WP1 encompasses innovations in offshore seaweed cultivation by introducing novel stainless steel structures in pre-existing offshore infrastructures (e.g., wind farms, fisheries, uncommissioned drilling rigs). Rather than installing dead weight anchors, various forms of aquaculture technology such as robust net pens, attached longlines can be implemented in pre-existing infrastructures. These configurations will be assessed to optimize the mechanical properties (grade of stainless steel), the connections with existing infrastructure and the implications on the overall system behavior (biofouling, stress corrosion cracking and cyclic loading). Additionally, current owners or designers of offshore wind farms reject any additional loading coming from secondary purposes for safety reasons. However, these additional loadings have, to date, not yet been thoroughly tested and alternatives (e.g., where the investigated system could be lowered further towards the sea bottom in order to circumvent critical particle velocities induced by storm waves) have not yet been methodically studied. Therefore, novel stainless steel structures will be presently optimized and assessed for strength, maintainability and reliability (under fatigue) when submitted to varying environmental loadings such as hydrostatic, hydrodynamic, organic weight, temperature and cyclic loading (DC1). The nature of the marine environment makes any underwater installation particularly susceptible to corrosion. Therefore, specific attention for the long-term durability of these developed structures will go to the evaluation of the corrosion resistance of these materials. The effect of corrosion will be tested for several suitable grades of duplex stainless steel at different environmental conditions (temperature, salinity, wave-action and light) with specific emphasis on microbial induced corrosion (DC2). At sea monitoring is an important tool to establish an a priori corrosion risk. The development of a mobile autonomous unit that assesses the corrosion risk in a seawater environment across a complete installation such as a seaweed culture complex, is envisaged (DC3). This unit encompasses sensors for pH, temperature, salinity, dissolved oxygen, redox potential and bacterial sulfur metabolites. The unit will be tested at different marine locations and create a corrosion heat map of these locations to characterize the environmental conditions of various configurations. New monitoring technologies and capabilities for material conditions, pre-existing structures and seaweed cultivation/harvesting will be developed (DC4).