1. Methodology and New Developments.- Applications and performance of Radio-Acoustic Positioning and Telemetry (RAPT) systems.- A comparison of theoretical estimates of the errors associated with ultrasonic tracking using a fixed hydrophone array and field measurements.- Selection of optimal positioning intervals in fish tracking: an experimental study on Barbus barbus.- Inland migration study of sea trout (Salmo trutta) into the rivers Rhine and Meuse (The Netherlands), based on inductive coupling radio telemetry.- Development of miniature pingers for tracking Atlantic salmon smolts at sea.- A dynamic combined acoustic and radio-transmitting tag for diadromous fish.- Frequency choice for radio telemetry: the HF vs. VHF conundrum.- Simultaneous observations of tuna movements and their prey by sonic tracking and acoustic surveys.- A data logger tag for the study of slaughter procedures in aquacultured salmon.- 2. Tagging Procedures.- Growth and physiological responses to surgical and gastric radio transmitter implantation techniques in subyearling chinook salmon (Oncorhynchus tshawytscha).- Use of miniature radio-transmitters to track the movements of dace, Leuciscus leuciscus (L.) in the River Frome, Dorset.- The effects of Passive Integrated Transponder tags on survival and growth of juvenile brown trout (Salmo trutta L.) and their use for studying movements in a small river.- Evaluation of surgery procedures for tagging eel Anguilla anguilla (L.) with biotelemetry transmitters.- A method for the external attachment of acoustic tags on roundfish.- Regurgitation rates of intragastric transmitters by adult Atlantic salmon (Salmo salar L.) during riverine migration.- 3. Behavioural and Physiological Ecology.- New approaches to the behavioural ecology of decapod crustaceans using telemetry and electronic tags.- Electromagnetic telemetry of lobster (Homarus gammarus (L.)) movements and activity: preliminary results.- Basic movement pattern and chemo-oriented search towards baited pots in edible crab (Cancer pagurus L.).- Telemetry applied to behaviour analysis of yellowfin tuna (Thunnus albacares, Bonnaterre, 1788) movements in a network of fish-aggregating devices.- Spawning migration of radio-tagged landlocked Arctic Charr, Salvelinus alpinus L. in Ennerdale Lake, the English Lake District.- Acoustic tracking of the dispersal of organic matter by scavenging fishes in the deep-sea.- Seasonal variations in time and space utilization by radio-tagged yellow eels Anguilla anguilla (L.) in a small stream.- Reactions of cod (Gadus morhua L.) in the pre-vessel zone to an approaching trawler under different light conditions: preliminary results.- Changes in vertical distribution of sea bass (Dicentrarchus labrax L.) during a hypoxic episode.- Heart rate telemetry to study environmental influences on fish metabolic expenditure.- Effects of thermal environment on electromyographical signals obtained from Atlantic salmon (Salmo salar L.) during forced swimming.- Remote monitoring of heart rate as a measure of recovery in angled Atlantic salmon, Salmo salar (L.).- Using speed-sensing transmitters to construct a bioenergetics model for subadult lemon sharks, Negaprion brevirostris (Poey), in the field.- 4. Fish Migration and Stock Management.- Migratory and reproductive activity of radio-tagged Arctic char (Salvelinus alpinus L.) in northern Labrador.- Environmental unpredictability rules the autumn migration of brown trout (Salmo trutta L.) in the Belgian Ardennes.- Spawning migration of sea trout (Salmo trutta (L.)) in a Danish river.- A radio telemetry study of the migration of Atlantic salmon (Salmo salar L.) and sea trout (Salmo trutta trutta L.) in the upper Rhine.- The migratory behaviour of wild Atlantic salmon (Salmo salar L.) smolts in the River Test and Southampton Water, southern England.- Movements of a bream (Abramis brama (L.)), rudd x bream hybrid, tench (Tinca tinea (L.)) and pike (Esox lucius (L.)) in an Irish canal habitat.- Radio telemetry as a tool to study habitat use of nase (Chondrostoma nasus L.) in medium-sized rivers.- The migratory behaviour of juvenile and adult salmonids in relation to an estuarine barrage.- Movements of adult sea trout Salmo trutta L. in the tailrace of a low-head dam at W?oc?awek hydroelectric station on the Vistula River, Poland.- Migration of adult Atlantic salmon (Salmo salar (L.)); the effects of artificial freshets.- Survival of radio-tagged Atlantic salmon (Salmo salar (L.)) and trout (Salmo trutta L.) smolts passing a reservoir during seaward migration.- The efficiency of a nature-like bypass channel for pike-perch (Stizostedion lueioperca (L.)) in the Marchfeldkanalsystem.