early after its initial use. In 1946, Clarence Cottam and Elmer Higgins of the U.S. 



Fish and Wildlife Service wrote: 



From the beginning of its wartime use as an insecticide the potency of DDT has been 

 the cause of both enthusiasm and grave concern. Some have come to consider it a 

 cure-all for insect pests; others are alarmed because of its potential harm. . . .DDT, 

 like every other effective insecticide or rodenticide, is really a two-edged sword; the 

 more potent the poison, the more damage it is capable of doing. . the most pressing 

 requirement is a study to determine the effects of DDT as applied to agricultural 

 crops on the wildlife and game dependent upon an agricultural environment. About 

 80 percent of our game birds, as well as a very high percentage of our nongame and 

 insectivorous birds and mammals are largely dependent upon an agricultural envi- 

 ronment. In such places application of DDT will probably be heavy and wide- 

 spread; therefore, it is not improbable that the greatest damage to wildlite will occur 

 there. Because of the sensitivity of fishes and crabs to DDT, avoid as far as possible 

 direct application to streams, lakes and coastal bays. 



Subsequent events have confirmed the observations and predictions of Cottam 

 and Higgins. For instance, one of the impacts upon marine ecosystems was the 

 reproductive failure in the brown pelican population on Anacapa Island, off the 

 California coast, from 1969 to 1972. The accumulation of DDT and its degradation 

 products, primarily DDE, by marine organisms that were the pelicans'food initiated 

 the problem. The source of the DDT was allegedly the wastes from a chemical 

 manufacturing plant in Los Angeles. The result was the production of thin egg shells 

 that broke easily (Risebrough, 1972). 



The general use of DDT and other chlorinated hydrocarbon pesticides was 

 restricted in the early 1970s by the United States and many northern hemispheric 

 countries. Of importance in the DDT story is a criterion for the outlawing of its 

 use, its impact upon nontarget organisms, and the loss of integrity of ecosystems, 

 both on land and in the sea. 



THE MONITORING MODE 



Over the past three decades a large number oi polluting substances have been 

 identified as entering the marine environment (NOAA. 1979). In general they can be 

 classified into nine groups: 



I. The synthetic organic chemicals, including such halogenated hydrocarbons as 

 DDT and its degradation products. Kepone, the polychlorinated biphenyls, 

 and low molecular weight halocarbons such as carbon tetrachloride and 

 chloroform. 



2. The oxidation products from the chlorination and ozonation of waste and 

 cooling waters. These substances result from the interactions of bromine and 

 chlorine with organic molecules. Chloroform and chlorophenols are among the 

 products so far identified. 



3. Artificial radionuclides from the nuclear fuel cycle and from nuclear weapons 

 testing. This set includes the fission products (strontium-90, cesium-137), the 

 fuel materials and their alteration products (plutonium-239, plutonium-238, 

 americium-241), and the induced activities ( manga nese-54, cobalt-60). 



4. Biostimulants. the plant nutrients such as compounds of nitrogen, phosphorus 

 and silicon, trace metals, and dissolved organics that cause increased plant pro- 

 ductivity. As a consequence, alteration of the plant community structure and 

 possibly eutrophication of the waters can come about. 



5. Microorganisms, the agents of human and faunal disease, bacteria and 

 viruses. 



6. Trace metals that can inhibit plant and animal productivity or can make sea- 

 foods toxic. Attention has been draw n to lead, cadmium, copper, mercury, and 

 arsenic, among others. 



