[en] The IAEA Marine Environment Laboratory (IAEA-MEL), formerly known as the International Laboratory for Marine Radioactivity (ILMR) was founded thirty years ago. This article provides a brief historical review of the activities of the IAEA-MEL, focussing on the monitoring of pollution in the Mediterranean Sea. The contamination arising from the Chernobyl accident is discussed, and data on the distribution of pesticide residues in mussels along the northern Mediterranean cost are presented. A collaborative project with the National Autonomous University of Mexico to study pesticides in the Altata lagoon is described. 25 refs, 7 figs, 1 tab