Pesticides as tracers of sediment transport through Monterey Canyon

• DOI: 10.1007/s00367-002-0110-1
• Publication Date: 2003-02-13T03:25:53Z
• Authors: Paull C.; Greene H.; Ussler W.; Mitts P.
• Keywords: TRACER; Dilution; Submarine canyon

Residues of the pesticide DDT make an excellent tracer for following transport of fine sediment from coastal agricultural lands into the deep sea. The presence of DDT residues distinguishes those sediments which contain a component of terrestrially derived sediments which have accumulated since 1945, reveals the extent of mixing with DDT-free sediments, and establishes the depth to which sediments containing detectable DDT residues occur. A distinct trail of pesticide residue marks the axis of Monterey Canyon as the pathway for recent material transport from the continental shelf into the deep sea. 'Dilution' of the pesticides occurs primarily at the coastline, with little further 'dilution' occurring as the sediments move downslope into >3 km water depths.