Length–weight relationship and a relative condition factor equation for lake sturgeon (Acipenser fulvescens) from the St Clair River system (Michigan, USA)

Summary Several USA state, federal, and Canadian agencies study lake sturgeon (Acipenser fulvescens) within the St Clair River and Lake St Clair, collectively referred to hereafter as the St Clair River (SCR) system. Previously, there has been no set standard for determining condition for SCR system lake sturgeon. Condition measures the variation from the expected weight for length as an indicator of fatness, general well-being, gonad development, etc. The aim of this project was to determine the length–weight relationship of lake sturgeon caught from the SCR system, from which a relative condition factor (Kn) equation could be derived. Total length (TL, mm) and weight (W, kg) were measured for 1074 lake sturgeon (101 males and 16 females were identifiable) collected by setline and bottom trawl from the SCR system in May–September, 1997–2002. Analysis of covariance found no difference in the length–weight relationship between sampling gear or sex. Least-squares regression of log10W × log10TL produced the overall equation logW = 3.365logTL − 9.320. Using the exponential form of the slope and y-intercept, relative condition factor for lake sturgeon from the SCR system can be calculated as Kn = W/[(4.786 × 10−10)(TL3.365)]. Equations for males and females were also developed. Overall, body condition was significantly correlated with both age and girth; no significant difference in Kn by sex was found. In general, the SCR lake sturgeon population was near the upper ends of growth and condition ranges listed in the literature, comparable with those populations that are at similar latitudes. Although condition factors should be interpreted with caution, proper use of a standard equation provides a non-lethal measure of overall fish health that can be used by biologists and managers in ongoing efforts to restore lake sturgeon throughout the Great Lakes.

[1]  D. Noakes,et al.  A Noninvasive Technique for Determining Sex of Live Adult North American Sturgeons , 2003, Environmental Biology of Fishes.

[2]  G. Power,et al.  Seasonal migrations and reproductive patterns in the lake sturgeon, Acipenser fulvescens, in the vicinity of hydroelectric stations in northern Ontario , 1998, Environmental Biology of Fishes.

[3]  G. Moberg,et al.  Observations on the reproductive cycle of cultures white sturgeon, Acipenser transmontanus , 1997, Environmental Biology of Fishes.

[4]  Michael V. Thomas,et al.  Assessment of lake sturgeon ( Acipenser fulvescens ) spawning efforts in the lower St. Clair River, Michigan , 2003 .

[5]  Michael V. Thomas,et al.  Abundance, age structure, and spatial distribution of lake sturgeon, Acipenser fulvescens, in the St Clair System , 2002 .

[6]  R. Bruch,et al.  Spawning behavior of lake sturgeon (Acipenser fulvescens) , 2002 .

[7]  Stephen G. Sutton,et al.  Relationships among Fat Weight, Body Weight, Water Weight, and Condition Factors in Wild Atlantic Salmon Parr , 2000 .

[8]  R. Bruch.  Management of lake sturgeon on the Winnebago System ‐ long term impacts of harvest and regulations on population structure , 1999 .

[9]  Michael V. Thomas,et al.  Capture of Lake Sturgeon with Setlines in the St. Clair River, Michigan , 1999 .

[10]  M. Power,et al.  Latitudinal Variation in Lake Sturgeon Size as Related to the Thermal Opportunity for Growth , 1997 .

[11]  S. Guénette,et al.  Determinants of growth and body condition of lake sturgeon (Acipenser fulvescens) , 1996 .

[12]  D. Noakes,et al.  Growth strategy of juvenile lake sturgeon (Acipenser fulvescens) in a northern river , 1996 .

[13]  D. Noakes,et al.  Validation of Age Estimation for the Lake Sturgeon , 1995 .

[14]  A. Salam,et al.  Body composition of northern pike (Esox lucius L.) in relation to body size and condition factor , 1994 .

[15]  George Roussow.  Some Considerations Concerning Sturgeon Spawning Periodicity , 1957 .

[16]  E. Cren,et al.  THE LENGTH-WEIGHT RELATIONSHIP AND SEASONAL CYCLE IN GONAD WEIGHT AND CONDITION IN THE PERCH , 2022 .