ACUAMALLA®, the aquaculture netting for floating fish cages
Fish cages can be delineated into
floating fish cages, underwater fish cages, and submersible fish cages. The first ones consist of an enclosure made of netting which is completely or partially submerged in water, supported by a floating surface structure, known as a collar, and moored to the sea floor or shore. Submersible cages are floating cages equipped with devices which allow immersion to profound depths, but which are substantial enough to protect the structure and the fish from the impact of rolling waves. This makes them particularly well suited for installation in open water.
From a biological viewpoint
raising fish in cages represents an almost optimal situation for many species due to improved water quality which results in improved growth of the fish.
The majority of cage installations are floating fish cages, but submersible or semi-submersible structures are also used. These get used especially for raising fish far from the shore under specific climatic conditions. Submersible cages get used in open water that is prone to storms or extreme weather events (e.g. hurricanes, cyclones, or typhoons).
That way they are less exposed to the destructive action of the wind and waves.
Unlike floating fish cages, they are characterized by a wave-like motion. In marine environments these cages have the great advantage of being able to be submerged to a depth of 5 – 10 meters (16 – 33 feet) in the event of adverse meteorological conditions, thus protecting the structure of the cages and the fish in the cages from the impact of the waves.
Another advantage of of some types of submersible cages is found in the reduction of obstruction events caused by algae and other organisms.
The fact is that deposits of algae and other organisms form primarily in the upper layers of the water.
intended for high seas installation, have been developed in the last few years. Some of these resemble floating fish cages. The complex structures, which are suitable for use in open and deep water, also make it possible to install cages up and down the coast. Thus, problems of self-contamination and the spread of plagues and diseases are avoided. Often raising fish in cages in high seas is preferred because it leaves a low environmental footprint. It also is compatible with tourism along the coasts. In general, these cages are characteristically cylindrical or angular in shape, so as to offer less resistance to the waves.
Types of modern cages designed to meet different reproductive needs.
In general, the cages are made with plastic netting covering the top, bottom, and sides.
These panels are fastened to a support frame, which can be made from wood, metal, or plastic materials.
One of the main advantages of floating fish cages is their mobility, that is to say their ability to be easily moved to a new location if the need arises.
Qualities of the netting for floating fish tanks
ACUAMALLA®, the HORTOMALLAS® netting for raising fish in cages, has the following qualities:
- Strength under loads;
- Water resistant;
- Excellent resistance when exposed to atmospheric agents (oxygen, ultraviolet rays, etc.);
- Ease of repair;
- Absence of surface abrasions for the fish;
- Made of material that floats;
- Optimum abrasion resistance;
- Good elasticity.
HDPE (high-density polyethylene) netting often gets used as protection against predators. In fact, frequently fish cages are equipped with a double net with the one on the exterior, which has a larger mesh, being intended to protect the species being raised from attacks by predators. Exactly what netting gets used depends on the species to be raised, the way that they are to be raised, and the characteristics of the site where they will be raised.
In addition, cages made of flexible plastic netting are made with borders which come above the surface of the water to prevent jumping fish from being able to escape from the cage. The height of the border depends on the species being raised. Alternatively, a horizontal net can be used on the surface which also has the function of protecting the fish from predatory birds.
ACUAMALLA® makes for cages that withstand currents
Currents place dynamic loads on cages and the variables of the dynamic load are:
- Current velocity;
- The type of netting (mesh size, for instance);
- The orientation of the netting with respect to the direction of the current.
ACUAMALLA® does not get warped by currents and therefor does not suffer from a reduction in capacity.
Our polyethylene netting gets used especially in protected waters since it is resistant to the growth of incrustations.
In addition, they bear the load when placed under maximum stress by the concurrence of various stresses such as, for example, currents and waves.
Aquaculture netting is an invaluable component in any fish cage system.
Our netting for floating fish cages is safe and practical and is manufactured to obtain the highest quality product.
Because of its chemical and physical properties, high level of resilience, tear resistance, ultraviolet light resistance, density, melting point, alkali and chemical resistance, and lack of moisture absorption, it is considered to be the best on the market.
Resilience while in use, when being handled, and while being stored
Tradicionalmente se usaban redes anudadas
Traditionally knotted netting was used in the fishing industry. Knotted netting has good resistance to wear and tear and is relatively easy to repair.
However, protruding knots can harm fish by causing skin abrasions, especially as the density of fish increases.
One needs to know how to evaluate the weight and breaking load of nets. To illustrate: knotted nets weigh more than those without knots and nets without knots can cost up to 50% less, are more abrasion resistant, are easier to handle, and are stronger.
Durability, cost, and maintenance
Ultraviolet radiation causes degradation of the polymer (depolymerization) and consequently a loss of strength over time. Our netting comes with a UV stabilizer which is added along with other appropriate supplemental additives during the manufacturing process.
The Practice of Modern Aquacultur
Global aquaculture production has steadily increased over the course of the last few decades. The growing demand for such products at the national and international level has fomented growth in aquaculture production systems. To facilitate this growth, materials have been developed for aquaculture structures such as netting for floating fish cages. In the last few decades, the aquaculture industry has also intensified its production per unit of area of space or volume. This is primarily due to compensating for, among other things, growing competition for land surface and water for other uses.
Modern HDPE (high density polyethylene) fish cages, be they floating or submersible, represent such developments. They have evolved significantly from basic structures until becoming sophisticated and carefully designed systems. Many designs and models are currently available. Of the different kinds of cages, HDPE fish cages are widely used thanks to the versatility of the material used, the relative simplicity in the output of the diverse operations, and the comparatively limited capital investment that is required.
Factors to take into account about the installation of fish cages on fish farms
- Proper selection of the site with regards to exposure [to the elements].
- Environmental parameters which affect the well-being of the fish being raised and affect the farm. The proper placement of cages for a fish farm is of utmost importance for the general technical and economic success of the commercial operation and for reducing the environmental footprint of the farm.
- Size of the farm, be it an installation on land in ponds or in large natural bodies of water.
- Fabrication of structures that meet the needs of the operator and are appropriate for the surroundings where they are found.
- Maintenance and inspection methods.
- Safety procedures for the farm with an emphasis on reducing potential risk.