Anthropogenic Litter Abundance and Accumulation Rates Point to Seasonal Litter Sources on a Great Lakes Beach

Abstract

The ecology of anthropogenic litter (AL) (i.e., trash) in marine ecosystems is a growing field of research. Freshwater and marine ecosystems have similar AL densities, but research on the assemblage and accumulation rates of AL in freshwater environments is less common. We studied AL accumulation at Pratt beach, located on Lake Michigan in Chicago, IL, USA. The beach has a concrete pier at the south end, with two areas of grass bisected by a walking path. Pratt beach receives many daily visitors, but unlike other urban beaches, it has no daily municipal beach grooming. We established five 60 m transects parallel to the shoreline, with increasing distance to the shoreline. Each transect was divided into four habitat zones (i.e., pier, south vegetation, path, and north vegetation). All AL within 1 m of each transect was collected biweekly from March‐November 2015. AL density (No. m−2) and input rate (No. m−2 day−1) were highest at the pier, regardless of distance from the shoreline. Fall had the highest AL density relative to spring or summer. We concluded AL inputs at the pier were dominated by direct littering and the retention of wind‐ and wave‐blown AL at the pier's wall. The study beach had much higher AL than adjacent beaches which received municipal AL cleaning, suggesting cleaning is effective at reducing AL density. This study suggests that, given the mobile nature of AL by natural processes, infrequent sampling may underestimate total AL abundance. Management efforts for AL should be directed towards the greatest AL accumulation sites within a beach, and at prevention of direct littering from visitors.

Trash Dance: Anthropogenic Litter and Organic Matter Co-Accumulate on Urban Beaches

“…These types are minor contributors to beach litter due to lower offshore activities in the Great Lakes relative to the oceans. In particular, the high relative abundance of smoking-related and food-related AL points to beach visitors as the primary source [7,22,23]. Lastly, the positive correlation between population density and AL density support the local origins of AL on Great Lakes beaches [7].…”

“…Data collection was completed at four Lake Michigan beaches in the Rogers Park neighborhood of Chicago, IL, USA ( Figure 1). Study beaches were selected as they were the subject of previous research on AL abundance [7,22], and are in urban locations with high visitation during the summer. The Chicago Parks Department uses grooming tractors to collect litter at dawn every day throughout the summer ( Figure A1), which, in 2018, was May 28 (US holiday of Memorial Day) to September 3 (US holiday of Labor Day).…”

“…Collection took place on 3 October 2018, which was four weeks after the end of municipal litter maintenance. We selected this date because previous research indicated it was during this time of year when AL is highest on Chicago-area beaches, due to continued visitation and the lack of maintenance in the autumn [7,22]. Our expectation was that this period of high AL density would facilitate the analysis of AL and organic matter co-accumulation.…”

Adapting Coastal Collection Methods for River Assessment to Increase Data on Global Plastic Pollution: Examples From India and Indonesia

“…They determined the main composition of debris found along riversides to be plastics, polystyrene, and manufactured wood, which ranged from 36 to 82% proportionally. Vincent and Hoellein (2017) collected at Pratt beach, Lake Michigan, USA, bi-weekly from March to November of 2015. They reported the highest density of litter in the fall, when compared to spring and summer; their assessment determined that direct littering as well as distribution via wind and waves led to pockets of higher accumulation (Vincent and Hoellein, 2017).…”

“…Vincent and Hoellein (2017) collected at Pratt beach, Lake Michigan, USA, bi-weekly from March to November of 2015. They reported the highest density of litter in the fall, when compared to spring and summer; their assessment determined that direct littering as well as distribution via wind and waves led to pockets of higher accumulation (Vincent and Hoellein, 2017). Evaluating France's Adour River, Bruge et al (2018) worked with stakeholders to collect over 120,000 items across 278 riverbank samples.…”