The 5th International Symposium on Inland Saline Lakes was held at Hotel Titikaka on the shores of that lake, 22-29 March 1991 with participants from 16 countries. 23 papers presented by the participants, plus an additional one reporting a microcosm study on salinity effects, constitute the present volume. The papers cover the wide array of subject matters and scales characteristic of our "interdiscipline" and represent the symposium.