Assessing macroplastic abundances, distribution, and human perceptions along the Mvudi River system, South Africa.

Abstract

Plastics pollution is a ubiquitous problem that poses a threat to society and the environment. The issue is especially pervasive in the aquatic environment, where large amounts of plastic debris accumulate from numerous anthropogenic pathways. Relatively little is known about the extent of macroplastic in African Subtropical Austral Rivers, where management strategies are lacking. This study quantifies and compares the variation in macroplastic abundance along the Mvudi River, South Africa over four sites and four seasons, and also aimed to assess and understand the pro–environmental behaviour within the Vhembe Biosphere Reserve in South Africa. I observed a non–significant difference in macroplastic abundance and variation across sites and seasons, with pollution therefore widespread across these contexts. However, the diversity of plastic debris (i.e., γ–diversity value) generally decreased according to sites (M1-M4) moving away from Thohoyandou town and seasons winter, spring, autumn, and spring) with most macroplastic items collected during winter, while fewer macroplastic items collected during autumn. We observed high abundances of macroplastic debris on the shoreline compared to the mainstream, with high proportional abundances of plastic bags and film (>57.8 %) macroplastic physical type across all sites and seasons. We also observed a high proportional abundance of the polymer Polypropylene (>25.3 %). Pro–environmental behaviour has emerged as one of the strategies that can be used to solve the growing environmental issues in line with achieving sustainable development goals. As indicated by responded plastic bags are preferred because they are cheap and easily available. Significantly positive relationship was observed for gender and separating plastic waste and amount of plastic waste generated. Age and education had significant positive relationships with selected variables, iii however, education and plastic re–use times were negatively correlated. For environmental consciousness behaviour, most variables showed positive significant relationships. The information derived from this study serves as the baseline for understanding seasonal variations in plastic debris and their driving factors on this and other Subtropical Austral Rivers and, promoting a positive attitude towards the environment, encouraging social norms that promote pro–environmental behaviour, and shows providing access to resources and education can all contribute to reducing plastic pollution through pro–environmental behaviour.