On Earth, algae are simple, autotrophic, eukaryotic organisms that populate all the seas, ranging in size from unicellular diatoms to giant kelps that can grow to 60 meters in length. Whereas on Earth the diversity and quantity of algae were dwindling dramatically before the Seeding due to centuries of pollution acerbated by the fallout from the Great Mistake, on this planet algae are plentiful and can be found in many forms, generally within shallow waters under 100 meters deep. Colonists began harvesting algae soon after establishing coastal settlements, especially the seaweed and kelp varieties. Besides being used as a high-quality food source, algae are used to make fertilizer, pigments, agar and alginates. Pan-Asian colonial scientists also developed various methods of using the planetary algae as a renewable biofuel, continuing research begun on Earth two centuries before but suspended as cost ineffective when algae counts declined. However, the primary use of algae – which contains high levels of omega-3 fatty acids – is as a food, and algae figure prominently in a number of cultures which have transplanted their cuisines to this new world.
Algae is improved by a Work Barge, and will allow a Biofuel Plant to be built in a nearby city, which in turn gives the Algae hex +2 Energy.