Public participation and willingness to participate in marine debris management in Batam City: A preliminary assessment using an open-ended contingent valuation approach

Marine debris has become a growing environmental challenge in Batam City, driven by rapid coastal development, increasing tourism, and cross-border waste transport within the Singapore Strait. Understanding community engagement is critical for designing effective waste reduction strategies, yet empirical evidence on local participation remains limited. This preliminary study assesses public willingness to participate (WtP) in marine debris management using an open-ended contingent valuation method (CVM). A total of 70 respondents from five coastal zones Nongsa, Marina, Tanjung Pinggir, Barelang, and Batu Ampar were surveyed in September 2025 through face-to-face interviews. WtP was measured in terms of hours per month that individuals were willing to contribute to beach clean-ups, environmental monitoring, educational campaigns, and related activities. The results show an average willingness to participate of 5.68 hours/month/person, with a median and mode of 2 hours, indicating a highly skewed distribution driven by a small group of highly motivated individuals. Chi-Square analysis reveals that age is the only demographic factor significantly associated with participation levels (p = 0.008), while gender, occupation, and income show no significant relationship. The participation curve follows an exponential decline, and the marginal willingness to participate evaluated at the mean is approximately 0.80 persons per additional hour, suggesting that higher time commitments sharply reduce overall community engagement.