Cage Farming Systems
HDPE and steel pens, moorings, feed barges and net handling for lake and marine farms.
Overview
Cage farming uses floating or submersible net pens moored in lakes or the sea. Systems include the pens, mooring grids, nets, feed barges and net handling equipment.
Where it is used
- Sheltered marine sites
- Offshore exposed sites
- Reservoirs and large lakes
Typical applications
- Salmon, sea bass, sea bream, kingfish, yellowtail
- Tilapia in tropical reservoirs
- R&D and broodstock cages
Benefits
- Lower CAPEX per kg than RAS
- Uses natural water body
- Scalable and modular
Limitations
- Exposed to weather and disease
- Environmental permits complex
- Escape and interaction risk
Typical project sizes: From 100 t/y freshwater cage farms to 20,000 t/y salmon sites.
HDPE Circle vs Steel Square vs Submersible
| Parameter | HDPE circular | Steel square | Submersible offshore |
|---|---|---|---|
| Best environment | Sheltered marine | Sheltered lake / marine | Exposed / offshore |
| CAPEX / m³ | Low–Medium | Medium | High |
| Wave tolerance | Medium | Low | High |
| Operations access | Boat | Walkway | Vessel + ROV |
| Best for | Salmon, sea bass, sea bream | Tilapia in reservoirs | Offshore aquaculture |
Buying guide
How to evaluate suppliers
- Design must be site-verified (Hs, current, wind)
- Anchoring calculated for 50-year storm
- Nets rated for predator load
Common purchasing mistakes
- Using coastal designs at exposed sites
- Under-specifying mooring
- Ignoring net cleaning strategy
Technical questions to ask
- What environmental design is used (Hs, T, current)?
- What is the guaranteed structural life?
- What net cleaning and change strategy is included?
Warranty considerations
- 24 months HDPE, 5–10 years mooring components
Maintenance
- Daily net check
- Weekly mooring inspection
- Annual full audit
Expansion capability
- Design grid for +30% cages
Energy efficiency
- Low on cage; feed barge and net cleaner dominate
Lifecycle
- 20–25 years HDPE, 15–20 years steel
Technical specification checklist
Line-by-line items you should include in a vendor-neutral technical specification. Download as CSV to hand to your engineer or drop straight into the RFQ Builder.
Budget guide
| Project size | Indicative CAPEX | Indicative OPEX |
|---|---|---|
| Freshwater cage (100–500 t/y) | USD 300k–1.5M | USD 1.5–2.5/kg |
| Sheltered marine (1,000–3,000 t/y) | USD 3–10M | USD 2.0–3.5/kg |
| Offshore submersible (5,000+ t/y) | USD 15–60M | USD 2.5–4.5/kg |
Indicative ranges only. Real budgets depend on site, regulations, redundancy and scope. Use for internal planning — always validate with an engineering study.
Major cost drivers
- Site exposure
- Cage size
- Barge scope
- Mooring complexity
Optional equipment
- ROV / camera system
- Predator net
- Automated feed barge
Installation notes
- Marine installation vessels required
Operating cost notes
- Feed 45–60%, health 10–20%, labour 8–15%
Maintenance reserve
- 3–6% CAPEX/year
Procurement checklist
- 1Complete metocean study
- 2Confirm site permits
- 3Confirm species & density plan
- 4Draft specification with structural KPIs
- 5Independent structural review
Supplier evaluation matrix
Score each supplier from 0 to 10 on each factor. Weights are pre-set with defensible defaults — override if your context differs.
| Factor | Weight | |||
|---|---|---|---|---|
Site-verified engineering | 25 | |||
Mooring & structural design | 20 | |||
Escape prevention | 15 | |||
Warranty & lifecycle | 15 | |||
Local install capacity | 15 | |||
Lead time | 10 | |||
| Weighted total | 100 | 0.0 | 0.0 | 0.0 |
Decision wizard
Frequently asked questions
Planning a project?
Now that you have the technical picture, get confidential quotations from project-matched international suppliers — or line up equipment financing first.
Continue exploring
RAS – Recirculating Aquaculture Systems
Land-based recirculating systems for salmon, trout, shrimp and other high-value species.
Aeration & Oxygenation Systems
Diffused, surface and pure-oxygen systems for ponds, tanks and RAS.
Filtration Systems
Mechanical and biological filtration for hatcheries, nurseries and grow-out.
Water Treatment & Disinfection
Intake, process and effluent treatment: UV, ozone, denitrification, degassers.