While innocently searching the web for an eelgrass (Zostera marina) reference I came across something totally new to me. Apparently, the Ren Ltd of London is selling skin care products using eelgrass extracts.
I'm not sure how they (or rather their suppliers!) gather the grass and do their extracting , but it interesting to see a modern use for a species that had so many historic uses. It is not uncommon to see rafts of grass floating on the waters surface during summer and fall. Possibly these are being gathered and processed...?
I will have to look into this more...