SEWAGE CONTAMINATION FOLLOWING AN ACCIDENTAL SPILLAGE IN THE RIA-FORMOSA, PORTUGAL

Following an accidental spillage of sewage to the Ria Formosa in Septe mber, 1994, sediment samples were collected and analysed for sterols a nd fatty alcohols. Coprostanol concentrations ranged from 0.1 mu g g(- 1) at sites remote from the spill, to 41.8 mu g g(-1) adjacent to the source. Use of the coprostanol/cholesterol ratio indicates the localiz ed nature of the dispersion, only 2 km from the source. The distributi on of fucosterol, ergosterol and fatty alcohols in the sediments are d iscussed. Principal Component Analysis using selected sterol and fatty alcohol ratios identified two major components describing the extent of sewage contamination and the marine-terrestrial nature of the organ ic matter. (C) 1997 Elsevier Science Ltd.