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Aquaculture draws on well-established
engineering fields for most of the design and
construction needs of its production facilities.
Building earth ponds is similar to building roads -
a knowledge of the characteristics of soils and the
limits of safe design are the basis of good
construction. Similarly, the buildings used for
hatcheries and other support activities are no
different from those common in the housing,
agricultural and commercial sectors.
Sometimes ponds are lined with plastics or other
impermeable materials, and here the techniques are
similar to those for civil structures such as
potable water reservoirs or sludge tanks. The
design and installation of water control gates,
including in unstable soils, benefits from the long
experience in this field in the agriculture and
irrigation sectors. An understanding of
hydrodynamics allows ponds and tanks to be built
with good water circulation, oxygen mixing and
without 'dead spots' where sediments might
accumulate and cause health problems to fish.
For installations in the sea, the situation is
somewhat different and many of the important
engineering solutions, such as for fish cages or
suspended shellfish growout systems, have had to be
developed by aquaculturists themselves. They have
benefited however from the accumulated knowledge of
seafarers in general and fishermen in particular,
in the design and operation of mooring and buoyage
systems. More recently, when fish farmers have
turned their attention to how to operate fish cages
in locations further offshore where seas are
rougher, the experience of the oil exploration
industry has proven very valuable.
Techniques have been developed in recent years
for the production of fish and other aquatic
products in closed recirculation systems. To make
these work, aquaculturists have needed to develop a
knowledge of the biological processes operating -
such as how bacteria can be used to neutralise and
re-cycle the nitrogenous waste products produced by
growing fish - and how to engineer the systems to
meet the biological requirements. Knowledge of
bio-engineering from the waste treatment and water
treatment industries has made contributions to the
development of closed aquaculture systems and there
is probably more that could be usefully transferred
from the sewage treatment sector to help solve
problems in fish rearing.
Modern materials have brought many benefits to
aquaculture. For instance, custom made plastic
joints have simplified the construction of sea
cages, and made them more reliable in high stress
conditions. Experiments with huge free-floating or
sunken net cages operated in the open ocean were
begun several decades ago, for instance in the
Caspian Sea. These showed some promise, but more
reliable construction materials will make the
farming of fish in such structures increasingly
feasible. Modern materials and production methods
have been important also, in the construction of
plastic filter substrates for indoor recirculating
systems. The fine detail of these has been found to
make substantial differences to the efficiency of
biological filters.
In shrimp farms, specially designed matting
materials that stand upright on pond bottoms, with
a structure that promotes the growth of the small
animals and plants that the shrimp can thrive on,
have recently been developed and shown to boost
production.
Engineering skills are important in the design
of most aquaculture facilities and good engineering
can affect the efficiency and economics of
production. If capital costs can be minimised while
still maximising productivity and reducing risk,
the farming operation will be more profitable.
Aquaculturists have proven very innovative over
the past fifty years, constantly developing new
technologies to support their farming operations.
As new production methods and species for farming
are developed, the engineering solutions needed to
support them will continue to evolve.
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