Algae are primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves. They belong to the kingdom of Protista and the size ranges vary from the microscopic Micromonas species to giant kelps that reach 60 metres (200 feet) in length.
Types of Algae
The habitat distribution of the Algae can be determined by their pigment. Although, the majority of the Algae are found in aquatic habitats that might be in freshwater or marine water. Only few species are found extreme conditions like snow, ice or hot spring. There are mainly four types of Algae which are discussed below:
1. Blue Green Algae: They are also known as Cynabacteria. They appear in blue green colour and contain chlorophyll 'a', 'b', and phycobilins.
2. Green Algae: They belong to the family of phylum Chlorophyta and contain chlorophyll 'a', 'b', carotenoids, and xanthophylls. They are unicellular and multicellular.
3. Red Algae: They belong to the family of Rhodophyta and contain chlorophyll 'a',’d’, carotenoids, xanthophylls, and phycobilins. They are used as a stabilizer in milk products.
4. Brown Algae: They belong to the family of Paeophyceae, and contain chlorophyll 'a', 'c', and fucoxanthin pigment. They are used in order to stabilize, thicken, and modify various food products.
They are categorized as: aquatic (planktonic, benthic, marine, freshwater, lentic, lotic), terrestrial, aerial (subareial), lithophytic, halophytic (or euryhaline), psammon, thermophilic, cryophilic, epibiont (epiphytic, epizoic), endosymbiont (endophytic, endozoic), parasitic, calcifilic or lichenic (phycobiont).
Economic importance of Algae
These eukaryotic marine organisms have no roots, flowers and stem. It plays important role in alkaline reclaiming which is used as soil binding agent. They are economically important in a variety of ways which are discussed below:
1. Food: Algae are healthy source of carbohydrates, fats, proteins, and vitamins A, B, C, and E as well as the minerals like iron, potassium, magnesium, calcium, manganese, and zinc. Hence, people of countries like Ireland, Scotland, Sweden, Norway, North and South America, France, Germany, Japan, and China uses it as the food ingredient from the centuries.
2. Fodder: Algae are also used as the fodder to feed livestock such as cattle and chickens.
3. Pisciculture: In fish farming, Algae plays very important role because it helps in the production process. Fish used plankton and zooplankton as a food. It helps in maintaining the health of the marine ecosystem because algae are naturally absorbent of carbon dioxide and also provide oxygen to the water.
4. Fertilizer: Algae are rich in minerals and vitamins. So they also used as liquid fertilizer which helps in the repairing level of nitrogen present in the soil.
5. Reclaiming Alkaline: Blue Green Algae helps in the reduction of high concentration of alkalinity in the soil.
6. Binding Agent: Algae act as the binding agents against natural processes such as erosion.
7. Biological indicator: Algae are very sensitive. If there is a slight change in the environment their pigments changes or might get died. The water pollution is checked with the help of Algae like Euglena and Chlorella.