1. INTRODUCTIONAquaculture within agriculture is the fastest growing food production sector in the world. Fish are known as the “food gold” of the present and future.[1] They are also known to be the richest source of high-quality protein. Marine and aquatic environments are home to a great diversity of organisms ranging from prokaryotes to higher vertebrates. Unfortunately, these environments also act as a sink for a wide variety of anthropogenic pollutants, many of which are toxic. Sources of water pollution include fossil fuel combustion, industrial wastewater, sewage treatment plants, agriculture and diffuse runoff, etc. It is important to understand the impact and effect of these chemicals on aquatic life forms. Aquaculture is ecosystem-based and makes a substantial contribution to the Indian economy and also provides livelihoods to millions of people. Fish are very nutritious and eaten as a delicacy food around the world. A variety of contaminants, including toxic heavy metals (cadmium, arsenic, mercury, lead), are ubiquitous in rivers and reservoirs and are disadvantageous to aquatic life.[2]The term "heavy metal" has various meanings in the different countries. branches of science. Metals were first used by primitive man, which marked the beginning of modern industry and commerce. Earlier, during the slow transition from the use of stones to metals, various techniques were discovered for the extraction of metals from their ores, and these methods were improved by early civilizations.[3]The corresponding elements to this description include lead, mercury, arsenic and cadmium. Heavy metals can be defined as those natural elements whose high paper ......ter content in this river remains stagnant for several months a year.• Presence of heavy metals in vegetables that are grown with water from Yamuna, which makes them dangerous for health. • Yamuna now releases ammonia gas into the air, causing difficulty breathing and permanent damage to the lungs. It also releases hydrogen sulfide gas which smells like rotten eggs, which causes bronchitis, respiratory problems including asthma. Excessive pollution in Yamuna has resulted in the annihilation of all life forms except toxic bacteria. • Arsenic levels have increased 20 times over the past 20 years. years in the river is directly responsible for the sudden death of around 156 gharials in the Chama river and thousands of fishes in the river between Vrindavan and Mathura in one year, Fig.5: Yamuna water near Okhala dam, DelhiFig.6: Yamuna water near Okhala Dam, Delhi. Okhala Dam, Delhi