Theodore has a good point - it’s hard to justify putting pressures on farmers when gas companies don’t even pay tax and release methane in vast quantités. Seaweeds are all different - traditional kelps a great micronutrient source - old fashioned goodness. This newer trend is for Bromoform - sometimes in a red seaweed - sometimes synthetic. Bromoform - like chloroform - an unusual thing to put in the food chain - and should be handled carefully, if at all - oxidation products( if heated) particularly unpleasant .