Microplastic abundance in feces of lagomorphs in relation to urbanization.

The presence of microplastics (MPs) in marine environments has been extensively documented. However, studies of terrestrial species are scarce. Fecal samples (105) of lagomorphs were collected at sites with different levels of urbanization in the Baja California Chaparral and analyzed to quantify and characterize MPs found in the feces. The lagomorph species recorded in the study area are the desert cottontail rabbit (Sylvilagus audubonii), brush rabbit (Sylvilagus bachmani), and black-tailed jackrabbit (Lepus californicus), which play important roles in the food web of the chaparral ecosystem. Microplastics were identified using attenuated total reflectance Fourier transform infrared spectroscopy. Microplastics were detected in 49 % of the samples, with fibers being the dominant shape found (72 %). Most (75 %) of the MPs were <1 mm in size, with a mean length of 0.93 ± 0.99 mm (median 0.60 mm, range 0.02 - <5 mm). Polyamide was the dominant polymer (54 %), indicating that MPs are likely derived from textiles; polyethylene was also abundant (27 %). A difference was also observed in the abundance of MPs in feces from sites with different levels of urbanization, with the highest abundance in feces from the urban sites.

First report of plastic contamination in batoids: Plastic ingestion by Haller's Round Ray (Urobatis halleri) in the Gulf of California.

The presence of microplastics has been reported in the marine environment and these pollutants have also been reported in food webs. Information about the presence of microplastics in the Haller's Round Ray (Urobatis halleri) and bottom sediments off the east coast of the Gulf of California is non-existent. The digestive tracts of individuals of this species and sediment samples were examined for plastic particles in this region. In total, 107 plastic particles were found in the sediment. All were fibers and 94.4% were microplastics, the rest were mesoplastics. The gastrointestinal tracts of 142 rays were analysed, and it was determined that this is a benthic feeder. A total of 386 plastic particles were recovered from 46 individuals (32.4%). On average 10.2 (±7.4) plastic particles were found per specimen, with plastic lengths ranging from 0.00821 mm to 0.953 mm. The FTIR-ATR analysis revealed the presence of six types of polymers: polyamide or nylon polyethylene, polypropylene, and polyacrylic were found in both sediments and gastrointestinal tracts of Haller's Round Ray. Polyethylene terephthalate and polyacrylamide were only found in the gastrointestinal tracts of the ray. These polymers are consistent with the human activities undertaken in this area, specifically intensive small-scale and industrial fisheries, as they are used for the elaboration of fishing nets, plastic bags, storage containers, clothing, and fishing boats maintenance. Our results show that benthic feeders are exposed to plastic debris, and its presence is another potential threat to batoids, which are already threatened by bycatch, overfishing, and other pollutants. However, studies on the ingestion of plastic debris in batoids and its presence in the sediment are still scarce or non-existent for this region. As such, these studies are necessary to help in the preservation of these species.

Microplastics in stormwater runoff in a semiarid region, Tijuana, Mexico.

Land-based sources are considered the most important source of microplastic pollution to marine environment. Stormwater runoff has been identified as one of the main pollutant contributors to water bodies. Seven sites were sampled to identify and quantify microplastics in stormwater runoff in Tijuana, Mexico. The median microplastic abundance found in the samples was between 66 and 191 particles L-1, the highest abundance being recorded in an industrial land use site. The estimated annual total microplastic loads were between 8 × 105 and 3 × 106 particles ha-1. The most abundant microplastic shape and identified polymer type were fibers and polyethylene, respectively. The highest microplastic abundances were observed in events with higher rainfall. The results have shown that stormwater runoff is an important source of microplastic to water bodies.

Microplastics on sandy beaches of the Baja California Peninsula, Mexico.

Microplastics have become a concern in recent years because of their negative impact on marine and freshwater environments. Twenty-one sandy beach sites were sampled to investigate the occurrence and distribution of microplastics on the sandy beaches of the Baja California Peninsula, Mexico, as well as their spectroscopic characterization and morphology. Microplastics were separated using the density method and identified using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR). The mean abundance of microplastics in the samples was 135 ±â€¯92 particles kg−1, and fiber was the most abundant microplastic found in the samples, comprising 91% of the total microplastics identified. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis of the microplastics showed that the main polymers found in microplastics were polyacrylic, polyacrylamide, polyethylene terephthalate, polyesters, and nylon.