DISTRIBUTION AND ASSOCIATION OF TRACE-METALS IN SOFT-TISSUE AND BYSSUS OF MYTELLA-STRIGATA AND OTHER BENTHAL ORGANISMS FROM MAZATLAN HARBOR, MANGROVE LAGOON OF THE NORTHWEST COAST OF MEXICO

Concentrations of Cd, Pb, Zn, Cu, Ag, Cr, Co, Ni, Mn, and Fe in soft t issues and byssal threads of Mytella strigata (Mytilidae) and other be nthal organisms (clam Chione subrugosa and algae Enteromorpha intestin alis, Ulva lactuca) from four sampling sites in a tropical mangrove la goon, on the northwest coast of Mexico, were determined by atomic abso rption spectrophotometry (AAS). Some inter-regional differences in met al concentrations, especially concerning Ni, Cu, and Mn in both soft t issue and byssus, were identified. The concentrations of the majority of the metals analyzed were significantly greater in byssus than in so ft tissue, even as great as an order of magnitude for Pb, Co, Cr, Ni, Mn, and two orders of magnitude for Fe. Significant correlations (p<0. 01; p<0.05) were observed between tissue concentrations of Ni-Mn, Cu-N i (positive), Pb-Ni, Pb-Mn, Mn-Fe (negative) as well as byssal concent rations of Pb-Cr-Fe, Cu-Zn-Mn (positive), Pb-Ni, Ni-Fe, Cd-Zn (negativ e). Inter-comparison of the present data with those published previous ly (for Mytilidae from Japanese and Yemeni coastal waters) indicates t hat the soft tissue (mainly for Cd) and byssus (especially for Co, Ni) are useful in detecting areas of selected metallic contaminants. Moll uscs such as M. strtigata and C. subrugosa appear to be convenient bio monitors for identification of coastal waters exposed to Cd, Pb, Cu, Z n, Cr, Co, Ni, Mn, and Fe in the tropical American region. (C)1998 Els evier Science Ltd.