From the New Yorker
Today, the fortieth anniversary of Earth Day, is the perfect occasion on which to feature the work of Rachel Carson, whose book, “Silent Spring” gave birth to the modern environmental movement.
In the first part of “Silent Spring,” published in 1962, Carson, having already enumerated the poisonous properties of such commonly used chemicals as DDT and dieldrin, describes the accumulation of those toxic compounds in the earth’s water supply. (The movement from the general idea to the specific instance in this passage is characteristic of Carson’s writing and a source of much of its power.)
Water, of course, supports long chains of life—from the small-as-dust green cells of the drifting plant plankton, through the minute water fleas, to the fish that strain plankton from the water and are, in turn, eaten by other fish or by birds, mink, raccoons, and man himself, in an endless transfer of materials from life to life. We know that the minerals necessary for all these forms of life are extracted from the water and passed from link to link of the food chains. Can we assume that the poisons we introduce to the waters will not follow the same course? The answer is to be found in the recent history of Clear Lake, California. Clear Lake lies in mountainous country some ninety miles north of San Francisco and has long been popular with anglers. The name is plainly inappropriate; actually, the lake is rather turbid, because its bottom, which is shallow, is covered with soft black ooze. Unfortunately for the fishermen and the resort dwellers on its shores, its waters have long provided an ideal habitat for a small gnat. Chaborus astictopus. Although the gnat is closely related to mosquitoes, it is not a bloodsucker…. However, human beings who came to share its habitat found it annoying, because of its sheer numbers. Efforts were made to control it, but they were largely fruitless, until, in the late nineteen-forties, the chlorinated-hydrocarbon insecticides offered a new weapon. The chemical chosen for a direct attack was DDD, an insecticide that apparently offered fewer threats to fish life than DDT…. The lake was surveyed, its volume was determined, and the insecticide was applied in the concentration of one part to every seventy million parts of water. Control of the gnats was good at first, but by September of 1954 the treatment had to be repeated, and this time the chemical was added in the concentration of one part in fifty million parts of water. The destruction of the gnats was then thought to be virtually complete.
The following winter months brought the first intimation that other life was affected; the western grebes on the lake began to die, and soon more than a hundred of them had been reported dead. At Clear Lake, the western grebe is a breeding bird and also a winter visitant, attracted by the abundant fish of the lake. It is a bird of spectacular appearance and beguiling habits, building floating nests in shallow lakes of the western United States and Canada…. Following a third assault on the ever-resilient gnat population, in September, 1957—again in a concentration of one part of DDD to fifty million parts of water—more grebes died. Both then and in 1954, no trace of infectious disease could be discovered in examination of the dead birds. But when someone thought of analyzing the fatty tissues of the grebes, they were found to be loaded with DDD in the extraordinary concentration of sixteen hundred parts per million. How could the chemical have built up to such prodigious levels? When the fish of Clear Lake were also analyzed, the picture began to take form: The poison had been picked up by the smallest organisms, concentrated, and passed on to the larger ones, which concentrated it further…. It was a house-that-Jack-built sequence, in which the large carnivores had eaten the smaller carnivores, which had eaten the herbivores, which had eaten the plankton, which had absorbed the poison from the water.