Pharmaceuticals/fine chemicals.

Whereas land plants require a rigid structure capable of withstanding the constant pull of gravity, marine plants must have a more flexible structure to accommodate the varying stresses of currents and wave motion. They have adapted accordingly by developing hydrophilic, gelatinous structural materials having the necessary flexibility. Seaweeds have many other important but in general low volume uses. Because they can concentrate trace elements, seaweed historically have been a source of iodine, potash and other minerals used in industry and medicine. For drugs, including anticoagulants, antibiotics, antihelmenthes (worms), antihypertensive agents, reducers of blood cholesterol, dilatory agents and insecticides.

The most important industrial use is as a Phycocolloids. Primarily constituents of brown and red algal cell walls.
They serve a structural function analogous to but differing from, that of cellulose in land plants. Because of this structural function they are termed hydrocolloids or phycocolloids. This display of colloidal properties when  extracted from seaweeds (the Greek word for seaweed is phycos) and dissolved in water.  They are composed of high-molecular-weight polymers of simple sugars and thus are polysaccharides.

The abovementioned characteristics of phycocolloids are what lend them so well to incorporation into solutions that need to exhibit uniformity and consistence of all solutes in solution. Our body is contain more water than any other mineral or substance. The control and ability to maintain structure of vital importance to life and stability.

Another important property their biological activities, such as to aid in preventing bacterial degradation.
The production of phycocolloids is increasing about 10 % a year.
Shemberg Corporation is a Philippines based company that has taken the initiative to manufacture agar in the Philippines. Until then all seaweed harvested was exported.

Now close
too 100,000. families work year round, harvesting and processing seaweed and another 40 000 families part time.
Approximately 80 % of agar comes from the Philippines.  Now they are even importing dried seaweed from Indonesia for processing.