14 



NOAA is also studying the presence of heavy metals in marine re- 

 sources and in fishery products. We are looking at over 200 species of 

 fish and shellfish to determine presence of such metals as mercury, 

 arsenic, cadmium, and chromium. Our findings to date indicate that 

 these elements are present in very low levels on the average. In the 

 few species where higher levels are found, all of our information shows 

 that such levels are closely associated with the larger fish of a species 

 and specific locations within their habitat. 



I am pleased to say this information has successfully provided the 

 basis for close industry and Government cooperation so that fish de- 

 livered to the American consumer meet public health requirements, 

 and are both a delicious and safe food. 



Senator Rollings. We had to take swordfish off the market, and 

 halibut. 



Dr. White. That is right. 



Senator Hollings. What has occurred as the result of those studies ? 



Dr. White. One of the reasons we are carrying out this study is we 

 believe if we can get adequate information, it is possible for us to 

 manage that type of a problem. In the case of halibut, what it has 

 done is set regulations on the take of halibut in certain sizes and cer- 

 tain areas. This insures that the fish coming to the table of the Ameri- 

 can cx)nsumer meets the FDA guidelines, and those fish that we know 

 exceed the guidelines are not taken. 



Now, we can do this if we know the distribution of these heavy metals 

 in various species of fish, where they are located, what the size rela- 

 tionship is to the concentration of heavy metals. So we can manage 

 these kinds of problems if we Iniow about them. 



Senator Hollings. How do you determine the causes of distribu- 

 tion? 



Dr. White. In the latter part of my testimony I get into the in- 

 teresting question of what is natural and what is manmade and what 

 we ought to do about it. 



In the case of mercury, most of it is not manmade, it is natural. It 

 has always been there. If you take a sample from the Smithsonian 

 Museum, taken a half century ago, and you examine it for mercury 

 content, what you will find is the mercury content of the fish that we 

 now take. 



Perhaps Dr. Aron would want to comment on this more specifically. 

 Most of the mercury in fish is natural. This is not to say there have 

 not been pools of very serious contamination due to industrial proc- 

 esses. We know where they are. 



Senator Hollings. Did we check it out in that area, too ? 



As I remember it, they had a large paper pulp mill down there. 



Dr. White. That is correct. 



Senator Hollings. I thought a doctor in Wisconsin was making tests 

 along that line. What occurred ? 



Dr. Aron. I think you will find, Mr. Chairman, that the commercial 

 fishing in the Great Lakes has been severely reduced by the concentra- 

 tion of mercury and also DDT contained by the concentration of mer- 

 cury and also DDT contained in the fishes, and the evidence is obvi- 

 ously for DDT is that this is manmade. Mercury does appear to be 

 the result of industrial discharges. 



Senator Hollings. IVIercury does not appear 



Dr. Aron. It does relate to the industrial discharge. 



