Aquaculture Technology
FISHFARMING EQUIPMENT

Netcage Systems

Index:deutsch


Waveproof Cages

SUBMERSIBLE NETCAGES for offshore farming

Submersible Offshore CagesThis "Vineta" cages are developed for industrial farming of various fish species (i.e.: Seabass, Seabream, Grouper, Salmon, Sturgeon etc.) all the year round at exposed open water areas such as seas and oceans. To prevent demage from storm impact and to provide optimum conditions for fish farming, the cage can be submerged. Completed with a painted or galvanized framework with a net chamber enclosed and a feed bunker on it allowing automatic feed supply and farming process supervision. To place the cage vertically, it is equipped with a special system providing its surfacing, submerging and positioning at a depth of 4-40 meter. Horizontal positioning of the cage is provided by the system of anchorage including anchor ties and anchors. Lightness and tracery of the cage are in full accordance with the sea landscape. The cage structure is produced to the "Rules for Building and Classing Underwater Vehicles, Systems, and Hyperbaric Facilities" and passes control assembling and testing at the manufacturing plant. It will have the certificate of the official "Maritime Register of Shipping". The steelwork is marked and packed as packages or in boxes wich can be transported in a standard 40-feet container.

The basic material of the (polygon) framework consists of rod welded tubular low-carbon (grade A) steel elements, connected with each other by flange-bolts. The threedimensional framework forming a regular nonahedron in plan, with three slanting trusses, running from the vertival columns to the geometric centre, closing at the feeder casing. The upper contour is completed with service platforms, passage walkways (500 mm wide) with railings (1.000 mm high) and removable hand-ropes, also to the feed bunker. The walkways and brackets are made of pipes with 120 mm in diameter. The vertical columns (720 mm in diameter, 2.250 mm long) house permanently buoyancy compartments, balancing tanks, and compensation tanks of residual buoyancy resulting from discharge of changing loads. Also sensors that measure depth of submergence, water temperature and underwater acoustic are housed there. The 5.980 mm long horizontal members of the bottom contour are made of pipes with 478 mm in diameter and house the main ballast tanks and compressed air cylinders, 6 of wich are ballast compartments and 3 are compressed air cylinders. Three mooring walls with wooden guard rails are provided for service boat mooring. To provide for safety of work of the attending personnel, the cage is equipped with removable single-row life-lines.
LayoutThe shape of the whole structure and all seperate sections are adjusted so that the cage experiences minimum rolls and trims at waves and current.
The experience of the underwater system operation has proved that the operation in the water column is the most effective structural measure to porotects structures from corrosion. Hot galvanized coating provides the structure service life of more than 20 years. This coating is reliable, practically excluding restoration and repair.
The system of automatic underwater feed distribution is intended for storage and measured distribution of feed for an autonomous operation of 7-30 days and located at the geometric center of the cage. The system consists of a water tight bunker of 3.000 liter (2 tons feed in average) of cylinder-conical shape (1.412 mm in diameter and 2.890 mm in height) and an automatically feed distributor (with a microprocessor) with a volumetric type dosage of 5 liter each. Compressed air is supplied to the pneumatic device by pipelines from compressed air cylinders, wich are replenished from a service boat, equipped with a compressor. To prevent water penetration into the feeder, its upper part is equipped with a water tight hatch with a rack-and-pinion lock. Inside the feeder the upper part houses selenoid valves, system controller and (24 Volt, 125 Ah) batteries. The system is made of corrosion-proof steel (6-8 mm thickness) and non-ferrous metals.
To submerge and surface the cage it is equipped with ballast compartments. The main ballast tanks are filled by gravity via drain holes equipped with ventilating valves with a remote control pneumatic drive. The balancing tanks are filled via kingston valve. The water from ballast compartments is replaced by compressed air (5-10 kg/cm3), supplied from the service boat compressor (min. 150 l/min). Air to the actuators is supplied through the pipelines made of corrosion-proof steel and rubberized hoses. The process of submerging and surfacing is supervised by the depth sensor, its display being located at the service boat or via water acoustic communication channel from the shore.
The signal buoy consists of cylinders of variable sections, providing a platform for deployment and protection of the control and monitoring complex of the cage. The size and weight characteristics are adjusted to provide survivability in the regime of extreme weather conditions. It can operate afloat at wave (force 8-9) and respective wind speed. It also can freeze in ice (up to 50 cm) to stay for winter. Flexible pipelines and electric cables coming from the signal buoy to the cage and supplying compresses air and providing power supply. Additionaly the buoy includes the antenna for an underwater acoustic control and monitoring system with an operation range of 10 km. Safety is provided by flashing beacons and corner reflectors, also from the feed bunker.
To install the cage at the water area (in a depth of up to 50 m), it is equipped with a special system of anchorage, consisting of anchor ties (i.e. a chain with a variable running mass) and 3 anchors (weighing 3-10 t), providing reliable functioning of the system under weather conditions given. The anchors are not included in the delivery, but are made on site (by the customer according to the drawings given). The anchorage system is designed for each particular site depending on hydro-meteorological conditions and depth of an installation site.
The net chamber with a volume of 1.000 to 2.000 m3 is preferably built from kapron or nylon net but could be changed to our polymere covered polyester net (mesh size 12, 20, 25 or 40 mm) too. The net chamber is placed within the steel structure at special guy-ropes, running up and down from the platform. The guy ropes are fastened to the feed bunker and the net chamber. To provide for harvesting of fish, the net chamber is equipped with a device, consisting of a rope system and portable hand operated winch, raising the bottom edge to the surface. To remove wastes from the net chamber it is equipped with a special tray device wich is lifted to the surface by the help of winches.
It is possible to position the cage system in a depth range in the water column of 4-40 meter. Afloated the system withstands waves (with personel to force 3) without personnel to force 6 and waves up to 6 meter. Submerged it is resistant to force 9 and respective wind speeds and waves up to 8-9 meter.
The axial diameter is 20,12 meter and the light displacement is 16,2 tons. Total height (including 2.000 m3 net chamber) is 12,1 meter, the minimum draught (at launching) is 0,8 meter and the maximum draught (including 2.000 m3 net chamber) is 8,6 meter.

 

CIRCULAR NETCAGES for all conditions

Circular NetcagesWe supply a wide range of single, double and triple ring cage collars, using black high density polyethylene (HD-PE 80-100) pipes in sizes from 200 to 450 mm , optional mounted with either dip galvanized steel or injection moulded plastic brackets (mounted usually every 2-3 m). All build with heavy gauge handrail and upright pipe (110-160 mm ) to resist deformation. The tailormade circular cages with a diameter from 10-60 m (32-189 m circumference) can be prepared for all types of weather and sea conditions from seabay to offshore sites. A safety chain inside the outer pipe ring and dividing plates welded inside the inner pipe ring, are available for safety reasons. A full circumference walkway decking is available optionally. A bird net stand, a dead fish collector and a sinker tube ring are available as accessoire. The cage pipes are shipped in parts and are welded on site.

Traditional rectangular cage systems of any size, we produce based on our ponton system

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Illuminated Cages

Illuminated submerged netcagesILLUMINATED NETCAGES for the fingerling production with natural zooplankton

20 years' experience in the field of global plankton research and fingerling production with natural plankton and years of tests under different environmental conditions in marine and fresh water, are the basis of the new "UWG- Solar cage system". The production method is based on plankton feeding in the natural environment like: lagoons, bays, fjords, lakes and large ponds, by means of attracting the organisms using a lamp located in the center of fine meshed submerged nets. Mainly Copepods and Cladoceres - but also a variety of other zooplankton organisms are photo sensitive and steadily swarm into the cages towards the light source.
The 2x2x2 m net cages (8 m3) are manufactured from highly resistant mono-filament polyester fabric (with mesh sizes 0,3 to 2,0 mm), is fitted with a zipper for easy access and a conduit for the electric cable. The net cage is stretched onto a strong stainless steel or aluminum frame. An efficient Solar-Generator is supplied for remote site operation. An electrical transformer can be supplied in order to reduce voltage to safer levels for use with water. Depending on the zooplankton populations, the fish-stocking density (from the fry stage to fingerling size of 5 cm length) can come to 5.000 Ind./m3 and survival rates of more than 90 % have been achieved with various marine and freshwater fish species.
The operation and maintenance is limited to the functional control of the system, a periodic cleaning with a portable high pressure cleaner, in order to prevent clogging effects, caused by detritus, algae and faeces, and the observations of the plankton development in the location.  The system is environmentally safe since no feeds or fertilizer are applied, the construction materials are inert, and the plankton consumption is minimal and does not affect the natural stocks.

 

Underwater lightUNDERWATER LIGHTS to increase growth and delay maturity

Underwater lights are used sucessfully (24 h/day) to delay maturation and increase growth in several fish species (like: Salmon, Trout and Cod etc.). in both sea- and landbased farms. This special submersible waterproof (IP 68) lights are made according to IEC and CE standards and are DEMKO and NEMKO approved. The socket of the special lamps is base E40 and the glass lens has a thickness of 5 mm. They have been tested at independant laboratories and light distribution files are used for calculating distribution in cages and tanks. The light intensity is 70-90 lm/W, the light current is 80-90000 lm and the colour temperature 4000-5000 K. They have dimensions (Length x Diameter) of 565 x 130 mm, a weight of 12,5 kg and are delivered with 20-40 m fixed marine cable (3 x 2,5 mm), and are available in two power ratings (400 or 1000 W, 3,2 or 5,5 A) for a voltage of 230 V/50 Hz.

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Net Material

POLYMER COATED POLYESTER NETS for cages

This special polymere coated polyester net is very strong and stable, but also flexible. The nets are 100 % stronger than conventional nylon nets, are highly UV-resistant, suitable for seawater and need no antifouling. They need less maintainance and have fewer escapes than nylon nets. Nets having been in use for more than 20 years still look like new and save a lot of total operation costs! The material is available on coils with a width of 3,6-3,8 m with a mesh size of 5 and 12 mm, and 5,0 m wide with a mesh size of 20 and 40 mm. With a weight of 450-550 g/m2 the cages need no lead sinkers. We deliver finished cages or also the material on coils.

Nets with the following specifications* are available as standard:

Typ

45/45-40

50/50-20

40/40-10

40/40-5

Square mesh size (open area)

40 mm

20 mm

12 mm

5 mm

Weight/m2

490 g

550 g

500 g

450 g

Tensile strength (ISO 53857) Warp/Weft

45 kN/m

50 kN/m

40 kN/m

40 kN/m

Expansion force (ISO 10319)

20 % 12 % 15 % 15 %

*Specification data on average (+/- 10 %).

Polyester Nets (PVC-covered) MS 5-40 mm

 

NYLON NET MATERIAL for cages and fishery

Nylon Nets (knotted or knottless) MS 4-30 mmThe production is based on a complete process, from the raw material, passing the different manufacturing phases like: matching, weaving, cutting and packing. Our aim is to assure a quality product to the customer. Woven in high resistant nylon, all our nets are machine sewen with double rows of stitching. UV-antifouling protection or colouration, on request. The finished nets are delivered in any shape or size with a mesh size of 4, 6, 8, 10, 12, 15, 18, 20, 25 or 30 mm, or only the net material itself.

Seine Nets in two designs:
Seine net with bag - consiting of two wings and respective bag in between, for the catch of fishes in lakes, rivers and ponds etc.
Seine net without bag - consisting of a well vault single wall, for the harvest of fishes in ponds, raceways and tanks etc.
Both nets are complete ready to use mounted in strong ropes, with foam floats and lead sinkers.

Gill nets in two versions:
Single os tripple sheet gillnets with a mesh size of 6-150 mm, in various heights and lengths.
Both gillnets are available loose or mounted ready to use with lead and float line.

Trap Nets in two outfits:
Fish traps - with one trouth and three galvanized iron rings, as well as two wing nets each 1,5 m long.
Fish bags - with two trouths and five iron or plastic rings, as well as two wing nets each 2,0 m long or a 3 m long guide net.
Both nets are complete ready to use. Longer wing or guide nets with floats and sinkers are possible.

Cast Nets in two arts:
Traditional Art - the lower line with harvest bags, which catch the fish.
Yugoslavian Art - the lower border will be formed to bags by ropes during lifting.
Both nets are complete ready to use and have a circumference of about 7 m, a height of approx. 1,7 m and a mesh size of 11 mm as standard.

Scoop Nets in two forms:
D- or O-formed strong, corrosion free scoope frames (wide 40-70 cm) with protection and preparation for handle.
Both nets are complete ready to use mounted with net bag (mesh size 4-20 mm), and a handle (length 1,3 m) from hard-wood as accessoire.

We deliver also other nets in various sizes.

 

PRECISION CLOTHS for aquaculture and hydrobiology

Precision woven screening fabric is a highly specialized monofilament fabric, characterized by precisely defined and controlled, consistent and repeatable material properties s.a.: mesh size, thickness, tenisle strenght, dimensional stability, cleanliness etc.). This fabric program includes precision sieves of different material strengths and offers a narrow mesh grading between 20-2000 micrometer and therefore fulfils all requirements of today's aquaculture and hydrological needs. Appropriate sieve fabrics are offered per running meter and as standard or customised products, such as filter-, dip-, hatching-, cage- and plancton-nets.
In Austria a catch of zooplancton for the production of fry and fingerlings is commonly practisized since more than 50 years. During the last years several important optimisations are archived allowing a better net construction and easy catching. With appropriate designed plancton nets, harvests of several tons per day can be achived. Thank's to this Austrian development of special sieve-net-systems, it is possible to grad the plancton in 3 different size classes during the catch. The result is the correct plancton size for all development stages from fish larvae to fry and fingerling. An expensive and complicated indoor-production of prey organisms (such as: Algae, Rotatoria, Artemia, Daphnia etc.) can be replaced.

Plankton nets in use Copepodes under 500 micrometer cloth

 

SHADING SHEETS AND PROTECTION NETS made of polyethylene

Shades and nets are made from UV-stable polyethylene material with a shadding density of 30-85 % to protect fish and ponds from light and birds. The sheets which let water (from rain) to drain off, are available on coils from 1,5 and 3,0 m width and can be manufactured with extra strong hem and eyes. For pricing allways the width of the coil is calculated.

Shadding sheeds and protection nets (shadding value approx.: 85, 75, 65, 50, 45, 30 %)

We also deliver bird protection nets with a mesh size of 15 - 150 mm.

 

TRAPS made from plastic

This easy to handle and maintenance free plastic traps have been tested in practice and are suitable for both professional and sport fisherman. Features such as a new shape and correct colouring are the result of fishing expertises. A favorable price/performance rate ensures highest economy in use. Of course the traps are saltwater and corrosion resistant and also resistant to crabs and other pests. This traps (with exchangable components) have a wide inlet opening and an integrated bait basket in the closed end cap. The traps are specially suitable for catching eels, but can also be used for other fish species as well as crayfish. This traps are delivered complete with sinker weight for submerging, which guarantee that the trap is allways positioned with the upper closed side on top, which in turn created a protection shelter for the animals.

Eel-trap 2-throatsCrayfish-trap 2-throats

The following versions are available:

Version Throats Length Weight
Eel-trap 2 1.4 m 4.2 kg
Eel-trap 1 1.0 m 2.4 kg
Crayfish-trap 1 0.6 m 1.0 kg

 

Dual head netwasher in useNET CLEANING SYSTEM with high pressure

This netcleaners maintain a flow of oxygenated water through the nets, that keeps them clean with minimal disturbance and no need to remove the fish from the pens. It's construction and design make the washers head working toward the net against its own high pressure water stream and can be used on all types of nets and cages. The netwasher loosen and pulverize, with its high pressure waterstream, algae growth, food remains and other fouling, which in turn will drift away by the current. The single head disk is easily used, the dual head disk is for faster cleaning. The fuel driven pressure pump with high output drives the head of the netwasher disk or can be used for pressure washing. It can be operated by one man from the boat or walkway/collar or underwater by a diver. Alternatively a hydraulic power pack for workboats is available, which is permanently installed with all the advantages of hydraulic drive, useful for pressure washing on boat and cages.

We also deliver all other nets and traps for commercial fishery!

Quality is our motto ... and your profit!

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