It is extracted by warming the seaweed/kelp up.
Sea kelp is a form of seaweed. As it grows, it takes iodine out of seawater. Over time, sea kelp has a much higher concentration of iodine than seawater. Sea kelp is harvested, dried, and burned to collect iodine. There are also several other products on the market containing seaweed that have an antiseptic nature.
beach seaweed
Seaweed gelatin is called agar. It's often used to culture bacteria.
Alcohol.
Agar is derived from seaweed and is often used in Japanese desserts
E407 is carrageenan - a thickener obtained from seaweed.
Yes, Kelp is a seaweed. Seaweed is the common name for most marine algae. Kelp is a type of brown seaweed. See related link
they both live in the water
Seaweed
Pretty common, it's extractable from Kelp/seaweed, but a pain.
Stramenopiles