The impact of macroplastic debris (>5 mm) on marine life is a global concern but has rarely been investigated in Thailand. This study investigated the relationship between stranded sea turtles and macroplastics in the Central Gulf of Thailand. Records of stranded turtles (n = 388) from 2017-2020 were analysed retrospectively to determine their interaction with macroplastics. In addition, macroplastics collected from the gastrointestinal (GI) tracts of 30 dead stranded turtles and 13 beaches (along a 100 m transect mid-way between high and low tide) between 2019 and 2020 were investigated. Types and composition of macroplastics were identified with the use of a stereomicroscope and Fourier-transform infrared spectrometer. Green turtles Chelonia mydas comprised the majority of stranded turtles (74%, n = 251), and macroplastics (entanglement or ingestion) were the leading cause of death (n = 152). Most stranded turtles were juveniles (65%), and their stranding was significantly correlated with macroplastics (p < 0.001). Juveniles were more prone than adults to become entangled (p = 0.007), while adults had a higher ingestion rate than juveniles (p = 0.009). Plastic fibres were commonly found in the GI tracts (62%, n = 152 of 244) and beaches (64%, n = 74 of 115). Most fibres from the GI tracts (83%, n = 126 of 152) and beaches (93%, n = 68 of 74) were fishing nets made of polyethylene or polypropylene. We conclude that fishing nets are a significant cause of sea turtle stranding in the Central Gulf of Thailand, and this issue requires immediate resolution.

Piper betle L. leaves have traditionally been used to treat various infectious diseases and to possess a wide spectrum of pharmacological effects. This study aimed to determine the antibacterial activity of the Piper betle leaf extract against antibiotic resistant Salmonella spp. isolated from pig farms located in Southern Thailand. Of this, 12 Salmonella spp. isolates were isolated from 24 pig fecal samples from 24 pig farms. The isolates were resistant to ampicillin (91.67%), penicillin (91.67%), tetracycline (81.81%), and doxycycline (81.81%). Antibacterial activity of the Piper betle ethanolic leaf extract against Salmonella spp. was carried out by disc diffusion assays, followed by Minimal inhibitory concentration (MIC) and Minimal bactericidal concentration (MBC) determination, as well as Time kill study. Piper betle extract exhibited antibacterial activity against all the isolates and S. Typhimurium with the inhibition zone ranged from 15.11 ± 0.34 to 20.30 ± 0.50 mm as observed by disc diffusion assay. The extract showed bactericidal activity against the isolates with the MIC and MBC values ranging from 0.5-1.0 mg/mL. Furthermore, the extract at 4 × MIC showed the killing activity with the reduction of the pathogen at least 3 logs within 8 h. The information suggests potential medicinal benefits of the Piper betle leaf extract to inhibit the growth of antibiotic resistant Salmonella spp. isolated from pig farms.

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The impact of macroplastic debris (> 5 mm in size) on marine life is a global concern but is rarely investigated in Thailand. Our objective was to investigate the relationship between stranded sea turtles and macroplastics found in the Central Gulf of Thailand. The turtle (n = 388) stranding record between 2017-2020 was analysed retrospectively to determine their size, species, and interaction with macroplastics. Thereafter, between 2019-2020, macroplastics were collected, from the gastrointestinal (GI) tract of dead turtles and from the beaches where stranded turtles were found. A stereomicroscope was used to visually categorise the macroplastics, and the plastic composition was analysed using a Fourier-transform infrared (FTIR) spectrometer. Green sea turtles (Chelonia mydas) were found to account for the majority of stranded turtles (74%, n = 251), and macroplastics were discovered in 74% of cases of entanglement and ingestion. At the juvenile stage, the stranded turtle was strongly related to macroplastics. Immature turtles were more likely to become entangled than adult turtles. Entangled turtles had a greater survival rate than turtles that had consumed plastic. The plastic fibres were the majority of macroplastics found in the GI tracts (62%, n = 152/244) and on the beach (64%, n = 74/115). Most fibres from GI tracts (83%, n = 126/152) and the beaches (93%, n = 68/74) were identified as the fishing net comprised of polyethylene or polypropylene. We concluded that fishing nets made of polyethylene or polypropylene might be one of the significant causes of sea turtle stranding in the Central Gulf of Thailand, and this issue requires immediate resolution.