Sea6 Energy has raised $18.5 million from BASF’s venture capital fund and other investors. The Indian company uses specialized scaffolding and an automated harvesting boat to grow red seaweed far offshore. It processes the material into fertilizer, animal feed, food ingredients, and other products. Sea6 also hopes to use seaweed as a feedstock for plastics and biofuels. Blue Ocean Barns already makes a feed supplement with seaweed, and CarbonWave has a seaweed-containing emulsifier.