Seasonal variation of plastic debris accumulation in the estuary of Wonorejo River, Surabaya, Indonesia

Plastic has emerged as a common pollutant in marine environments. The majority of the plastic debris in oceans originate from river streams. Some of these debris will end up being accumulated in estuaries. This study aimed to investigate the seasonal variation of plastic debris accumulation in the estuary of Wonorejo River in Surabaya, Indonesia. This research focused on the amount of visible plastic debris (VPD) accumulated along the seashore of Madura Strait during the dry and rainy seasons. Three representative sampling points (SPs) were chosen in the Wonorejo River Estuary area. Data normality was tested using the Kolmogorov-Smirnov test and resulted in normally distributed data. One-way ANOVA was used to determine the correlation between seasonal variation and the accumulation of VPD in all SPs. Tukey's honest significance test was used to further analyze the significance of the accumulated VPD in each season. Result showed that the accumulation of VPD was significantly higher during the rainy season compared to dry season (p < 0.05). SP2 showed the highest accumulation of VPD in both seasons. The collected VPD during the dry season were 126.07 +/- 12.00, 375.97 +/- 16.72, and 291.13 +/- 36.28 g/m(2) from SP1, SP2, and SP3, respectively. By contrast, the collected VPD from SP1, SP2, and SP3 during the rainy season were 443.17 +/- 8.92, 1162.37 +/- 84.60, and 706.00 +/- 39.06 g/m(2) respectively. Low-density polyethylene was the major collected plastic component in all SPs during dry season, contributed up to 73.13% of collected VPD composition. During the rainy season, polyethylene terephthalate was dominating the plastic type distribution up to 59.77%. The manual estuary cleanup is suggested to be conducted frequently during the rainy season to achieve an improved cleaning efficiency. (C) 2019 Elsevier B.V. All rights reserved.