The
Flexi-Panel was developed by Ivor and Angus Johnson and others
at their salmon farm in the Shetland Islands. They were faced
with a problem, of how to quickly and efficiently select the larger
salmon for harvesting, without damaging or stressing any of the
fish. Whilst there were various methods and mechanical devices
that could be used to size grade live fish, all of them had major
disadvantages.
The
Johnsons, salmon farmers since 1983, had previously been size
grading their fish using rigid aluminium grids mounted into a
sweep net. The principle being to pull the sweep net through the
cage of fish, thus containing all the salmon in the sweep net.
The smaller fish simply swim through the gaps between the bars
of the metal grid and return to the main cage. The larger fish,
being unable to pass between the bars are retained in the sweep
net for harvesting. The main disadvantage of this system was that
due to the weight and rigid nature of these grids, the areas that
could be handled were insufficient to allow the fish to grade
through quickly enough. Also the rigid metal construction tended
to cause physical damage to some of the fish.
Having established the need to improve the grading methods, work
began on the idea of producing a system that offered flexibility,
large surface areas and was much lighter weight. Various ideas,
methods and materials were considered, resulting in prototypes
being tested to determine strength, size, durability, ease of
handling etc. In addition underwater filming was carried out to
observe the physical effects on the fish and the rate of transfer
through the panel during the grading process. The final product
to emerge from these tests was the patented 'Flexi-Panel', with
it's all round benefits of lightweight, strong and flexible construction,
which is very gentle on the fish and easy for the operators to
handle.
