In order to more fully investigate the danger from pesticide pollution, several species of
fish and birds have also been examined. This examination has sometimes consisted of whole
body analysis. Animals are frequently dissected and the various body organs analyzed separately.
When body organs are separately analyzed a whole new picture emerges. One sample of mullet
contained 1 .149 ppm of DDT and its metabolites in the liver, .76 ppm in the gonads, 16 ppm in
the brain, and .346 ppm in the body flesh. Had this been prepared as a whole body sample, the
residue level would have been misleading.
This tissue or organ concentration causes much concern among biologists. Random sampling
results revealed that speckled sea trout had high concentrations in the liver and gonads, and some
bird samples have contained extremely high pesticide residues.
A peregrine falcon found dead on Padre Island contained 8.4 ppm of DDT residue in the brain
and 56 ppm in the liver. Another bird, a white pelican, found dead near Corpus Christi,
contained 84 ppm of DDT in the body flesh; 120 ppm in the liver; 18 ppm in the brain; 31 ppm in
the heart; and 16 ppm in the kidney. In addition, this same bird had over 2 ppm of Dieldrin in
most body tissues and 1 15 ppm and 1 14 ppm of polychlorinated biphenyl compounds in the body
flesh and liver, respectively.
The residues of DDT found in analysis of sea trout ovaries or eggs have ranged as high as 7.98
ppm. Liver from this species has contained as high as 9.3 ppm of DDT residue.
Evaluation of the data being amassed in this study indicates that the impairment of reproductive
ability and decrease in the survival of young are the greatest dangers to a species at the present
One researcher found that a species of fresh water trout fry hatching from eggs that contained
2.95 ppm or more of DDT would not survive. Another study has shown that one of the metabolites of DDT, DDE, has caused a change in the matabolism in birds that results in their
inability to produce firm eggshells. The result is thin or non-existent eggshells and a marked
increase in egg mortality before hatching can occur.
Evidence from data now being examined indicates that levels of DDT and other persistent
pesticides are high enough that, in some species and in some bay areas, significant but undetected increases in mortality have occured somewhere between the time the egg was fertilized
through the first few weeks of life.
CLEARING HOUSE, September, 1969
Grebe, Pied-billed: (1-3) 23, 26, 30, Cove, AKM.
Cormorant, Olivaceous: (2) 5, Cove, AKM.
Anhinga: (4) 7, Cypress Creek at Katy-Hockley Road, DHH.
Heron, Green: (6)5, (1 or 2) 5 days, Cove AKM.
Egret, Cattle: (40, 000+) 7, Warren Ranch Lake, DHH.
Reddish: (1) 5, 20, Cove, AKM.
Nightheron, Black-crowned: (1), 5, Cove AKM.
Yellow-crowned: (2) 5, 26, (1) 13, 27, Cove, AKM.
Stork, Wood: (8) 20, SE Houston (Gulf Freeway at Woodridge), NP.
Ibis, White-faced: (100+) 13, 20, (200) 19, (21) 27, Cove AKM.
White: (5) 13, (11) 27, Cove, AKM.
Spoonbill, Roseate: (6) 5, 13 (1-2) 19, 27, 30 (28) 20, Cove, AKM.
Treeduck, Fulvous: (About 130 in two flocks) 14, Katy area, MA & RM.
Duck, Mottled: (6-10) 3, 19, 27, (47) 5 (120) 13, Cove, AKM.
Pintail: (30) 30, Cove, AKM.
Teal, Blue-winged: (20) 13 (1-11) 20, 23, 26 (30) 30, Cove, AKM.
WIDGEON, AMERICAN: (2) 20(20) 27, Cove, AKM.
Shoveler: (3-5) 13, 20, Cove, AKM.
Hawk, Sharp-shinned: (1) 17, 19, Baytown, NB.
Red-shouldered: (1) 4 days (3) 13 (2) 14, Cove, AKM.
Swainson's: (1) 11, Cove, AKM.
Marsh: (1) 20, 30, Cove, AKM.
Osprey: (1) 14, San Jacinto Battleground, NB.
Hawk, Sparrow: (1) 11, 20, 23 (3) 26, 30, Cove, AKM.
Bobwhite: (4) 26, Cove, AKM.
Rail, King: (1) 9, Cove, AKM.
Coot, American: (16) 26, Cove, AKM.