Melba Torres Sosa1, Jarrett E.K. Byrnes1, Daniel Lopez1, Katherine Dafforn1, Joe Christo2, Kirk Bosma3, Robert F. Chen1
1University of Massachusetts Boston, USA - 2 Boston Harbor Now, USA- 3Woods Hole Group, USA
Living Seawalls are an initiative to enhance biodiversity on urbanized marine structures to remediate habitat loss in hardened coastal areas. By retrofitting traditional seawalls with marine-grade concrete panels with features mimicking the natural intertidal, such as crevices and pools, these structures aim to restore coastal ecological communities. The success of this approach hinges on understanding processes affecting community assembly on these novel structures. In the marine environment, microbes are the first colonizers of novel surfaces, rapidly forming biofilms, which act as ‘hot spots’ of microbial activity, driving essential processes like nutrient cycling and the breakdown of organic matter. These biofilms establish the conditions that larger organisms, such as algae and invertebrates, encounter during recruitment and settlement. Therefore, understanding how microbial communities assemble and function on living seawalls is critical to evaluating their overall ecological performance. This work investigates early microbial colonization patterns on Living Seawall sites installed in late 2024 in East Boston, Massachusetts—the first of its kind in the US. We sampled 120 panels across two walls (5 treatment types - control, small rockpool, large rockpool, crevice, and swim-through - stratified at three tide heights with four blocks per tide height per site) during early biofilm development. Using 16S rRNA gene sequencing, we characterized bacterial and archaeal communities to assess the influence of panel design and tidal height on community composition. Preliminary findings highlight trends in early microbial diversity and taxa across panel types and tidal zones during this crucial early colonization phase. This work will provide critical insights into microbial community dynamics of the urban coast and inform the Living Seawall design to enhance the ecological performance of urban coastal infrastructure.
Biography
Melba Torres Sosa is a PhD student in the Bioinformatics track of the Integrative Biosciences program at the University of Massachusetts, Boston. She is a member of the Byrnes Lab and the Stone Living Lab. Her research focuses on identifying the effects of coastal armoring and human-made materials on microbial biofilm communities, examining both composition and functional changes. She is also interested in public perceptions of coastal armoring and is passionate about science outreach.