Bryozoan Studies 2004 contains papers presented at the 13th International Conference of the International Bryozoology Association held in Concepci?n Chile in January 2004 and hosted by the Universidad de Concepci?n and Universidad Cat?lica de la Sant?sima Concepci?n. The topics presented include investigations in seven thematic areas: ecology and life strategies; recent and fossil faunas of Australia and New Zealand; past and present bryozoans from both Antarctic and Arctic seas; geo-logy and palaeontology of bryozoans from Eurasia and North America; fresh water bryozoans around the world; fossil bryozoans of the Mediterranean and Tethyan realms and, evolution and diversity of recent species.