Microplastics in beach sediments and cockles (Anadara antiquata) along the Tanzanian coastline.

Little is known about the prevalence of microplastics (MPs) in East Africa. In the present study, sediments were sampled at 18 sites along the Tanzanian coast that exhibit different levels of anthropogenic activity and were extracted using floatation methodology. Cockles (Anadara antiquata) were collected only from eight sites and MPs were extracted following NaOH digestion. MPs were most abundant at Mtoni Kijichi Creek (MKC, 2972 ± 238 particles kg-1 dry sediment), an industrial port in Dar es Salaam, and significantly higher than all other sites where the abundance range was 15-214 particles kg-1 dry sediment (p < 0.05, one-way ANOVA). Fragments and fibers were found at all sites. Polypropylene and polyethylene were identified polymers. MPs were found in cockles from all sampled sites with both frequencies of occurrence and MPs per individual subject to site-specific variation. This study provides a baseline of MP data in a previously uninvestigated area.

Collection of Anthropogenic Litter from the Shores of Lake Malawi: Characterization of Plastic Debris and the Implications of Public Involvement in the African Great Lakes.

Anthropogenic debris is an environmental problem that affects beaches and coastlines worldwide. The abundance of beach debris is often documented with the use of public volunteers. To date, such community participations have been largely confined to the marine environment, but the presence and impact of anthropogenic debris on freshwater shorelines has been increasingly recognized. Our study presents the first such information from the African Great Lakes, specifically Lake Malawi. A total of 490,064 items of anthropogenic litter were collected by over 2000 volunteers in a clean-up campaign that took place annually between 2015 and 2018. Approximately 80% of the anthropogenic debris was comprised of plastic litter, with plastic carrier bags being the most common item. The dominance of plastic litter, and in particular the presence of plastic bags, which have subjected to bans in some African countries, is discussed. The broader implications of citizen science in the African Great Lakes area is also discussed.