Which parameters are critical for sturgeon farming in ras?
The critical parameters are temperature, dissolved oxygen, pH, ammonia, nitrite, nitrate, stocking density, feeding rate, hydraulics and redundancy of key equipment.
Technology - RAS for sturgeon
Technology for growing sturgeon in RAS systems
RAS allows you to raise sturgeon all year round - for meat or caviar - with complete control of temperature, oxygen and hydrochemistry. We analyze the environmental parameters, design features, growth, feed and breeding scheme for caviar.
Commercial sturgeon in the RAS basin
Short answer
Sturgeon farming in RAS explains how to organize fish production with controlled water quality, oxygen, temperature, stocking density, feeding and routine operations. Sturgeon technology requires accurate bottom area, oxygen, solids removal, biofiltration and redundancy calculations because the cycle is long.
What is a sturgeon RAS farm?
A RAS sturgeon farm is a farm with repeated use of water, where the quality of the environment is maintained by a cleaning and preparation system: mechanical cleaning, biofiltration, oxygenation, and, if necessary, ozone and pH correction. This makes it possible to grow sturgeon all year round by controlling temperature, oxygen and hydrochemistry.
History and types
Artificial breeding of sturgeon dates back to 1869 year, when on the Volga near Simbirsk F. V. Ovsyannikov was the first to carry out artificial fertilization of sterlet eggs. In the late 1970s, Soviet biotechnology for commercial sturgeon farming came to the United States and Western Europe; Today the direction is also developing in China and other countries.
Types for commercial RAS
- Siberian sturgeon (Lena population)
- Russian sturgeon
- Bester
- Sterlet
- Russian-Lena hybrid (Ro×Lo)
- Beluga (less often - long maturation period for caviar)
Growing conditions are similar; differences are in growth rates, marketable weight and ripening periods.
Farm options
Ponds
Simple infrastructure, but strong seasonality and dependence on climate and water quality.
cages
Growing in ponds; depends on temperature, oxygen and water use rules.
Forward flow
On a constant influx; simpler, but critically tied to the flow rate and quality of the source.
RAS
Maximum controllability and year-round use; higher demands on engineering and discipline.
Basic Environment Settings
| Parameter | Norm/optimum | Comment |
|---|---|---|
| T (incubation) | Russian sturgeon 12–16, beluga 12–14, stellate sturgeon 19–21, sterlet 12–14 °C | Fluctuation ≤2 °C/day, ≤0.2–0.3 °C/hour The mode is stable. |
| T (height) | 22–24 °C | Above 24–26 °C - decreased nutrition and growth. |
| O₂ | incubation/larval efflux ≥7.5–8; adults ≥7 mg/l | Critical threshold 5 mg/l. |
| NH₃ | MAC 0.05 (fish), 0.025 mg/l (larva) | Toxicity increases with pH and temperature. |
| NO₂⁻ | product 0.4 mg/l | Briefly up to 1 mg/l. |
| NO₃⁻ | 20–30 (juveniles) … 150–200 mg/l (product) | — |
| CO₂ | ≤10 mg/l | Up to 50 mg/L is tolerated when growth and FCR are impaired. |
| pH | 7–8 (in RAS ~7) | Critical <6 and >9. |
| Suspension (TSS) | up to 25 mg/l (product up to 30) | — |
| Iron | Fe²⁺≤0,1; Fe³⁺≤0,9 mg/l | Plaque on the gills, risk of death of fry. |
| H₂S | not allow | Lethal ~1 mg/l. |
| Salinity | fresh / up to 20‰ | — |
Design Features
- Sturgeon - bottom fish: water depth larva 30–40 cm, juveniles 70–80 cm, product and RMS ~100 see
- Maximum diameter of pools 7–8 m: with more, self-cleaning deteriorates.
- Water exchange: 1 revolution/hour for every 40–45 kg/m³ of fish.
- Drum filter: 40 µm (small fish) and 60 µm (product/RMS).
- Biofilter (22–24 °C): 0,5 g TAN for 1 m² of protected loading area per day.
- Light feces: Traps and hydrocyclones are often ineffective - static loading (mech-bio filter) is recommended for transparency.
- Densities: product 60–70 kg/m³; RMS 40–50 kg/m³.
- Degassing often not necessary if the biofilter is well aerated.
Growth of sturgeon in RAS
Estimated: ~14 months to 2 kg (Russian/Siberian/Bester) and ~16 months up to 1.5 kg (sterlet). The curve below is an example from a production table.
| Stage | Russian / Siberian / Bester | Sterlet |
|---|---|---|
| Caviar (“eye”) → 3 g | 40–55 days | 50–70 days |
| 3 → 60 g | 55–65 days | 75–85 days |
| 60 → 500 g | 150–180 days | 200–230 days |
| 500 g → product | 180–210 days (up to 2–2.3 kg) | 120–150 days (up to 1.5 kg) |
Stages of the commercial cycle
Incubation and maintenance of prelarvae. Incubators "Sturgeon", Weiss, McDonald. Incubation 6–9 days; O₂ ≥7.5 mg/l (outflow), control T every 2 hours. Aging: Russian sturgeon 8–10 days, beluga 12–16, sterlet 5–6.
Larva. Trays, pools ICA. 2–3 weeks up to 500 mg. T: Russian sturgeon 17–20 °C, beluga/sterlet 12–14, by the end of growing it is brought to 20–24.
Juvenile and commercial fish. Round (or square with rounded corners) and rectangular pools. T 18–26 °C, in RAS it is usually 22–24.
Specific oxygen consumption (SOC)
| Weight, g | URC, mg/(kg h) |
|---|---|
| 1–3 | 550 |
| 3–30 | 470 |
| 30–100 | 430 |
| 100–500 | 380 |
| 500–1000 | 350 |
| 1000–1500 | 320 |
| 1500–2000 | 300 |
| 2000–3000 | 280 |
| 3000+ | 260 |
Daily feed intake
| Hitch | % by weight |
|---|---|
| up to 5 g | 8–12% |
| 5–50 g | 4–5% |
| 50–100 g | 3–3,5% |
| 200–800 g | 1,5–2% |
| 800 g–1.5 kg | 1,2–1,5% |
| 1,5–3 kg | 1–1,2% |
Growing for caviar
A separate direction with its own broodstock economics and a long cycle.
Strategies for obtaining caviar
- Bottomhole: more expensive, more broodstock required.
- Lifetime: smaller herd and lower cost, but part of the market is skeptical.
- Hybrid: several milkings (often 2), then slaughter - balancing costs and margins.
Broodstock guide
1 t of caviar/year ≈ 30 tons of herd (bottom hole) or ≈ 15 t (hybrid).
Manufacturer life cycle
Up to 700–800 g (~9–10 months): selection of leaders by growth (~50% of the herd).
Up to ~2.5 kg (~1.5 years): Ultrasound sex determination, males - for culling, females - for rearing.
Up to manufacturer's age (3–6 years): Ultrasound control of maturation, preparation for wintering.
Wintering 4–6 °C (~2 months, without feeding) with periodic ultrasound monitoring.
Spawning: temperature rise to ~20 °C, stimulation, milking of eggs.
Recovery 6–18 months and repeated cycles; after a few - slaughter (according to strategy).
| Stage | Key parameters | Stern |
|---|---|---|
| Juveniles | 10–30 kg/m³; D=2–3 m; T 20–24; O₂>8; NH₄<2; NO₂<0,4; NO₃<100 | protein 50–60% / fat 15% |
| Product | 50–70 kg/m³; D=3–8 m; T 20–24; O₂>7; NH₄<4; NO₂<1; NO₃<200 | protein 45–50% / fat 10–15% |
| RMS | 40–50 kg/m³; D=3–8 m; T 20–24; O₂>7; NH₄<2; NO₂<0,7; NO₃<150 | protein 50–52% / fat 10–15% |
| Wintering | 40–50 kg/m³; T 4–6; O₂>7; NH₄<2; NO₂<0,7; NO₃<150 | — |
| Getting caviar | 40–50 kg/m³; T 4→20; O₂>7; NH₄<2; NO₂<0,7; NO₃<150 | — |
Truss composition and equipment
Typical sturgeon RAS blocks. For eggs, RMS, wintering (chiller) and spawning (heating) are added.
- Incubation/larva (if “from the calf”)
- Raising juveniles
- Product area
- RAS core: mechanical cleaning, biofilter, pumps, oxygenation, automation
- For caviar: RMS + wintering (chiller) + spawning (heating)
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Fish tanks⊙
Drum filter▤
Biofilter (floating load)▦
Mech-bio filter (sinking)⊳
PumpsO₂
Oxygenation☀
Ozonation systempH
pH adjustment⊞
Monitoring + autofeedingResource costs
⚡
Electricity
Pumps, oxygen/aeration, automation; for caviar - chiller and heating in blocks.
💧
Water
Make-up + drum rinsing + maintenance drains.
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Stern
Main OPEX; norms according to tables, control over palatability and water.
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Planting material
Caviar or juveniles - depending on the type and direction.
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Staff
Fish farmer + RAS engineer/operator; for caviar - a specialist in ultrasound and working with producers.
Dimensions of fish tanks
| Stage | Optimal, m³ | Allowable, m³ |
|---|---|---|
| Larva up to 500 mg | up to 20 | up to 30 |
| Baby up to 3 g | 30–40 | up to 50 |
| Juveniles up to 60 g | up to 60 | up to 100 |
| Commercial fish | up to 150 | up to 200 |
~65%
Final survival rate (caviar → product)
~1,3
Final Feed Ratio (FCR)
~14 months
Up to 2 kg (Russian/Siberian/Bester)
60–70
kg/m³ - density on the product
Project implementation
Technology design — our profile (service “Design of fish farms”).
Building design.
Supply of equipment.
Construction of a building.
Installation of technology.
Launch and stocking.
Let's design a sturgeon farm - for meat or caviar
From environmental parameters and broodstock strategy to equipment selection and working documentation.
Completed projects
Sturgeon RAS farms that we sold: Azerbaijan (100 t), Georgia (50 t), Kazakhstan (20 t), Moscow region, Krasnodar region, as well as a farm on 1 tons of caviar/year in Moldova.
FAQ
Frequently asked questions
Clear answers to the questions that usually appear before a RAS fish farm project starts.
Can standard equipment be used without calculation?
It is risky. Equipment must match the species, biomass, feed load, water quality and building layout. A generic set can lead to weak filtration, unstable oxygen or difficult maintenance.
How is the technology selected for a project?
The choice depends on fish species, target capacity, water source, climate, available building, energy costs, staff skills, market format and the required level of automation.
How long does sturgeon take to reach 2 kg in RAS?
Russian and Siberian sturgeon and bester reach a market size of 2–2.3 kg in about 14 months from eggs: around 9–10 months to 500 g and another 6–7 months to market weight. In ponds this takes 3–4 seasons - in RAS the fish grows all year round at 20–22 °C.
How fast does sterlet grow in RAS?
Sterlet is smaller and grows more slowly than large sturgeon species: about 16 months from eggs to a market size of 1.5 kg. Its lower market weight is offset by steady demand for portion-size sterlet.
How long does sturgeon fry take to reach 500 g?
From eggs to 3 g - 40–55 days, to 60 g - about 2 more months, to 500 g - another 5–6 months. In total about 9–10 months; at 700–800 g the first grading and selection of fast-growing leaders is usually done.
What determines sturgeon farming profitability?
Sturgeon aquaculture profitability is driven by the product mix (meat only, or meat plus caviar), the price of feed (about half of operating costs), energy for pumps and heating, stocking density and capacity utilisation. Caviar formats have a longer cycle but a much higher revenue per kilogram; guideline profit and payback by format are given in the model range on the sturgeon farm page.
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