This volume provides a selection of papers presented at the Second Conference on Fish Telemetry in Europe in La Rochelle, France, in April 1997. The conference was attended by 100 scientists from 18 countries. The contributions are grouped under the following headings: Methodology and New Developments, Tagging Procedures, Behavioural and Physiological Ecology, Fish Migration, Stock Management and Conservation. Particular emphasis was put on tag miniaturization, multiple functions and sampling strategies. Papers concerned the effects of tags on fish for consolidating behavioural or original physiological investigations noticeably more open to the marine environment. Methods were essentially applied to study the relationships between fish and their natural environment. Besides providing information on the state of fish telemetry in the late 1990s, this text illustrates the increase in spatial and temporal scales and the number of tracked fish, giving a statistical basis for field study in behavioural ecology.