Microplastics in marine beach and seabed sediments along the coasts of Dar es Salaam and Zanzibar in Tanzania

Microplastics (MPs) pollution in the marine environment has been one of the biggest challenge in developing countries due to a lack of proper solid waste management strategies. This study reports the distribution and types of MPs in beach and seabed zones of the Dar es Salaam and Zanzibar coasts. A total of 641 MPs were identified across all sites, of which 84 % and 16 % originated from beach and seabed sediments, respectively. Fragment and fibers were the most common types in both seabed and beach zone confirming the secondary sources of the MPs. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR), revealed four types of polymers with polyethylene (PE) (56%) and polyester (PS) (24 %) being the most common. Microplastics were more abundant on beaches than in seabed zone. A larger abundance of PE and PS reveals a wide range of MPs entering the Ocean.