Seaweed is the ultimate future food. Not only does it thrive in the rising seas of our future, it is also low-impact (and often low-effort) to farm, highly nutritional, sequesters carbon and nitrogen runoff effectively while growing, and provides a nurturing habitat to mollusks and fish.

A lifelong eater of seaweed, I have been casually observing the effort to increase both the production and consumption of seaweed in the US. As I scrolled through beautiful photos of kelp farms in Maine on Instagram one day, though, I suddenly realized that I didn't know very much about how the various seaweeds I've eaten over my life are grown or foraged, or even how they differed from each other.

Before long, I was 50 open tabs deep into a Wikipedia rabbit hole that consumed me for an entire day, spitting me out only after I'd filled a notebook page with crazed detective scribbles about seaweed families and Latin binomials. I learned that wakame is considered an invasive species in North America; that most of the types of seaweeds we eat are brown algae but that the most common—nori or gim or 紫菜 or laver—is a red algae; and that brown, red, and green algaes have been flung into separate kingdoms based on genetic testing.

Last week, those notes came to mind as I sat by the ocean on Mactan Island, popping briny raw sea grapes—a variety of seaweed I'd never tried before—between my teeth. This weekend, while taking a much-needed breather from nonstop traveling and socializing and working, I decided to fill a quiet Saturday afternoon by digitizing those notes into a diagram. Of course, that process led to even more seaweeds and even more questions.

First draft of the digital map, made in OmniGraffle

As with the plastic and food waste logs, I don't really know where this is going. What I do know is that there is a seaweed in Hawai'i (Sargassum echinocarpum, or limu kala) which is used in a conflict resolution ritual, and that seaweed is used to make breads in Europe and desserts in Southeast Asia, and that Mactan Island produces 4800-6000 tons of sea grapes a year, that mozuku (Cladosiphon okamuranus) is harvested off the Okinawan coast not only as a food but also to make a promising anti-cancer drug.