Growth Rate of Juvenile White Sturgeon
Growth rate of sturgeon can vary significantly, based on feeding conditions, water temperature and the abundancy of prey, especially in the earlier years.
All fish in this study were caught by captain Yves Bisson or through fishing clients. 32 juvenile White Sturgeon from the Lower Fraser River system that had been caught and released a minimum of 3 years apart were used. The 3-year period allowed for significant growth and minimized the data variability due to measurement inconsistencies. Only fish that were caught a minimum of 3 times in their juvenile life stage were used.
As per standard recording or fish, measurements for the study were done tip of the nose to fork, along the medial lines of the fish. Size of the recorded fish ranged from 23cm to 100cm in length, however only 5 of the 199 measurements were below 50cm. This is likely due to the fact that the bait used targeted larger fish.
Key Results
The average growth rate of the Fraser River Great White Sturgeon between 50 and 100cm was 5.2 cm per year ± 1.4cm/yr (3.8 to 6.6cm/yr). While the growth rates can be assumed to lessen over time (and therefore more logarithmic than linear), a linear model fit well for the juvenile sturgeon (a 0.977 correlation coefficient).
| Measured | Parameter |
| 5.2 | Avg growth rate (cm/yr) |
| 1.4 | Standard Deviation (cm/yr) |
| 8.3 | Max growth rate (cm/yr) |
| 3.1 | Min growth rate (cm/yr) |
| 5.0 | Median growth rate (cm/yr) |
| 32 | Number fish used in study |
| 199 | Number measurements |
The following chart shows the summarized growth rate of Juvenile White sturgeon as a function of age, with upper and lower one standard deviation (67% of the sturgeon should fall within this range).
As a quick measurement in the field, an average White Sturgeon grows 2 inches per year and reaches 100cm at age 15. This assumes an age of 5 at 50cm as per published literature by the Department of Fisheries & Oceans.
Growth Rate of Juvenile White Sturgeon – Comparison with published Data
Results from this study of juvenile White Sturgeon compare well with data from the Department of Fisheries & Oceans, who state that the average size of a White Sturgeon at 5 yrs old is approximately 50cm (ref 1) and continues to grow at approximately 5cm/yr for the next 20 years. (or up to 150 cm), then 3cm/yr from 150 to 170cm (Ref 2: Life Cycle of A White Sturgeon)
Growth rates from a common white sturgeon growth chart used in the industry shows a fairly aggressive growth rate in comparison to what was found in our study. This Growth table starts at 94 cm, with a 7.3cm/year growth rate, compared to a more modest 5.2cm/year in this present study. Using this chart, a juvenile sturgeon would be approximately 10 years old when reaching 100cm in length, vs 15 using the measurements from the current study.
From OregonFishingInfo.com, the Columbia White Sturgeon is said to grow between 7 & 12 inches during year 1, followed by 4 inches (10cm) per year up to 3ft, then 3 inches (7.5cm) per year until maturity. The Fraser River fish measured in this study showed a much lower growth rate.
In 1963, a comprehensive study of the Age and Growth of the White Sturgeon in the Fraser River was put together by Masters Candidate, Saul Nelson Semakula for the department of Zoology at UBC.
Mr Semakula studied mainly juvenile sturgeon, with the majority being caught in salmon nets in New Westminster, or by gill nets at the Dewdney Slough near Mission. Growth rates were determined by establishing a relationship between the growth of the first pectoral fin ray and the fork length of the fish, then back-calculated to calculate growth at particular years. It was found that the females grow much faster than males after the age of 16, however the number of samples above 100cm was very limited.
Conclusions
The average growth rate of the juvenile White Sturgeon in the Lower Fraser River & Tributaries was found to be 5.2 cm / year (from 50 to 100cm). Assuming 5 years to reach 50cm, a 100cm sturgeon would be approximately 15 years old.
Growth rates of juvenile match well with published data from the Department of Fisheries & Oceans and the study done by Mr Semakula, but are much more conservative than growth rates found in the generally used White Sturgeon Weight / Age chart plus the table published by oregonfishinginfo.com
White Sturgeon Growth Rates
