Movements and aggregation areas of adult Atlantic sturgeon (Acipenser oxyrinchus) in the St Lawrence River estuary, Quebec, Canada

Re´jean Fortin died prematurely in September 2001.He was an excellent scientist having a keen eye for natural facts and events and an excellent pedagogue who turned out several graduate students in fisheries science.His contribution to the knowledge of Lake sturgeon (Acipenser fulvescens) biology and management will remain pertinent for future decades.Re´jean was also a great colleague and a great friend SummaryIn 1998 and 1999, 49 adult St Lawrence River Atlantic sturgeon (Acipenser oxyrinchus) were equipped with ultrasonic transmitters and tracked during the summers of 1998-2000 with the objective of studying movements and identifying aggregation and spawning areas.The 3 years of study led to the localization of six adult aggregation areas, four in freshwater and two in brackish water.Three of the freshwater aggregation areas (Richelieu Rapids, Saint-Antoinede-Tilly and the mouth of the Chaudie`re River) were identified as potential spawning areas.The three other aggregation areas (Saint-Charles River estuary, Traverse du Milieu Channel and the northern channel between Sault-au-Cochon and Petite-Rivie`re-Saint-Franc¸ois) were identified as feeding and/or resting areas.Telemetry and gillnetting results suggest that St Lawrence River Atlantic sturgeon spawning occurs between early June and mid-July, within the 14.5-23.4°Cwater temperature range.Mean daily distances traveled were 13.7 ± 20.8 km (n ¼ 77) and mean travel speeds were 1.6 ± 1.7 km h )1 (n ¼ 88).Adult sturgeon locations were generally from sites deeper than 10 m at low tide.Management implications of these results are discussed.