The chapter continues to focus on multispecies interactions. Dual-habitat built environments remain central to the analysis, but with an emphasis on species translocations and their impacts on biosphere integrity. The chapter addresses the questions of how and why hard surface structures made from steel or concrete, particularly offshore oil and gas platforms, became new and important vectors for marine bioinvasions in the oceanic Anthropocene. In such bioinvasion cases, a species multiplies exponentially in a new ecosystem, dominating it in terms of biomass or density. Slowly moving or stationary structures opened entirely new marine regions to marine bioinvasions and created novel material conditions for them. The use of new hard surface floating structures along coastlines or further offshore supplanted wooden structures and their previous habitat conditions. New bioinvasion pathways emerged through convergence with coastal urbanization and industrialization during the second half of the twentieth century, adding more hard surfaces such as water intake tunnels, piping systems, and seawalls—and now also interacting with offshore wind turbines, floating buildings, and others.