13 



were in distress. Little evidence of damage to aquatic life was reported in 

 Concordia Parish, Louisiana [46], In Vermillion Parish, Louisiana, 150 sunfish 

 ( Lepomis ) of 3 species were found dead and 4 were seen alive; 41 individuals of 

 5 other species were found dead and none was seen alive; and 6 live individuals 

 of a ninth species were seen alive and none was found dead (Glasgow, letter). 

 In Hardin County, Texas, "fish kill was heavy and continued for over 3 weeks. 

 Young fish died first. The few survivors were usually large and, except for 

 shad and gambusia, were thin. Two months after the poisoning, larvae of several 

 species were found, and the population of fishes appeared to be on the way to 

 recovery. During a later treatment of the southern part of the farm, extreme 

 care was taken to avoid contamination of water with heptachlor, and a fish kill 

 was avoided" [4], 



Bureau personnel studying fish ponds near Quincy, Florida (Frey, unpubl.) 

 found mortality to bluegill and black bass in 2 ponds exposed to 0.25 pound of 

 technical heptachlor per acre in granules. Three other adjacent ponds sub- 

 jected to the same treatment had no immediate fatalities, but their fish popu- 

 lations are being studied for signs of damage. 



In Florida, dieldrin treatment at 1 pound per acre in granular form (used 

 in sandfly control) virtually eliminated fish in a salt marsh area [30]. 

 Tarzwell [61] reports 0.07 pound of dieldrin or 0.16 pound of heptachlor per 

 acre is sufficient to produce a 50^ kill of fish in 96 hours, with concentra- 

 tions of 7.9 and 19 parts per billion, respectively, being sufficient to kill 

 bluegiils in the laboratory. Toxicity varies with species and environments. 



Studies to date, therefore, indicate that dieldrin produces heavy kills 

 and heptachlor can produce substantial kills where the granules enter the water, 

 but quantitative figures are lacking as to the total population effect. The 

 Alabama and Texas studies would indicate that recovery of a population begins 

 during the first year after treatment. 



h. Effects on Aquatic Invertebrates . In the Wilcox County, Alabama, 

 area water insects and crayfish were found dead within 14 hours after treatment 

 and continued to die for at least 40 hours [2], (Baker, unpubl.). Many dead 

 crayfish were found in St. Landry Parish, Louisiana [29], (Glasgow, unpubl.). 



i. Effects on Earthworms and Terrestrial Insects . Earthworms, a 

 major food item for woodcock and robins, contained up to 20 parts per million 

 of heptachlor epoxide in their tissues 6 to 10 months after treatment of land 

 in St. Landry and Acadia Parishes, Louisiana. In Wilcox County, Alabama, 

 earthworms collected 1 year after application of insecticide contained 1 part 

 per million of heptachlor epoxide in their tissues. The average heptachlor 

 epoxide content of 32 samples, containing up to 100 earthworms per sample, 

 taken 6 to 12 months after treatment in areas receiving 2 pounds of heptachlor 

 per acre, was 3 parts per million (Table 14). 



In Union County, Arkansas, there were 40^ fewer insects of all types in 

 treated than in untreated soil sampled 1 year after application of insecticide 

 (Boyer, unpubl.). 



