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.

The Levantine Basin at the south-eastern corner of the Mediterranean represents the trailing edge of the distribution of native Atlanto-Mediterranean species, where they are exposed to the most extreme temperature and salinity conditions. The region is also fast warming and exposed to a flood of alien species, mostly thermophilic ones from the Indo-Pacific. The Levant coast also hosts a unique, fragile and understudied rocky intertidal ecosystem – vermetid reefs. Anecdotal historical data and observations, and recent extensive intertidal and shallow subtidal community surveys on the Israeli coast (including a marine reserve) indicate that Levant reefs are (1) overfished; (2) highly invaded by thermophilic alien species, some (rabbitfish) highly destructive; (3) dominated by turf barrens (canopy-forming brown algae are rare, probably overgrazed by rabbitfish) and increasing patches of alien algae and (4) suffering the loss of many native species (e.g., urchins subtidally and the main reef-building vermetid gastropod, Dendropoma petraeum, intertidally). Laboratory work has shown that many native species that are still abundant are likely to disappear under increasing warming, while aliens are much more resistant. Mesocosm experiments demonstrated that, under both warming and acidification, the community structure will further shift, and whole community functions will transform from autotrophic to heterotrophic.