350 



Construction and demolition debris, consisting of masonry, tile, stone, wood 

 and plastics, excavation dirt, and the like, is dumped in significant quantities in 

 the oceans near some U.S. municipal areas, but is generally thought to contain 

 inert and non-toxic substances. Other solid municipal wastes, however, may con- 

 tain appreciable quantities of nutrients, oxygen-demanding materials, and heavy 

 metals. These wastes also contain a large proportion of paper, wood, plastics 

 and rubber, which may rise to the surfoce and create safety and aesthetic prob- 

 lems. Only a small portion of solid municipal wastes is presently dumped at sea ; 

 however, the CEQ anticipated that the u.se of the oceans as receptacles for these 

 wastes is likely to increase substantially as land disposal becomes more costly 

 and politically inexpedient. 



Munitions, including un.serviceable or obsolete shells, mines, rocket fuels and 

 propellants, have been dumped at sea in significant quantities since World War 

 II, often in scuttled Liberty ships. Such devices contain amounts of lead, nickel, 

 bronze and other potentially toxic metals, as well as potentially toxic undetonated 

 highly-reactive explosives. 



Finally, the oceans have been used, to a moderate degree since World War II, 

 as dumping grounds for nuclear waste products, although the U.S. in recent 

 years has confined such dumpings to a minimum. Moreover in recent years, the 

 volume of dumped radioactive materials has sharply declined as land disposal 

 methods have been developed and increasingly relied upon. Dumped wastes have 

 included liquid products of low radioactivity, including processing and cooling 

 waters from reactor operations, and solid wastes produced by nuclear contamina- 

 tion and medical and research uses. 



Ocean-dumped wastes of all kinds are primarily dumped in bulk, or in con- 

 tainers which are sunk by weighting or rupturing at the surface. In U.S. dumping 

 sites, dredge spoils are typically dumped in relatively shallow waters within a 

 few miles of the coast, indu.strial and municipal wastes from 15 to 100 miles 

 offshore, and radioactive and explosive wastes in areas with depths of 6,000 

 feet or more. 



2. General Environmental Effects. — The environmental effects of the dumping 

 at sea of the.se waste materials are not yet fully known. However, there is broad 

 agreement that unrestricted dumping presents a potentially serious threat to 

 marine life systems and to human uses of marine resources. 



a. Implications for marine life 



Toxicity. — Fish and other marine organisms are sometimes killed directly by 

 ingestion of or contact with lethal concentrations of toxic heavy metals or persist- 

 ent organics in dumped material. Even more serious, however, are the sublethal 

 effects on marine life of the dumping of toxic and irritant substances. The pres- 

 ence of such materials may interfere with chemo-receptor mechanisms, reduce 

 resistance to stress and infection, and interfere with respiratory and filtering 

 organs. These effects may be particularly serious for higher predators as a result 

 of biological concentrations of toxic substances contained in organisms on which 

 they feed. Furthermore, many of these substances are believed to have carcino- 

 genic effects on marine life forms. 



Oxygen Depletion. — Organic wastes, sulfides, and some metals, when dumped 

 into the ocean, require oxygen during decomposition. As a result, the dumping 

 of these wastes in bodies of water tends to deplete the oxygen supply necessary 

 for the support of marine life. Furthermore, the death of organisms from oxygen 

 depletion may lead to the production of malodorous hydrogen sulfide and methane 

 gas by anaerobic bacteria. Some materials require large amounts of oxygen 

 during decomposition, and may continue to deplete dissolved oxygen in 

 a marine area long after it is dumped. 



Biostimulation. — Wastes rich in such nutrients as phosphates and nitrates 

 may cause biostimulation, or accelerated growth of algae and other plant life, 

 or it may selectively stimulate undesirable s^x'cies. Excessive plant gro\A-th may 

 lead to oxygen depletion during decomposition, the deposit of rotting algae on 

 beaches, and the disruption of bottom-dwelling organisms by deposits of algal 

 mud. 



Changes in Hahitat. — The dumping of wastes may also cause physical changes 

 in bottom sediments which disnipt and later marine eco.systems. Sewage sludge 

 and polluted dredge si)oil.s in particular, have l)een found to cause such changes 

 in the characteristics of bottom layers as to obliterate certain life forms in the 

 dumi)ing area or to upset the ecological balance of the area by stimulating otlier 

 life forms. 



Shock. — Finally, marine organisms, particularly those with swim bladders, 

 may be killed by shock waves from the detonation of dumped munitions. 



