Put up signs to discourage littering
Overall effectiveness category No evidence found (no assessment)
Number of studies: 0
Background information and definitions
Signs may be erected in/around marshes or swamps to discourage casual littering or large-scale waste dumping (Korb 2018). Solid waste can smother or physically damage vegetation, especially herbs and young plants. Anti-littering notices may or may not have a legal basis (i.e. littering/dumping may or may not be illegal). They may be included as part of general information boards.
Although we found no studies evaluating the effects of this action in marshes or swamps, more general psychological studies suggest a combination of anti-littering signs but the presence of litter – suggesting other people have ignored the sign – can actually make people more likely to litter (Keizer et al. 2011).
Related actions: Restrict vehicle use and Restrict pedestrian access, including through erecting signs; Put up signs to discourage fires; Raise public awareness about marshes or swamps, including through erecting information boards.
Keizer K., Lindenberg S. & Steg L. (2011) The reversal effect of prohibition signs. Group Processes & Intergroup Relations, 14, 681-688.
Korb P. (2018) Protected Wetlands Marked with Anti-Litter Sign. Available at https://patch.com/new-york/islip/protected-wetlands-marked-anti-litter-sign. Accessed 10 February 2020.