The hyperbenthic environment: A forgotten habitat for plastic pollution

V. Fagiano, M. Compa, C. Alomar, M. Morató, S. Deudero, 2023. The hyperbenthic environment: A forgotten habitat for plastic pollution. Marine Pollution Bulletin. Volume 194, Part A, September 2023, 115291. https://doi.org/10.1016/j.marpolbul.2023.115291

Abstract: This study investigates the abundances and composition of microplastics (MP) among the shallow layers of a coastal Mediterranean Marine Protected Area (Cabrera MPA), seafloor sediments, hyperbenthic environment, and the water column. The mid waters samples were collected mid-way between the sea surface and the seafloor and hyperbenthic samples at the water layer adjacent to the seafloor. Sampling was carried out on patchiness seafloor of Posidonia oceanica meadows. The seafloor sediments showed a mean abundance of 378,769.20 ± 508,109.11 MPs/m3, three orders of magnitude higher than the hyperbenthic (209.17 ± 117.07 MPs/m3), and the mid waters layer (106.48 ± 107.17 MPs/m3). An increasing vertical gradient in MP abundances, mainly composed of fibers was observed. Fibers were made-up mainly of polystyrene (PS, 25 %), expanded polystyrene (EPS, 18 %) and cellulose acetate (CA, 16 %). The results stress the need to increase efforts to find solutions to mitigate fiber pollution in the marine environment.

Keywords: Microplastic, Hyperbenthic environment, Sediments, Fibers, Benthic boundary layer