Survey of Marine Debris on Beaches of Ondo State: Types, Sources, and Spatial Distribution

Marine debris accumulation on beach shorelines represents a growing environmental concern with significant implications for coastal tourism, fisheries, and wildlife health. This study surveyed the composition, quantity, sources, and spatial distribution of marine debris on three beaches in Ondo State, South West Nigeria: Ilaje, Igbokoda, and Awoye beaches. Standardised beach transect surveys following OSPAR marine debris monitoring protocols were conducted during three survey seasons. Debris items were collected, sorted, and categorised by material type (plastic, glass, rubber, metal, cloth, wood, and other) and source (fisheries-related, household, industrial, and unknown). The density of debris per 100 metres of shoreline was computed for each site and season. A total of 4,312 debris items were recorded across all surveys. Single-use plastics dominated, constituting 64 percent of total debris, followed by fishing-related materials at 21 percent. Spatial distribution analysis indicated higher debris loads at Ilaje beach, which lies adjacent to a major artisanal fishing settlement. Fisheries-related debris, including netting fragments and rope, increased during post-fishing season surveys. Temporal comparison revealed a notable increase in total debris between the first and third survey rounds. Multivariate analysis confirmed that proximity to fishing settlements and the direction of dominant coastal currents were the strongest predictors of debris accumulation patterns. The study recommends community-based clean-up programmes and the adoption of gear marking to trace fisheries-related debris sources. Keywords: marine debris, beach survey, plastic pollution, Ondo State, debris sources.