The synthesis of silver nanoparticles by marine based organisms like algae and microalgae is emerging as a promising method to prepare AgNPs due to their non-toxic and environmentally friendly nature. Marine algae such as Chaetoceros calcitrans, Chlorella salina and Tetraselmis gracilis can reduce silver ions to metallic silver, thereby synthesizing AgNPs . Single cell microalgae are used extensively for the synthesis of AgNPs as it enables the formation of homogeneous suspension that can be used directly in the synthesis of AgNP . The microalgal synthesis of AgNPs is generally carried out by mixing microalgal biomass with the silver solution of AgNO3 which results in the synthesis of AgNPs . The synthesis process in cell wall deficient microalgae is intracellular or extracellular when the synthesis occurs outside the cell, which may be due to the presence of biomolecules . The AgNPs obtained are spherical with an average size ranging from 4.3 nm [144] to . The AgNPs are used as antioxidants and antibacterial . This method synthesizes small size AgNPs with uniform morphology using non-hazardous reagents. However, the production rate is significantly low. . The examples of the Algae used in the synthesis of AgNPs is summarized in table .