In the 1950s and 1960s , something weird happened in the estuaries next to the long island sound , new York and Connecticut . Birds of prey , ( eagles ) fed on fish in the estuaries had soaring concentrations of the insect killer DDT in their bodies. Even though when the water in the estuaries was tested , it had low concentrations of DDT. In consequence , poisons that dissolve in fat (such as DDT) , can become more intense as they upgrade up in the a food chain in a process called biological magnification. When the pesticide mixes with the water , algae and bacteria are effected with the poison . when fish eat the algae and bacteria , the poison spreads and dissolve in the fat of the fish . Each time the eagle feeds on the fish