Hydrodynamic Control of Microbiologically Influenced Corrosion at the Sediment–Water Interface in Offshore Marine Environments

Hydrodynamic Control of Microbiologically Influenced Corrosion at the Sediment–Water Interface in Offshore Marine Environments | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Hydrodynamic Control of Microbiologically Influenced Corrosion at the Sediment–Water Interface in Offshore Marine Environments Sara Taghavi Kalajahi, Jan Lisec, Elyas Ghafoori, Torben Lund Skovhus, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9073333/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Microbiologically influenced corrosion (MIC) represents a significant threat to offshore infrastructure (such as monopile) operating in the mud zone. The sediment–water interface creates an aggressive environment, where steel structures are in direct contact with sediment, and oxygen availability is limited, creating conditions favorable for anaerobic microbial activity and MIC. At the same time, near-bed hydrodynamic conditions in offshore environments are inherently heterogeneous, even within nominally laminar regimes. However, despite this variability, a mechanistic understanding of how small changes in near-bed flow modulate biofilm development, mass transport, and dominant MIC mechanisms remain limited. Here, we investigated the role of controlled laminar hydrodynamics under anoxic sediment–water interface conditions relevant to offshore wind monopiles. Carbon steel coupons were exposed in a column system inoculated with the North Sea sediment communities. Corrosion rates and pit morphology were quantified by gravimetry and three-dimensional surface profilometry, while microbial community composition (16S rRNA gene sequencing), dissolved sulfide, and untargeted metabolomics resolved the governing biogeochemical processes. The result indicated that static (no flow) conditions promoted diffusion-limited biofilms dominated by sulfate-reducing bacteria (SRB) and acetogens, resulting in low and relatively uniform corrosion. Low laminar flow conditions enhanced syntrophic interactions and sulfide accumulation, producing moderate corrosion severity. In contrast, higher laminar flow reduced bulk sulfide accumulation and biofilm thickness yet generated the most pronounced pitting rate. These findings demonstrate that MIC cannot be confirmed or excluded based solely on sulfide concentration, microbial presence, etc. Rather, corrosion emerges from the coupled interplay between hydrodynamics, biofilm architecture, mass transport, and electrochemical surface processes. Physical sciences/Engineering Earth and environmental sciences/Environmental sciences Biological sciences/Microbiology Earth and environmental sciences/Ocean sciences Microbiologically influenced corrosion (MIC) Offshore wind monopiles Near-bed hydrodynamics Sediment–water interface Sulfate-reducing bacteria Pitting corrosion Laminar flow Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementary.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 30 Mar, 2026 Reviews received at journal 30 Mar, 2026 Reviewers agreed at journal 11 Mar, 2026 Reviewers invited by journal 10 Mar, 2026 Editor assigned by journal 10 Mar, 2026 Submission checks completed at journal 10 Mar, 2026 First submitted to journal 09 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9073333","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":604660585,"identity":"5cc64f02-d104-4977-9ef4-4925e9674b1d","order_by":0,"name":"Sara Taghavi Kalajahi","email":"","orcid":"","institution":"Bundesanstalt für Materialforschung und -prüfung (BAM)","correspondingAuthor":false,"prefix":"","firstName":"Sara","middleName":"Taghavi","lastName":"Kalajahi","suffix":""},{"id":604660586,"identity":"98f77829-38f9-4c7b-87eb-0d6a6d033de6","order_by":1,"name":"Jan Lisec","email":"","orcid":"","institution":"Bundesanstalt für 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