Plastic Pirates Nova Scotia 2024 dataset: Citizen science investigation of anthropogenic litter pollution of aquatic environments

This dataset describes anthropogenic litter pollution, including plastic pollution, at nine sampling sites at lakes and the ocean in Nova Scotia in the fall of 2024. It comprises data from two different citizen science protocols. The first protocol (“Group A”) assessed litter density per m² and litter type (paper, cigarettes, plastic, metal, glass, food leftover, other). A total of 675 m² were investigated using this protocol, and a total of 495 litter items classified. The second protocol (“Group B”) assessed the litter item composition of individual items, based on 24 litter categories, including nine single-use plastics categories. In total 3032 litter items were collected and sorted into these categories, representing 114 kg of litter. In total, 20 sampling activities (Group A and B combined) were conducted at nine sampling sites. Potential sources of litter items were also evaluated, and each sampling site was described in detail, including coordinates, shape, slope and orientation of the shoreline and accessibility. The data were collected by 275 people from nine organizations, most of them citizen scientists. Collectively, they contributed 635 h of data collection effort, including litter collection, litter sorting and data annotation. Most of the citizen scientists were schoolchildren, aided in their research by their teachers and the coordinators of this project. The implementation of the project in Nova Scotia was part of the Plastic Pirates program (https://www.plastic-pirates.eu/), investigating litter pollution in different countries in cooperation with schoolchildren and teachers. This open access dataset, available on Zenodo (https://doi.org/10.5281/zenodo.16949607) [1] under Creative Commons license CC BY 4.0, can be used to compare litter densities and litter composition across regions in Canada or worldwide, and is of value as a reference data point in time to assess litter pollution in temporal litter studies.