Dispersion of surface floating plastic marine debris from Indonesian waters using hydrodynamic and trajectory models

Plastic waste has become the most significant component of marine debris, while research on traces of marine plastic waste related to the condition of Indonesian waters is still limited. Therefore, this study examines the movement patterns of plastic marine debris in Indonesian waters. Simulations were carried out for one year (2013) using the HAMburg Shelf Ocean Model (hydrodynamic model) and Lagrange trajectory. The approach treated the simulated particles as conservative particles floating at sea. Even though the percentage is small (±16 %), Indonesia contributes to transboundary marine debris in the Pacific Ocean, Indian Ocean, and the South China Sea due to the influence of the south equatorial currents moving from north and south of Indonesia. Most of the plastic marine debris remains in Indonesian waters (±80-84 %) and moves back and forth due to the influence of the monsoon currents. Therefore, the Java Sea becomes a crossing point and accumulates plastic marine debris.

Sargasso Sea Vibrio bacteria: Underexplored potential pathovars in a perturbed habitat

We fully sequenced the genomes of 16 Vibrio cultivars isolated from eel larvae, plastic marine debris (PMD), the pelagic brown macroalga Sargassum, and seawater samples collected from the Caribbean and Sargasso Seas of the North Atlantic Ocean. Annotation and mapping of these 16 bacterial genome sequences to a PMD-derived Vibrio metagenome-assembled genome created for this study showcased vertebrate pathogen genes closely-related to cholera and non-cholera pathovars. Phenotype testing of cultivars confirmed rapid biofilm formation, hemolytic, and lipophospholytic activities, consistent with pathogenic potential. Our study illustrates that open ocean vibrios represent a heretofore undescribed group of microbes, some representing potential new species, possessing an amalgam of pathogenic and low nutrient acquisition genes, reflecting their pelagic habitat and the substrates and hosts they colonize.

Polymer composition analysis of plastic debris ingested by loggerhead turtles (Caretta caretta) in Southern Tyrrhenian Sea through ATR-FTIR spectroscopy

The ingestion of anthropogenic plastic debris by marine wildlife is widespread in the Mediterranean Sea. The endangered status (in the IUCN Red List) of Loggerhead turtle (Caretta caretta, Linnaeus, 1758) is a consequence of its vulnerability. In this study, macro-/meso-plastics (5-170 mm) collected from faeces of twelve loggerhead turtles rescued (live) in the Aeolian Archipelago (Southern Tyrrhenian Sea, Italy) were analyzed by size, weight, shape, color and polymer type through Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR). The defecation rate during hospitalization (7-14 days) varied among turtles (from 0.08 to 0.58). The mean number of plastic expulsions (2.7 ± 1.8 items for turtle) was higher during the 5th day of hospitalization (Kruskal-Wallis test, P = 0.01). However, the mean number of plastic-like items defecated during the common days of hospitalization did not vary among turtles (Kruskal-Wallis test, P > 0.05). All turtles were found to have ingested plastic. A total of 114 debris items were recovered from their faeces, 113 of which were identified as plastic. Their color was mostly white-transparent (64.9%) and light (19.3%). Shape was mainly fragments (52.6%), sheets (38.6%), followed by nylon, net-fragments, elastic plastic, foamed plastic and industrial granules (8.8%). Meso-plastics (5-25 mm) represented 72% of the total number of debris and were found more frequently in turtle with Curved Carapace Length (CCL) ≤ 60 cm (CCL = 30-60 cm, n = 5) than those with CCL >60 cm (CCL = 60-71 cm, n = 7). Plastic items were composed mainly of polyethylene (48.2%) and polypropylene (34.2%). Polypropylene (R² = 0.95, P < 0.001) and polyisoprene (R² = 0.45, P = 0.017) were more common in meso-plastics while polyethylene (R² = 0.44, P < 0.01) in macro-plastics. Finally, high-density polyethylene, polyvinyl chloride, polyamide and polyurethane were also found in some turtles. This study reveals high spreads of plastic contamination in faeces of both turtles with CCL ≤60 cm and CCL >60 cm, particularly vulnerable to the increasing quantity of floating plastic into their foraging sites highlighting the need of further research to associate debris ingestion with turtle diet and their size.

Marine plastic litter in certain trawl grounds along the peninsular coasts of India

Non-biodegradable marine debris such as derelict fishing gears and their parts, polythene covers, carry bags, synthetic packaging materials etc., cause serious damages to the benthic ecosystem including the marine biota. We report here the monthly variation in the marine plastic litter (MPL) and its relative percentage to the quantity of fish caught from the trawling grounds off Cochin, Ratnagiri, Mumbai and Veraval along the west coast as well as Visakhapatnam from the east coast of India. The mean values of MPL from the fishing grounds registered the maximum of 55.2 ± 16.52 kg/km² off Veraval and the minimum of 2.11 ± 0.55 kg/km² off Visakhapatnam, registering a national average of 10.95 ± 3.05 kg/km². The relative percentage of MPL over the fish catch remained highest (3.83%) at Veraval and lowest from Visakhapatnam (0.33%) while, the national average was 1.89 ± 0.28. Monsoon season registered maximum MPL in the fishing grounds of all the coastal regions we studied. Depth of the trawling grounds also influenced the quantity of MPL that 20 m depth registered quantity (24.25 ± 9.16 kg/km²) and the overall mean at 10 m and 40 m depth zone are significantly different from that of 20 m. The database created through this study are discussed in the light of increasing deleterious effects of plastic pollution in the active fishing areas in coastal region and the urgent need to save the sea for sustainable use of its resources.

Estimation of plastic marine debris volumes on beaches using unmanned aerial vehicles and image processing based on deep learning

Plastic marine debris (PMD) is of global concern. To help address this problem, a novel approach for estimating PMD volumes using a combination of unmanned aerial vehicle (UAV) surveys and image processing based on deep learning is proposed. A three-dimensional model and orthoscopic image of a beach, constructed via Structure from Motion software using UAV-derived data, enabled PMD volumes to be computed by edge detection through image processing. The accuracy of the method was verified by estimating the volumes of test debris placed on a beach in known sizes and shapes. The proposed approach shows potential for estimating PMD volumes with an error of <5%. Compared with subjective methods based on beach surveys, this approach can accurately, rapidly, and objectively calculate the PMD volume on a beach and can be used to improve the efficiency of beach surveys and identify beaches that need preferential cleaning.

Plastic cigar tips debris: Exploring use and disposal issues for Lake Erie beaches

Great Lakes states are increasingly faced with questions regarding how plastic debris is impacting marine and coastal ecosystems. This is especially evident along the southern beaches of Lake Erie, where high population and industrial development have contributed to the plastics problem. In Ohio, the most common items found are cigarettes and other smoking related materials, including plastic cigar tips. Given the growing awareness of the issue, and the impact of plastics on beaches throughout the Great Lakes, a focus group convened to investigate strategies to help address the problem. The group was comprised of individuals with practical knowledge of plastic cigar tip use and disposal issues, including representatives of government agencies, nongovernmental organizations, community groups, and local academic institutions. This report represents the exploratory results of the focus group, complete with information regarding the what, why, and how of plastic cigar tip debris in the region, guidance on the material and social barriers to sustaining desired behaviors (cessation of use by minors and/or proper disposal), strategies to overcome those barriers, and suggestions for management and policy actions moving forward. Group members suggest that a combination of education and government-supported financial incentives may be the most effective approach, with community-based positive messaging backed by local taxes on smoking items that have plastic tips and rebates or other rewards for properly disposing of debris.

Microplastic-associated bacterial assemblages in the intertidal zone of the Yangtze Estuary

Plastic trash is common in oceans. Terrestrial and marine ecosystem interactions occur in the intertidal zone where accumulation of plastic frequently occurs. However, knowledge of the plastic-associated microbial community (the plastisphere) in the intertidal zone is scanty. We used high-throughput sequencing to profile the bacterial communities attached to microplastic samples from intertidal locations around the Yangtze estuary in China. The structure and composition of plastisphere communities varied significantly among the locations. We found the taxonomic composition on microplastic samples was related to their sedimentary and aquatic origins. Correlation network analysis was used to identify keystone bacterial genera (e.g. Rhodobacterales, Sphingomonadales and Rhizobiales), which represented important microbial associations within the plastisphere community. Other species (i.e. potential pathogens) were considered as hitchhikers in the plastic attached microbial communities. Metabolic pathway analysis suggested adaptations of these bacterial assemblages to the plastic surface-colonization lifestyle. These adaptations included reduced "cell motility" and greater "xenobiotics biodegradation and metabolism." The findings illustrate the diverse microbial assemblages that occur on microplastic and increase our understanding of plastisphere ecology.

Aquaculture and urban marine structures facilitate native and non-indigenous species transfer through generation and accumulation of marine debris

Both the invasion of non-indigenous marine species (NIMS) and the generation and accumulation of anthropogenic marine debris (AMD) are pervasive problems in coastal urban ecosystems. The biosecurity risks associated with AMD rafting NIMS have been described, but the role of aquaculture derived AMD has not yet been investigated as a biosecurity vector and pathway. This preliminary study targeted 27 beaches along the Coromandel Peninsula, New Zealand, collecting debris from belt transects. Plastic (specifically plastic rope) was the dominant AMD present on beaches. The most common biofouling taxa were hydroids, bryozoans, algae and polychaetes, with one NIMS pest species, Sabella spallanzanii, detected fouling plastic rope. Our findings demonstrate that aquaculture is an AMD (plastic rope) generating activity that creates biosecurity risk by enhancing the spread of NIMS. The rafting of S. spallanzanii on AMD generated at aquaculture facilities is currently an unmanaged pathway within New Zealand that needs attention.