Shellfish have been used as a source of food for many centuries. Shellfish include mollusks and crustaceans, they constitute the paramount component of the seafood produced across the world. They contain a substantial amount of amino acids and omega-3 fatty acids. Shellfish are highly nutritious and consist of ample amounts of various nutrients such as zinc, magnesium, iron, calcium, copper, and iodine. Mounting demand for shrimp, crabs, prawns, lobsters, crayfish, oysters, bivalves, cuttlefish, mussels, clams, squids, and gastropods has led to an increase in their aquaculture, both in fresh and marine water ecosystems. Consumption of shellfish regularly augments the immune system and promotes the development of a healthy brain and heart. Due to exponential growth in population and alteration in food habits, there is a growing demand for shellfish products among consumers, thus marking a remarkable contribution to food security. According to the World Health Organization, it has been revealed that nutrition, food security, and food safety are entwined and cannot be separated. Shellfish act not only as a source of food security but also as a source of an adequate amount of nutrients that are indispensable for good health. Alteration in the climatic conditions poses serious risks to food security, due to the outbreak of various diseases. A decrease in the concentration of carbonate ions owing to the increased CO2 threatens the larvae of shellfish. Aquatic ecosystems that support aquaculture are experiencing significant distortions as a result of the gradual heating of the planet’s temperature. It has been estimated that by the year 2100, primary production in the marine ecosystem will tend to decline by 3–9%, thus jeopardizing food security. Thus, with the expanding global growth and rise in consumer interests, there is a need for constant surveillance of climatic alterations to maintain the abundant supply of shellfish in consumer markets.