The belief that fish is good for us is one important reason for the growing consumption of fish in the world. Fish are a rich source of Omega-3 fatty acids, which our body cannot make efficiently. Omega-3 fatty acids are essential for the development of brain and the retina and an abundance of it appears to maintain the health of our central nervous system. Other than this, Omega-3 is also suppose to have anti-inflammatory properties. (Human body converts Omega-3 fatty acids to eicosanoids, which signals the immune system to calm down after it has completed its job). This and many other properties of Omega-3 fatty acids, ensures that a moderate a regular consumption of ocean fish good for us. It so happens that just like humans even fish do not make Omega-3 fatty acids. They obtain it directly or indirectly from tiny oceanic plants called phytoplanktons. Hence farmed fish and fresh water fish, have negligible quantity of Omega-3’s in them, since they do not have access to the oceanic plants. Ergo, your only reliable source of Omega-3 is wild ocean fish. Unfortunately, most of the fish in our polluted waters have become a sponge for industrial and biological toxins. Chemicals from pesticides, industries and other human activities bio-accumulate in the fish. Dioxins, polychlorinated biphenyl’s mercury, lead, cadmium and copper are found in sea fish today. These pollutants, cause liver damage, cancer and affect the foetus in pregnant women. Hence today children and pregnant women are advised not to eat any fish, particularly swordfish, shark, tilefish and king mackerel’s among others. The fish least likely to accumulate toxins are small, short-lived fish from open ocean like Pacific Salmon, common mackerel, sardines and catfish.
When you arrive at a beach or ocean coast, after a prolonged period, do you remember smelling the ocean aroma? A smell that reminds you of your proximity to the sea. This aroma is because of compounds called bromophenols and are synthesised by algae and some primitive creatures from bromine. Bromine is abundant is sea water and bromophenols are propelled into the seacoast air by wave action. Fish also accumulate them, and thus remind us of the sea air. Freshly caught fish has smell of crushed leaves! The large, aroma-less, fatty molecules of both fish and leaves are broken down by enzymes called lipoxygenases into small aromatic fragments. These fragments have a green-leaf like aroma and some freshwater fish produce fragments that smell like melons and cucumbers.