLAS 3 - Material recovery of plastic waste recovered from the sea: Protocol for sampling, toxicology and design of recovery of marine litter