Facts about Macrocystis pyrifera 

Macrocystis pyrifera, also known as Giant Kelp, is a perennial kelp and one of the largest and fastest growing seaweeds of brown kelp. It can become 30-45m long and around 50cm wide. It is attached to a hard bottom by a holdfast and has stipes, around 1cm in diameter and consisting of three or four branches, arising from near the base. The blades grow alternately and irregularly along the stipe and contain a gas bladder at the base, aiding in buoyancy control, which is important for sunlight exposure and growth. The kelp can form dense canopies, primarily located in the subtidal zone.  

Macrocystis pyrifera is found in temperate coastal water and is particularly abundant in California, Oregon and British Columbia. It is also generally found along the west coast of North America as well as in Chile, Argentina, southern Australia and New Zealand, with nutrient-rich and cold or temperate waters. Turbidity is necessary for sufficient nutrient supply and for promoting CO2 and O2 exchange. However, excessive currents can cause the seaweed to be torn from its substratum.    

Macrocystis pyrifera can be used as foods or food additives as well as feed. It contains cellulose, polysaccharides (laminarin, alginate), polyunsaturated fatty acids (EPA, DHA), minerals (iodine, potassium, calcium, magnesium, iron, and phosphorus), and polyphenols. It is also a great source for vitamin A, B, and C. The alginate can be used as stabiliser, emulsifier and gelling agent in foods, while phlorotannin’s have antidiabetic and antioxidant activity.  

Macrocystis pyrifera extracts are also used in pharmaceutical products such as sodium and calcium alginate in wound dressings, alginic acid powder to treat gastric reflux, calcium alginate beads to increase controlled release of drugs etc.