Small-scale temporal and spatial variability in the abundance of plastic pellets on sandy beaches: Methodological considerations for estimating the input of microplastics

Monitoring multi-year macro ocean litter dynamics and backward-tracking simulation of litter origins on a remote island in the South China Sea

“…The density, estimated as the monthly average of 0.2 kg or 4.4 items per a linear meter of the Dongsha beach in this study, was similar to that of studies in remote islands of South Australia (Taffs and Cullen 2005) and the Seychelles (Duhec et al 2015) and an unpopulated beach in Brazil (Santos et al 2008) and much lower than that of coastal ecosystems in relation to specific human activities (Madzena andLasiak 1997, Williams andTudor 2001), all again indicating ocean litter pollution has become global, with both land and ocean loads, in this century, regardless of regions and demographic levels. Although intrinsic differences in litter collection frequencies and size-dependent analyses are likely to confound comparisons and answers for adaptive management (Thompson et al 2004, Ryan et al 2009, Moreira et al 2016, it can be expected that the various threats resulting from poorly managed activities could be highly introduced to coastal and ocean ecosystems, and much work remains to be done to understand litter deposition and movement to address this pressing environmental issue.…”

Factors influencing the detection of beach plastic debris

“…Such data could be easily generated by at least 3-10 independent repeat counts from at least 25-50 distinct sites.258 While these approaches require a more stringent monitoring design and greater monitoring effort, the statistical framework is applied increasingly to large-scale citizen science datasetsIsaac et al, 2014; Tulloch et al, 2013; van Strien et al, 2013) and we envision that results from beach surveys could be analysed in a similar fashion to account for the imperfect 262 detection of plastic. Alternatively, more efficient monitoring designs that use the time to detection to estimate detection probability have proven useful in botanical surveys and may 264 reduce the number of observers required for robust monitoring(Bornand et al, 2014).However, an important consideration for the design of such surveys is the interval between 266 repeat surveys and between surveys that are used to estimate changes over time: the abundance of plastic on a beach is a function of accumulation over time, hence the interval 268 between sampling events will influence the abundance of plastic that is collected(Moreira et al, 2016; Ryan et al, 2014; Smith and Markic, 2013).270 Existing beach surveys and clean-up programmes that do not account for imperfect detection 272 underestimate the amount of plastic on beaches. For these existing datasets, or for monitoring programmes where designs or analyses accounting for imperfect detection are logistically274 impractical, the true amount of plastic could be coarsely extrapolated by using the detection probabilities estimated here.…”

Microplastics: Contaminants of Global Concern in the Anthropocene

“…Em São Paulo, as amostras de microplásticos foram coletadas em sedimentos arenosos de diferentes praias e além da análise da distribuição dessas partículas, também foram investigadas as interações de pellets com poluentes orgânicos persistentes e metais adsorvidos. [71][72][73][74][75][76] Na Baía de Guanabara, os microplásticos foram relatados em amostras de sedimento arenoso coletadas em diferentes praias e em águas superficiais, coletadas com rede de plâncton, em Niterói e Rio de Janeiro.…”