Algae are almost ubiquitous, between microscopic and macroscopic species, and can be found in either fresh water or in oceans. Marine macroalgae, commonly known as seaweed, are plant-like organisms that can be seen by the naked eye and come in many varieties ranging from a few millimetres or centimetres in size, while the largest grow to a length of 30 to 50 meters.

Botanically, macroalgae are classified as green, brown, or red and is estimated to be at least 30,000 known species of macroalgae found in the marine environment.

Given that all the substances that seaweeds need in order to survive are dissolved in the water, macroalgae, unlike plants, have no need of roots, stems, or real leaves. Nutrients and gases are exchanged directly across the surface of the seaweed by diffusion and active transport.

Marine algae draw from the sea a wealth of mineral elements, and also known as a source of vitamins.

Marine algae is used as a natural source of vitamin D to:

• Support healthy immune system and muscle function
• Support bone strength and bone mineralisation
• Support calcium absorption. A diet deficient in calcium can lead to osteoporosis in later life.
• Support muscle function

For several centuries there has been a traditional use of seaweeds as food in China, Japan and the Republic of Korea.

Resources:1. American Scientist, accessed 14 Dec 2020, The Science of Seaweed2. Sustainable Energy Ireland, accessed 14 Dec 2020, A review of the Potential of Marine Algae as a Source of Biofuel in Ireland (2009)