Algae are a group of organisms that can sustain their nutrition. These plant-like organisms are classified mainly from their size phytoplankton (microalgae) and the seaweeds (macroalgae). Seaweeds are marine, plant-like organisms that are considered ancestors of land plants. These aquatic organisms have very little to no distinct internal transport system. They don’t reproduce by seeds but rather by spores and other unique processes.
Seaweeds belong to three different groups with more than 10,000 species: brown algae (class Phaeophyceae), red algae (phylum Rhodophyta), and green algae (phylum Chlorophyta). Red and brown algae are commonly found in marine while some green algae species are also present in freshwaters.
The Philippine National Herbarium has ~8,000 collections of algae at present with notes on having over a century-old species which was collected in the early 1900s. These macroalgae are extremely valuable to us since they can be a good source of food, supplements, medicines, and fertilizers. Even your favorite toothpaste and shampoo contains carrageenan —an additive extracted from red seaweeds used to thicken and emulsify products.