The Pantanal ecoregional assessment relied on two experts' workshops to develop an aquatic ecological system classification and to select ecological system, natural community, and species conservation targets. During the workshops experts applied the TNC methodology for classifying aquatic sysems based on geology, geomorphology, hydrological regime, and biota (Higgins et al. 1998). Targets were selected based on this classification and know biological information during the second workshop. Coarse filter targets were selected largely based on the criteria of pristine vegetation, proximity to protected areas, and no roads or towns nearby. Fine filter targets were selected based on the criteria of rarity and endangerment. Keystone or umbrella species and natural communities were also considered.