Aquaculture is the farming of fish, molluscs, crustaceans and algae in “more or less controlled” conditions. It constitutes one of the few industrial activities developed by the man who is integrated in the environment from the higher and most exquisite of respects helping, not in only few occasions, to its regeneration.
This “young” activity started to be developed in the environment which is better dominated by the man: the LAND. But with the pass of time, the logical tendency has been to place the crop installations in which it is constituted the natural environment of the produced species: the SEA.
In Norway, in the 1970s decades, it was started the installation of fish farms, in the quiet waters of the fiords. Later, the exceptional characteristics of the PE allowed that these floating garden centres could be placed in open sea and so different seas due to their waves, the tides and the winds like the North Sea or the Mediterranean Sea.
Every day, they are been built more and more in the sea of these marine farms, so it is avoided depopulation of the seas and making sure the supply and the quality of the product, following the rigid International and Community normative related to the protection of the Environment and to the products dedicated to the human consumption, which is more and more demanded.

The excellent properties and characteristics the PE pipes have turned it into the perfect element for the construction of floating structures which should stay into open sea during the whole year, supporting the hard and complex conditions.
The assembly process of the Circular Cages starts with the filling of the pipes with EXPANDED POLYSTYRENE. Then, the pipes are welded up to achieving the length defined by the perimeter of the structure.

Then, it is mounted the supports and the rail of PE of DN 90, 110 or 125 mm as well as the welding of a grid (NOT IN ALL THE CASES, THIS IS COMMOMN IN THE SHELTERED AREAS, BUT NOT WHEN WE TALK ABOUT OPEN SEA) mounted between supports and on the DN 90 mm PE pipe.
In the following photographs they can be seen:

a) Beginning of the dragging and launching of a finished Circular Cage.
b) Towing to the proper place in open sea.
c) Final result: circular cages floating in open sea.