134 



Atomic Radiation and Oceanography and Fisheries 



isms at different trophic levels, over a large 

 sea area at intervals of approximately 4 months 

 and 13 months after the test. 



These observations have been directed pri- 

 marily to possible human hazards through con- 

 tamination of edible marine products. Only 

 minor attention has been given to ecological 

 processes, probably because of lack of facilities 

 for the extensive, systematic collecting required. 



Soon after the underwater test in the Eastern 

 Pacific in the spring of 1955, some collections 

 were made that indicate which organisms in the 

 food chain are the primary concentrators of 

 certain radioisotopes, and that give some indi- 

 cation of the time scale in passage to the next 

 step of the food chain. Unfortunately, it was 

 not possible to follow the passage of isotopes 

 farther through the system. 



Following a weapons test a series of obser- 

 vations and collections taken in a carefully 

 planned pattern in space and time could pro- 

 vide information on the time scale involved in 

 the passage of material through the system of 

 prey and predators, and on the efficiency of this 

 transfer from one stage to another, two of the 

 little understood basic problems in marine ecol- 

 ogy. Data from experiments with radioactive 

 tracers, together with more limited field data, 

 indicate that the transfer efficiencies are differ- 

 ent for different elements. 



In those situations, following weapons tests, 

 where there is a fairly extensive body of water 

 containing radioisotopes at some particular level, 

 say at the surface, it should be possible by means 

 of collections at various depths over a period 

 of time to obtain worthwhile information on 

 the vertical migrations of organisms, and also 

 to determine how the feeding and excretion 

 patterns of such organisms transport radioiso- 

 topes from one level to another. 



These and similar studies would require the 

 assignment of a vessel, with necessary equip- 

 ment and a team of scientists, to the exclusive 

 pursuit of such studies. Since results will de- 

 pend on systematic, serial observations, the ves- 

 sel must be available to take them when and 

 where required, which precludes the commit- 

 ment of the vessel to other activities. Although 

 a sizable cost is involved, it is believed that the 

 results to be obtained are of sufficient value to 

 more than justify it. 



It should also be pointed out that effective 

 planning of such studies requires considerable 



knowledge of the types of organisms to be en- 

 countered in the test area, the sizes of their 

 populations, and some knowledge of their mi- 

 gration patterns, as well as data on the currents 

 and other physical parameters to be considered. 

 A pre-survey of the test areas by standard 

 methods of biological investigation is, therefore, 

 an important element in the adequate planning 

 and execution of post-test investigations by 

 means of the radioisotopes produced by the 

 test. 



Observations in connection ivith waste disposal 



The disposal of wastes from the fission in- 

 dustry by introduction into the marine en- 

 vironment offers another means of studying 

 the uptake of elements by aquatic organisms, 

 their fluxes in the ecosystem, and their effects 

 on the organisms concerned. Advantages over 

 weapons tests are: (1) the wastes are usually 

 introduced in such a manner that their amount, 

 distribution and physical state can be readily 

 determined, (2) disposal is usually continuous, 

 even though not of constant magnitude, thus 

 permitting systematic study over considerable 

 periods of time. 



Disposal in the United States has consisted 

 of relatively low-level wastes introduced into 

 fresh waters by the Hanford works on the 

 Columbia River, the Oak Ridge National Lab- 

 oratory, and the Plant on the Savannah River. 

 At the first named locality, field observations, 

 supplemented by laboratory experiments, are 

 being made on the uptake of radioisotopes by 

 organisms, their fluxes through the food chain, 

 and their distribution in the river as the result 

 of the combined effects of physical and bio- 

 logical processes. The phosphorous cycle has 

 been investigated in particular detail. At the 

 Oak Ridge Laboratory, observations were made 

 over a period of years on the uptake of fission 

 products by various organisms, the sites of 

 deposition of radioisotopes in the organisms 

 and the effects on some of their populations. 

 Continuous disposal into marine waters is not 

 practiced at present in this country. Reports 

 by H. Seligman, H. J. Dunster, D. R. R. Fair 

 and A. J. McLean at the 1955 Geneva Con- 

 ference on Peaceful Uses of Atomic Energy 

 describe introduction of low-level wastes into 

 the Irish Sea, and briefly review studies of the 

 uptake of various isotopes by different kinds of 

 organisms. 



