Barrages Influencing Microplastics Distribution and In-gestion; a Case Study

Plastic pollution is becoming a serious environmental concern because of extensive plastic use worldwide. Before being dumped into the marine environment, these anthropogenic polymers also af-fect freshwater ecosystems. Although extensive research has been done to evaluate the level and distri-bution of these anthropogenic polymers but the effect of physical structures like barrages has never been accounted so far. This study is the first of its kind to highlight the role of river barrages in determining the distribution of microplastics (MPs) and affecting their ingestion among different fish species. This study was conducted on Balloki Barrage located on Ravi River, receiving sewage water from different populous cities of Pakistan including Lahore and Sheikhupura. Water (n=6), sediment (n=6) and fish (n=28) sam-ples were collected from both the upstream and downstream of the barrages to establish the relationship between MPs ingestion, fish feeding habit and the pollution level in environmental matrices. On the other hand, the relative abundance of fibers in all the fish species was 57% followed by sheets 34% and fragments 8%. Omnivore fish species were found to have more MPs than herbivores and carnivores irrespective of their size and weight. This study proved that the barrages serve an important function in determining the MPs distribution and their consequent ingestion in fish. A proper consideration must be given to the effects of these structures when evaluating plastic pollution in any riverine body.