Project Title: Effects of microplastic particles in Cape Cod salt marshes
Duration: Sample collection: June and July 2025
Lead Investigator / onsite-contact: Ivan Valiela / Kelsey Chenoweth
Affiliation: Marine Biological Laboratory
Contact: kchenoweth@mbl.edu
Project Description: Discharges of microplastic particles (MP, 1nm-5mm) from different watersheds within the Waquoit Bay estuarine system not only depend on the degree of urban land use on each watershed, but the discharged microplastics from the different watersheds are also effectively incorporated into salt marsh sediments. This provides a ready-made regional experiment in microplastic loading, where we can measure effects of differing abundance of microplastics in the underlying sediments on the salt vegetation growing on the sediments, and then with effects potentially propagating on to the fauna present. The differential microplastic loading rate from the different watersheds unto the receiving salt marshes allows testing a series of questions on a potentially growing concern about maintenance of healthy coastal wetlands:
1) do vertical MP profiles in salt marsh sediment reflect recent history of MP delivery and sequestration?
2) does MP sequestration in sediments of different salt marsh habitats differ?
3) does MP content in marsh plants and macroalgae reflect MP abundance in underlying sediment?
4) does increased exposure to MPs affect plants and macroalgae in salt marshes?
5) do effects of MP abundance propagate up salt marsh food webs?
6) which marsh animal species are most sensitive to MP effects?
