ANALISIS DE RESIDUOS DE ORGANOCLORADOS EN LOS SEDIMENTOS DE ZONAS DE MANGLAR EN LA CIENAGA GRANDE DE SANTA MARTA Y LA BAHIA DE CHENGUE, CARIBE COLOMBIANO

Abstract

Concentrations of six organochlorine pesticide residues (lindane, heptachlor, aldrin, pp 'DDE, pp'DDD y pp'DDT) were analized in surface mangrove sediments at four sites at Ciénaga Grande de Santa Marta and in one site in Bahía de Chengue, Colombian Caribbean. Analyses were carried out by gas-liquid chromatography. Samples were taken between March and December 1993, corresponding to four climatic seasons (dry, minor rainy, minor dry and major rainy). Significant differences in lindane, heptachlor and pp'DDE concentrations among seasons were determined by multifactorial analysis of variance; the other three compounds(aldrin, pp,DDD an pp 'DDT) did not show significant differences for any of the likely sources of variation. Highest concentrations of lindane were in dry season and those of heptaclore and pp'DDE were in rainy season. A canonical correlation was run between the groups formed with organochlorine concentratios and water salinity plus relative organic matter content. The correlation coefficients indicate that only pp'DDT presented a inverse correlation with the percentage of organic matter.