title: The effect of fine-scale sampling frequency on estimates of beach litter accumulation.
abstract: The effect of sampling frequency on estimates of the rate of litter accumulation was determined for two South African sandy beaches. After initial cleaning, all manufactured items >10mm diameter were collected in alternating bouts of daily or weekly cleanups. Daily sampling collected 2.5 (range 2.1-3.4) times more litter items than weekly samples and 1.7 (1.3-2.3) times more litter by mass. Low density items such as foamed polystyrene showed a greater differential (4-5 times more items from daily sampling), presumably due to faster turnover of lightweight litter items. Variation in weekly samples was not consistently less than daily estimates, suggesting that less frequent samples only partly integrate short-term fluctuations in litter dynamics. Researchers using beach accumulation data to infer trends in nearshore marine litter, or to assess the efficacy of litter mitigation measures, need to ensure consistency in sampling frequency.
authors.affiliation: Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa. Electronic address: pryan31@gmail.com.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Ryan
authors.affiliation: Marine Research Institute and Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa.
authors.forename: Annerie
authors.initials: A
authors.lastname: Lamprecht
authors.affiliation: Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa.
authors.forename: Debbie
authors.initials: D
authors.lastname: Swanepoel
authors.affiliation: Marine Research Institute and Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa.
authors.forename: Coleen L
authors.initials: CL
authors.lastname: Moloney
mesh_terms: D001493:Bathing Beaches; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000032:analysis; D010969:Plastics; D013019:South Africa; D014866:Waste Products / Q000032:analysis*
chemical_list: D010969:Plastics; D014866:Waste Products
keywords: Accumulation; Meta-analyses; Plastics; Sample rate; South Africa; Stranded debris