MARINE DECOMPOSITION Persistence of carbaryl in the marine estuarine environment. Chemical and biological stability in aquarium systems

Abstract

Colorimetric and radiometric analyses have been used to study the persistence of carbaryl in estuarine water and mud in laboratory aquaria held at two temperatures. In the absence of mud, the carbaryl concentration decreased approximately 50% in 38 days at 80 C. Most of this decrease was accounted for by the production of 1-naphthol.At 20°C. after 17 days, the carbaryl had almost completely disappeared, with 43 % converting to 1-naphthol. When mud was present, both carbaryl and 1-naphthol declined to less than 10% in the sea water in 10 days. Both compounds were adsorbed by the mud, where decomposition continued at a slower rate. Radioactive carbon dioxide was produced in the aquaria containing 14C carbonyl-labeled and 14C ring-labeled carbaryl, indicating decomposition by hydrolysis of the carbamate and oxidation of the naphthyl ring. The total recovery of the 14C activity was only 40%. It is postulated that much of the remainder was evolved as methane. In a preliminary field experiment in which a portion of a mud flat was treated with carbaryl at rates similar to those used in the control of pests of oyster beds, carbaryl could be detected in the mud for 42 days. 1-Naphthol persisted in significant quantities for only one day.

Carbaryl: A Literature Review

“…KARINEN et al (1967) found that laboratory estuarine environments containing mud decreased carbaryllevels by 80% 10 days after addition of carbaryl. This compares with a 50% decrease by 38 days after carbaryl addition to sea water not containing mud.…”

“…KARINEN et al (1967) found that carbaryl degraded slowly and persisted for several wk at low temperatures under laboratory conditions where absorption by bottom mud was prevented. Under these conditions one of the decomposition products of carbaryl was I-naphthol, which was further degraded by the action of light.…”

“…It has been extensively used for the control of ectoparasites on poultry (ZIV et al 1977) including its use to control chicken mites and lice, as weIl as bedbugs, northern fowl mites, and fleas (Union Carbide Corporation). 1t has also been used to control the pests and predators of oysters, such as oyster drills, ghost or mud shrimp, and pea crabs (ANDREWS 1968, KARINEN et al 1967, HAVEN et al 1966, HAYDOCK 1964, SNOW and STEWART 1963, LINDSAY 1961.…”

“…Marine organisms are capable of degrading carbaryl and I-naphthol. KARINEN et al (1967) indicated 1-naphthol was more susceptible to degradation by marine microorganisms than was carbaryl. Filamentous fungi possess a greater ability to degrade I-naphthol than bacteria and yeast (SIKKA et al 1975).…”

Accumulation Pattern of Pesticides in Tropical Fresh Waters

“…The water fraction showed continuous depletion, while in sediment there was first a build up and then a rapid dissipation, folowed by a slower step which coincided with the stationary phase in water. Karinen et al (1967) had noted an initial increase in carbaryl content as it slowly dissolved in the water sample. This step was not observed in this study perhaps because of solubility behaviour of the formulation used.…”