Algae; Importance




Beneficial Aspects                 

Algae have following beneficial effects:

  1. Source of food and fodder:
  2. i) Some algae contain high amounts of minerals, proteins and oils so are used as food for human beings e.g., Ulva, Spirogyra , Oedogonium, Pophyra
  3. ii) Fucus is used as fodder and as hen feed

iii) Diatoms are major source of food for marine fishes.

  1. Producers:

Because of photosynthetic ability algae are major producers on earth. They provide food and energy to aquatic organisms.

  1. Drugs and medicines: 

A number of medicines obtained from algae some are as

  1. Chlorellin is an antibiotic obtained from Chlorella and is affective against gram positive bacteria.
  2. Agar-agar is obtained from Gelidium. It is used a laxative.
  • Brown algae is used in goiter medicines due to high contents of iodine
  1. Nitrogen fixation:

Many algae (Cyanobacteria) convert atmospheric nitrogen to nitrites and nitrates. These compounds are then absorbed by plants for the synthesis of proteins, nucleic acids etc.

  1. Fertilizers:

Brown algae are used as fertilizer due to the presence of minerals.

  1. Uses of diatomaceous earth: 

Diatomaceous earth is formed by the death of diatoms. It is used in tooth pastes, as fire proof

material, to filter oils and syrup in sugar industries. Light weight bricks are prepared from it that are used for building fire proof houses.

  1. Reclamation of soil:

Algae act as soil binder and help in reduction of soil erosion. It also helpful in reclamation of saline soils because it low down the pH of soil and increases the water holding capacity.

  1. Sewage disposal:

In sewage large amount of organic and inorganic compounds are present.

Oxygenation of these compounds is major step in their disposal. Algae such as Chlamydomonas help in oxygenation of these compounds.

  1. Industries

Different chemical compounds and algal products are used in industries such as

  1. i) Algin:  It is used as adhesive in artificial silk, ice creams, paints and many pharmaceutical products, in processing of natural and synthetic rubbers.
  2. ii) Gelatin: Obtained from red algae and is used as bases in shoe polishes, shaving creams, cosmetics, shampoos, glue, jellies, candles and tooth paste.

iii) Agar-Agar: jelly like, non-nitrogenous compound obtained from red algae. It used as base for culture media in laboratory, and in different food products.

  1. iv) Carrageenin: carbohydrate obtained from red algae. Use in preparation of cosmetics, toothpastes, paints and pharmaceutical industry.


Algae have following harmful effects:

  1. Algal Blooms: Algae grow excessively along the shore of ponds and oceans and cause

algal bloom. Algae cover the upper surface of swimming pools. Algae cause eutrophication in ponds and lakes. It causes the death of many fishes due to oxygen deficiency.

  1. Poisonous by products: Decaying algal plants release certain toxic by-products. These compounds are harmful to aquatic animals. Some algae also release toxins which cause the death of animals.
  1. Human diseases: Different algae may cause stomach troubles, respiratory disorders and skin diseases.
  2. Blocking of photosynthesis: The epiphytic algae which are found upon other plants and trees block photosynthesis and indirectly harm the trees and plants.