This thesis explores the experiences of volunteers in coastal cleanup activities, applying the Supportive Environments for Effectiveness (SEE) framework (Basu & Kaplan, 2015). It also investigates whether artistic identity and artmaking moderate the effect of cleanup participation on eco-anxiety. The research utilized a cohort design with mixed methods across five coastal cleanup groups (n = 59). The independent variable is the cleanup of marine debris, with dependent variables: eco-anxiety, measured by the Hogg Eco-anxiety Scale (Hogg, et al., 2021); mental models, measured by a Conceptual Content Cognitive Mapping exercise (3CM; Kearney & Kaplan, 1997); cognitive restoration, measured by a digit span backwards (DSB) task (internal.mesa-nhibi,org, n.d.) and a modified version of Kaplan’s (2001) effective functioning scale; and meaningful action, measured by a modified version of a scale developed by Crandall and colleagues (2019). Participation in marine debris cleanups reduced eco-anxiety; however, neither artistic identity nor art making moderated the effect. Mental models about what it is like to undertake a marine debris cleanup were expanded and skewed more positive; cognitive restoration improved (per DSB task), and participation contributed to a sense of taking meaningful action. These insights can be useful for designing and executing programs to deliver supportive and engaging activities that enhance the volunteer experience.