It was inevitable that s erious des truction of fis hes would follow the wides pread us e of the new
organic pesticides.
Fishes are almost fantastically sensitive to the chlorinated hydrocarbons that make up the bulk
of mode rn ins ecticides. And when millions of tons of pois onous chemicals are applied to the
surface of the land, it is inevitable that some of them will find their way into the ceaseless cycle
of waters moving be tween land and sea. Reports of fis h kills , s ome of dis as trous proportions ,
have now become s o common that the United States Public Health Service has s et up an office
to collect s uch reports from the s tates as an index of water pollution. This is a problem that
concerns a great many people. Some 25 million Americans look to fishing as a major source of
recreation and another 15 million are at least casual anglers. These people spend three billion
dollars annually for licenses, tackle, boats, camping equipment, gasoline, and lodgings.
Anything that deprives them of thei r s port will als o reach out and affect a large numbe r of
economic interests. The commercial fisheries represent such an interest, and even more
importantly, an essential source of food. Inland and coastal fisheries (excluding the offs hore
catch) yield an estimated three billion pounds a year. Yet, as we shall see, the invasion of
s treams , ponds , rivers , and bays by pes ticides is now a threat to both recreational and
commercial fishing.
Examples of the des truction of fis h by agricultural crop s prayings and dus tings are everywhere
to be found. I n California, for example, the loss of some 60,000 game fish, mostly bluegill and
othe r s unfis h, followed an attempt to control the riceleaf miner with dieldrin. In Louisiana 30 or
more ins tances of heavy fis h mortality occurre d in one year alone (1960) becaus e of the us e of
endrin i n the s ugarcane fields. In Penns ylvania fis h have been killed in numbe rs by endrin, us ed
in orchards to combat mice. The us e of chlordane for gras s hopper control on the high wes tern
plains has been followed by the death of many s tream fis h. Probably no other agricultural
prog ram has been carried out on s o large a s cale as the dus ting nd s praying of millions of ac res
of land in s outhern Unite d States to control the fire ant. Heptachlor, the chemical chiefly us ed,
is only slightly less toxic to fish than DDT. Dieldrin, another fire ant poison, has a well-
documented his tory of extre me hazard to all aquatic life. Only endrin and toxaphe ne re pres ent
a greater danger to fis h. All areas within the fire ant control area, whether treated with
heptachlor or dieldrin, reported dis as trous effects on aquatic life. A few excerpts will give the
flavor of the re ports from biologis ts who s tudied the da mage: From Texas, ‘Heavy los s of
aquatic life despite efforts to protect canals’, ‘Dead fish...were present in all treated water’,
‘Fish kill was heavy and continued for over 3 weeks’. From Alabama, ‘Most adult fish were killed
[in Wilcox County] within a few days after treatme nt,’ ‘The fis h in tempora ry waters and s mall
tributary s trea ms appeared to have been completely eradicated.’
In Louis iana, farmers complained of loss in farm ponds. Along one canal more than 500 dead
fish were seen floating or lying on the bank on a stretch of less than a quarter of a mile. In
anothe r pa ris h 150 dead s unfis h could be found for every 4 that remained alive. Five other
s pecies appeared to have been wi ped out completely. I n Florida, fis h from ponds in a treated
area were found to contain res idues of heptachlor and a de rived che mical, heptachlor e poxide.
Included among thes e fis h were s unfis h and bass , which of cours e are favorites of anglers and
commonly find their way to the dinner table. Yet the che micals they contained are among thos e
the Food and Drug Adminis tration cons iders too dangerous for human cons umption, even in
minute quantities. So extens ive were the re ported kills of fis h, frogs , and othe r life of the
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