Algaculture in trapped waters of inundated coastal areas in the Indian Sundarbans can be a sustainable aquafarming practice for marginal farmers who have lost their land due to sea level rise and salt water intrusion. The present paper tries to assess the bio-economic potentials of algaculture as a sustainable aquafarming practice by analysing the biochemical components of one of the best grown macro algal species, Enteromorpha intestinalis. Perusal of results show that the species is rich in protein and has considerable amount of carbohydrates to deem it fit as an alternate source of food feed and fodder, whereas almost 95% of the available oil can be converted to biodiesel that confirms the standard specifications of EN-24124 in regard to fatty acid methyl esters and linolenic acid contents. This also qualifies the species as an alternative energy crop augmenting its bio-economic potentials.