DDT residues in cod livers from the maritime provinces of Canada

Abstract

The residues of DDT and its analogs were estimated in a number of cod liver samples (Gadus morhua) collected at six sampling sites off the Atlantic Coast of the Maritime Provinces of Canada during the summer of 1971. The residue levels indicated widespread distribution of DDT over the entire region sampled. Variations in the relative contributions of p,p'-DDE and p,p'-DDT to the total DDT residues (xiDDT) were noted and the tendency for these residues to preferentially accumulate in lipid rich tissues was demonstrated. The residue levels found in cod livers were compared to the residue levels determined in cod flesh taken from some of the same specimens and also to residue levels in commercially refined cod liver oils. Samples of each of these types were stored at -29 degrees C and analyzed in 1973 for DDT and PCB simultaneously. The xiDDT residues determined by both methods of analysis were compared.

Organochlorine insecticide residues in deep sea fish from 2500 m in the Atlantic Ocean

“…Organochlorine residues in cod livers from the Atlantic coast of Canada determined by Sims et al (16,17) had a mean concentration of total DDT residues of 5.6 mg/wet kg compared with the mean concentration in the livers of Antimora rostrata of 7.05 mg/wet kg. The similarity of the mean concentrations is striking, since the cod inhabit relatively shallow continental shelf waters.…”

“…The similarity of the mean concentrations is striking, since the cod inhabit relatively shallow continental shelf waters. In the cod livers analyzed by Sims et al (16,17), there were increases in residues in fish that were collected from waters near large population centers such as Halifax, Nova Scotia. It would be possible to collect Antimora rostrata from 2500 m at various sites along the continental margin of the east coast of North America to determine whether or not population centers such as New York were affecting the concentration of residues in the fish on the adjacent deep sea.…”

“…Duke and Wilson (12) did not find PCBs to interfere with their quantitation of DDT and its metabolites in fish livers. Also, Sims et al (16) found that 2DDT analyses of cod fish tissues that had included compensation for the presence of PCBs gave results that were an average of 26% lower than analyses of aliquot samples not compensated for PCBs.…”