BUTYLTINS IN SEDIMENTS FROM SANTA-MONICA AND SAN-PEDRO BASINS, CALIFORNIA

Butyltins have been measured for the first time in sediments from the deeper waters of the Santa Monica and San Pedro (SM/SP) basins of Sout hern California borderland. Core samples were collected from water dep ths ranging from 458 m in the shelf to 906 m in the central basin. Sur ficial and a few subsurface sections from selected cores were analyzed for butyltins. The dominant components are generally dibutyl and mono butyltins (DBT and MET, respectively). Microbial degradation of Tribut yltin (TBT, the most toxic of the butyltin species) to DBT and MBT dur ing the long range transport to deeper basins, as well as a lack of co ntinuing inputs of TBT in the present times could justify the butyltin s signatures found in the region. The levels of butyltins are in the l ower range (below detection level, < 1, to 14 ng of Sn g(-1)) relative to nearshore sediments. However, the results demonstrate that the but yltins are, indeed, found even in the sediments of the central basins of the Southern California borderland suggesting that deeper global oc eanic regimes need to be further investigated for these compounds. (C) 1998 Elsevier Science Ltd. All rights reserved.