Movements and biological statistics of lake sturgeon (Acipenser fulvescens) populations from the St. Lawrence and Ottawa River system, Quebec

Abstract

Our objective was to compare movements and biological statistics of lake sturgeon (Acipenser fulvescens) populations from two fluvial lakes on the St. Lawrence River, Lac Saint-Louis and Lac Saint-Pierre, which are main commercial fishing sectors, and from Lac des Deux Montagnes on the Ottawa River. Sturgeon can move freely among these three lakes. Lac des Deux Montagnes sturgeon differ from the other groups by their higher degree of sedentariness, slower growth, and lower condition factor. Lac Saint-Louis and Lac Saint-Pierre sturgeon are also sedentary, but some movement between the two lakes was observed. Sturgeon tagged on the Rivière des Prairies and Rivière L'Assomption spawning grounds, located in the central part of the study area, and also on pre- and post-spawning concentration sites, were recaptured throughout the St. Lawrence River, from Lac Saint-Louis to Lac Saint-Pierre. Length, weight, and age composition of the commercial catch, growth, and total mortality varied between Lac Saint-Louis and Lac Saint-Pierre. Higher commercial exploitation rates in the latter could be responsible for some differences. The management implications of these results are discussed.

Reintroduction of Lake Sturgeon (Acipenser fulvescens) into the St. Regis River, NY: Post- Release Assessment of Habitat Use and Growth

“…Inherited traits such as morphology, life history and/or behaviour also can be used to support designatable units under this criterion. Unfortunately, appropriate studies across the geographic range of lake sturgeon are also lacking; however, Fortin et al (1993) suggested that populations probably differ by watershed and that there also may be differentiation of sympatric populations in larger watersheds, a suggestion consistent with the results of the genetic studies cited above.…”

“…This may be explained by the greater longevity of females (Probst and Cooper 1954;Dumont et al 1987). Fortin et al (1993) found that by the age of maturation (20-29 years) in southern Quebec, the female:male ratio was in the order of 2:1 and by age 40, it was 6:1. Mosindy and Rusak (1991) found a similar increase in Lake of the Woods.…”

“…The sex ratio is more or less 1:1 at birth but, following maturation, begins to widen in favour of females (Mosindy and Rusak 1991;Fortin et al 1993). This may be explained by the greater longevity of females (Probst and Cooper 1954;Dumont et al 1987).…”

“…In the Quebec part of the St. Lawrence River, mark-recapture experiments indicate that, with the exception of spawning migrations which are extensive, movements are restricted (Magnin and Beaulieu 1960;Dumont et al 1987;Fortin et al 1993). In this system, lake sturgeon occur in large numbers in small localized sites, and this condition increases their vulnerability to fishing and to any degradation of these local habitats (filling, dredging, toxic outflows, etc.).…”

Movement of Lake Sturgeon, <em>Acipenser fulvescens</em>, in a Natural Reach of the Ottawa River

“…Homing or site fidelity by Lake Sturgeon has previously been described (Threader and Brousseau 1986;Fortin et al 1993;Rusak and Mosindy 1997;Auer 1999;Caswell et al 2004). This area of the river is characterized by a sandy, clay substrate, which should be productive for benthic invertebrates, the primary source of prey for sturgeon.…”