Seagrass meadows provide a wide variety of ecosystem services around the world, making them a highly valuable ecosystem throughout coastal areas. Amongst them, are their contribution to coastal sediment stabilization and their role as carbon sinks. Furthermore, their ability to act as a physical filter of particles in suspension, generally composed of organic matter, is critically important to maintain associated food webs. These services are the result of seagrasses being able to modify coastal hydrodynamics as a function of their physical attributes, such as biomechanical properties, morphology, density. Their capacity to attenuate water movement and enhance particle trapping could imply that seagrass meadows may also act as "sinks for plastics”, and recent studies have highlighted the role of plant density in determining microplastic trapping under unidirectional flow conditions. Here we investigated for the first time the role of wave, currents, and their interactions on the capability of microplastic retention by eelgrass Zostera marina under different shoot density conditions. As seagrass beds act as a physical filter for microplastics and favour their sedimentation, these results will have important repercussions on the biodiversity and in future management and mitigation strategies of plastic waste.

Primary Presenter: Julia Máñez-Crespo, IMEDEA (julia.manez@gmail.com)

Authors:

María Maza, Instituto de Hidraìulica Ambiental de la Universidad de Cantabria (IHCantabria)  (mariaemilia.maza@unican.es)

Bárbara Ondiviela, Instituto de Hidraìulica Ambiental de la Universidad de Cantabria (IHCantabria)  ()

Inés Mazarrasa, Instituto de Hidraìulica Ambiental de la Universidad de Cantabria (IHCantabria)  ()

Gema Hernan, Instituto Mediterráneo de Estudios Avanzados, IMEDEA (CSIC-UIB)  ()

Rocío Jiménez-Ramos,  Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, International Campus of Excellence of the Sea (CEIMAR)  ()

Luis G. Egea,  Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, International Campus of Excellence of the Sea (CEIMAR)  ()

Fiona Tomas, Instituto Mediterráneo de Estudios Avanzados, IMEDEA (CSIC-UIB)  ()