Heavy metals distribution in superficial sediments of Maracaibo Lake (Venezuela)

ni, v, cr, cd, cu and pb were determined in superficial sediment samples from system maracaibo lake. thirteen sampling points were sampled in tablazo bay, maracaibo strait and maracaibo lake, four times during 2 years as follows: october 1999 (rainy season), march 2000 (dry season), november 2000 (rainy season) and may 2001 (low rainy period). mean values (minimum-maximum) of heavy metals were: cu: 27,07 (2,31-75,46), cd: 3,37 (0,46-7,9), cr: 39,50 (3,98-98,28), pb: 60,59 (17,8-143,9), v: 50,44 (1,29-121,2) y ni: 65,31 (16,76-177,62) mg.kg-1. the metal concentrations present in sediments were in the following order: ni>pb>v>cr>cu>cd. metal concentration in sediments of maracaibo lake system, are similar to the aquatic systems with a high oil activity. samples showed a clear tendency to higher values in the eastern area of maracaibo lake and lower value in the western zone.