Characteristics of Microplastics in Water and Fish and Their Relationship with Migration from the East Coast of Surabaya, Indonesia

Microplastics (MP) contamination has become a crucial aspect of research concerning water environments including fish. The East Coast of Surabaya, Indonesia, is one of the fishery areas in the eastern part of Java Island, with MP in its waters having a negative impact on fish consumption. This study specifically focused on analyzing the characteristics of MP in both water and fish (gills and digestive tract). The results revealed approximately 0.46 particles/L of water, with fragments being the predominant form (79.9%), black color (54.9%), and a size range of 20-40µm. Eight species of fish showed the highest abundance of MP in the digestive tract (41.2-66.9%) and gills (33.1-58.8%). Overall, the physical characteristics of MP in fish are dominated by fragments (94.4%), black color (80.1%), and a size of 20-40µm (36.6%). Meanwhile, the polymer composition of MP in both water and fish is dominated by polypropylene (PP, 75%) and high-density polyethylene (HDPE, 25%). Based on the type of migration, M. cephalus as catadromous has the highest MP accumulation with a total of 1,194 and the lowest accumulation is Rhynchobatus sp. as oceanodromous with an accumulated total of 390. The fish organ that accumulated the most MPs is the digestive tract, showing a tight relationship with feeding behavior. Meanwhile, the relationship between migration type and microplastic accumulation still needs further study to provide accurate evidence.