Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
SPECIFICATION
MESH SCREEN MAXIMIZING PRODUCTION IN MYTILIDAE CULTIVATION
FIELD OF THE INVENTION
The present utility model relates to the aquaculture industry. In particular,
this
utility model relates to a cultivation system that improves the environment
for Mytilidae
while they are in stages of growth and fattening, providing favorable
environmental
conditions for the growth and production yield per area of the used column of
water. By
means of a submersible float system, this technology minimizes the adverse
environmental conditions such as freshwater areas in estuaries, exposure to
the air due
to waves, wave energy and, through a system of minimum filtering sieve,
maximizes the
use of the water column. These conditions allow the increase in productivity
of cultivation
compared to a traditional system of cultivation by hanging, where ropes are
left to hang
loose, subjected to water currents and severe weather, which generates low
production,
or even total loss of production when bad weather or storms occur.
The present utility model comprises a mesh screen for a cultivation system to
be
used both in protected areas and non-protected areas (intense waves) without
detachment of molluscs, thereby preventing production losses. The present
screen
configuration for the aquaculture cultivation system favors growth and
production yield
by area of water used. In addition, the present screen is incorporated into a
submersible,
controlled float system, which minimizes adverse environmental conditions when
used
in non-protected areas and by means of the screen system of minimum sieve the
use of
the water column is maximized. These conditions cause the cultivation
productivity to
increase, compared to the traditional system by hanging, and in particular,
increases the
yield of molluscs in exposed coastal areas, which are adverse for the molluscs
cultivation.
For example, the Chilean mussel industry, located mainly in Los Lagos Region,
has grown at an average annual rate of 30% in recent years. This has involved
a greater
demand for new coastal protected areas for the cultivation of about 2,400
hectares per
year. However, the problems identified for cultivation in these areas at both
national and
global levels are:
i) they present high densities of cultivation, overloading the ecosystems;
ii) there is limited availability of new protected coastal areas; and
iii) there is high competition for the use of these areas with other
activities, such
as salmon farming. For this reason, an opportunity for development of marine
aquaculture on a large scale is foreseen, increasingly oriented toward sites
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of open sea and exposed coastal areas, which require appropriate
technologies for the species to be cultivated.
STATE OF THE ART
Currently, there are several technologies relating to aquaculture or fish
farming.
Among them is the patent ES1043285 disclosing a technology for breeding or
cultivation
of mussels, specifically an improved nursery for growing mussels in open sea,
wherein
the nursery is formed from a rope or longline horizontally arranged, which is
located in
the mentioned position using floats located at the ends of the rope,
consequently leaving
the rope horizontally positioned, and fixed at a predetermined depth by means
of chains
pulled by one of its ends to the longline, whereas be the opposite end are
pulled by
mooring blocks or anchors located on the bottom of the sea, wherein the
nursery has the
following features: the rope or longline is made of polypropylene, and it is
submerged by
the action of floats positioned over the same, in adequate number to its
length, the rope
or longline remains submerged at high tide at about 4 meters from the surface,
and at
low tide at about 0.5 meters, wherein the rope or longline is connected with
the floats to
the bottom by mooring blocks or anchors or other similar elements, having an
adequate
weight to keep the ends anchored, and intermediate points of the longline
using chains
or similar elements, connected at one end to the rope and at the opposite end
to the
mooring blocks or anchors. From said rope hang a plurality of ropes located
vertically, in
which the seeds of mussels are placed for fattening inside the sea.
But the patent ES1043285 does not maximize the aquaculture production,
because it does not efficiently use the cultivation area, since the plurality
of ropes is
placed vertically, without preventing the tangling of the hangs, which implies
an inefficient
use of the cultivation area. As shown in Figure 3 corresponding to the prior
art, a plurality
of cultivation hangs (21) hang from a mother longline (24). The longline (24)
is supported
by a rod (26) and uses floatation means to keep the cultivation hangs (21)
from
contacting the bottom of the sea. But, as seen in figure 3, sea currents or
waves could
strike the hangs, making them hit with each other. This implies a loss of
production that
in some cases could reach 90%. In addition, and given the length of the
cultivation hangs
(21), these get easily tangled with each other, hampering the handling of
these cultivation
hangs (21) and resulting in production losses.
SOLUTION TO THE TECHNICAL PROBLEM
To remedy the technical problem, a change in the configuration of cultivation
sleeves is presented, for maximizing the aquaculture production through a mesh
screen
that minimizes the sieve, allowing for a configuration which minimizes the
area that
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cannot be used for the cultivation, or minimizes the sieve for water passage
and
maximizes the area for production of molluscs (Mytilidae), regardless of
whether the
mesh screen is located in protected areas or exposed areas for cultivation,
where the
exposed areas are adverse for the cultivation due to currents and/or high
waves.
SUMMARIZED DESCRIPTION OF THE INVENTION
According to a general aspect of the disclosure, there is provided a
cultivation
mesh screen of minimum sieve that maximizes the aquaculture production; the
cultivation
mesh screen comprises a plurality of cultivation hangs hangable by means of
holding
means to a mother longline submerged under the water level and joint to a
controlled
floatation means; attachment means, alternately jointing adjacent cultivation
hangs,
thereby forming the cultivation mesh screen with an area without sieve so as
to prevent
tangling of said plurality of cultivation hangs. The cultivation mesh screen
is kept
submerged under the water level by the weight of the cultivation mesh screen
allowing it
to remain perpendicular with respect to the horizontal.
According to another general aspect of the disclosure, there is provided a
cultivation mesh screen assembly comprising a cultivation mesh screen
according to the
present disclosure, a mother longline submerged under the water level and a
controlled
floatation means. The mother longline is joint to the controlled floatation
means, at least
one of said plurality of cultivation hangs hanging from the mother longline by
means of
the holding means, wherein the controlled floatation means further comprises
auxiliary
floatation means jointed by means of ropes.
Preferred embodiments of the invention are described hereunder.
The present invention corresponds to a cultivation mesh screen of minimum
sieve,
that maximizes the aquaculture production, where the cultivation mesh
comprises: a
plurality of cultivation hangs hanging from a mother longline, wherein each
cultivation
hang is joint by means of attachment means, alternately jointing a cultivation
hang with
the next cultivation hang, thereby forming the cultivation mesh.
The design of the submersible cultivation mesh has features allowing the
effect of
waves to decrease (which causes line breaks and losses in the traditional
systems), by
placing the main float line holding the units of cultivation to a depth that
may vary during
operation. The difference in the submersible cultivation mesh with the
traditional system
is that the location of the floatation line is adjustable in the water column
during the time
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of cultivation. The depth of the final design is defined according to the
results obtained
from measurement of the currents, the experience with the preliminary designs
and the
results of growth at different depths. This technological solution has the
appropriate
design for the cultivation of mussels in exposed coastal areas. Currently,
this knowledge
does not exist.
The technology of the cultivation system by traditional hangs, known as
submersible longline, can be applied to molluscs cultivation (Mytilidae,
Ostreidae and,
Pectinidae) and macroalgae. These species require being suspended in the water
column during their stages of growth. The screen is can be applied to
Mytilidae.
The most relevant application is that, with this technology, it is possible to
install
cultivation centers in exposed coastal areas. In the case of Chile, there
exposed coastal
areas are not used due to the lack of technology for these purposes.
DESCRIPTION OF THE FIGURES
Figure 1A shows a preferred embodiment of the cultivation mesh screen (20)
formed by a single sleeve or cultivation hang (21).
Figure 1B shows another preferred embodiment of the cultivation mesh screen
(20) formed by a plurality of sleeves or cultivation hangs (21).
Figure 2 shows a preferred embodiment of the cultivation mesh screen (20)
formed by the sleeves or cultivation hangs (21) and auxiliary floatation means
(2).
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Figure 3 shows the traditional cultivation system by hangs of the prior art.
DESCRIPTION OF THE INVENTION
As shown in Figures 1A and 1B, the present invention discloses a cultivation
mesh screen (20) of minimum sieve that maximizes the aquaculture production
and
prevents tangling of the hangs, wherein the cultivation mesh comprises: at
least one
cultivation hang (21) hanging from a mother longline (24) by means of holding
means
(22) and the mother longline (24) is joint to a controlled floatation means
(4); attachment
means (23), alternately jointing each cultivation hang (21) with an adjacent
cultivation
hang (21), thereby forming the cultivation mesh (20) with an area without
sieve (25),
wherein the cultivation mesh (20) is kept submerged under the water level (30)
and the
weight of the cultivation mesh (20) allows it to remain perpendicular with
respect to the
horizontal or the sea bottom (31).
In a preferred embodiment, the distance between the cultivation hangs (21) is
about 20 cm to 70 cm, and in another preferred embodiment, the distance
between
cultivation hangs (21) is about 30 cm to 50 cm.
In another preferred embodiment, the area without sieve (25) is about 400 cm2
to
4900 cm2, and in another preferred embodiment, the open area without sieve
(25) is
about 900 cm2 to 2500 cm2, where the area without sieve (25) formed by the
cultivation
hangs (21) and the attachment means (23) has a rhomboid shape.
In a preferred embodiment, the diameter of the cultivation hangs (21) is
between
4 cm and 15 cm, and in a more preferred embodiment, between 5 cm and 10 cm.
The cultivation mesh (20) is kept in a determined position by weights (9),
thereby
holding the controlled floatation means (4) with tethers (7) to the bottom,
using a clamp
for the ropes or cables (6), and the location of the cultivation mesh (20) is
known by
means of marker buoys (3), held to the weights (9) with buoy cables (8),
thereby forming
a cultivation system (1), with the cultivation mesh (20) of the present
technology.
In another preferred embodiment, and when the weight of the production in the
cultivation mesh (20) exceeds the buoyancy of the means of controlled
floatation means
(4), this controlled floatation means (4) further includes some auxiliary
floatation means
(2) attached with ropes (5).
In addition, in another preferred embodiment, the cultivation mesh (20) is
held to
the sea bottom (31) by bottom tethers, not shown in the figures.
In another preferred embodiment, the cultivation mesh (20) is formed by a
single
cultivation hang (21) or is formed by a plurality of cultivation hangs (21).
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=
In addition, the cultivation mesh (20) is kept submerged in a controlled
manner
by means of the controlled floatation means (4) under the water level (30).
The process comprises three stages: (1) Collection of the seeds of Mytilidae
in
its natural environment, wherein collectors are positioned in the mother
longline for the
larvae of Mytilidae to adhere to the same, and subsequently to be removed for
the next
stage; (2) Putting the seeds on a stringbed in the growth hangs. The seeds are
separated
from the collector manually. Once the seeds have selected, they enter a
stringbed
equipment. Ropes and seeds enter a pipeline of 100 to 120 cm. The seeds are
put in a
cylindrical screen of 5 mm having a knot at the beginning for allowing the
accumulation
of seeds and the rope inside of the same. In this manner, hangs for fattening
are
manufactured, with a total length of 400 m. (3) Meshing of the hangs. It
consists of
making a screen with the already manufactured hangs of about 2.5 m wide and
about
5.6 m high. The total length of the hangs must be 80 m. These will be attached
at one
end to a rod of 3 m long and 80 mm in diameter, forming a sine of 8 m in
depth. The
hang is attached again to the rod, spaced 50 cm from the first attachment
point. The
process is repeated until completing the full length of the hangs. Then, the
meshing of
the screen starts manually, from one end of the hang, a first section of 50 cm
is measured
and a parallel separated section. These are joint together with a tie each 50
cm. This
process is repeated until the bottom part of the sine formed by the hang, and
further
repeated with the rest of the hangs. The spacing between adjacent ties in the
rod can
fluctuate between 30 to 50 cm, and the initial depth of the sine formed with
hangs can
fluctuate between 5 to 10 m.
EXAMPLE OF APPLICATION
The present technology and its components have been tested in an exposed
coastal area, with flow speed between 2 cm/s and 12 cm/s, unlike protected
coastal
areas with flow speed of between 0.2 cm/sec and 1.2 cm/s, having excellent
results for
cultivation in these exposed areas. For example, seeds of Mytilidae were
collected in its
natural environment on a system of between 40 and 80 buoys of 350 liters
jointed by a
rope, called mother longline, which longline was arranged in the sea in areas
known for
the occurrence of Mytilidae larvae. In the mother longline, pieces of fishing
nets made of
polyamide material, discarded, with dimensions of 10 cm wide and long about 4
m were
arranged. These pieces of nets are called collectors, to which the Mytilidae
larvae is fixed.
After noting that the collectors have Mytilidae attached in a concentrated
manner of
between about 10 and 20 mm, the collectors are removed from the water, for
putting the
seeds in a stringbed for growth: each collector is located in a working
platform, in which
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the seeds are shed from the collector. If standardization of the seed size is
desired, the
seeds are arranged in a sorting machine, which consists of a funnel where the
seeds
enter, then falling into a tube with screw conveyor, taking them to a first
section with slots
that select a desired size, being able to obtain up to three sizes of seeds.
In this manner,
it is possible to obtain seeds of different sizes. Then, the seeds are moved
to a stringbed
machine, consisting of a funnel through which the seeds enter with high-
pressure water
toward a transversal tube with a diameter of about 7 mm. A rope of 18 to 22 mm
goes
through the transversal tube. The end of the rope is pulled to move it
forward, moving
the seeds and the rope through the pipe of about 100 to 120 cm. At the end of
this
metallic tube, at its edge, it overlaps with a cylindrical cotton mesh with a
sieve of 5 mm,
allowing the seeds to be deposited in this mesh, having at its starting end a
knot, thereby
allowing the accumulation of seeds and rope inside the cotton sleeve, wherein
said rope
comprises filaments where the seeds are held. With this system, fattening
hangs are
manufactured, which will be placed in the cultivation system for its growth in
the sea.
These hangs have a total length of up to 400 m depending on the length of
desired the
rope to be included in the mother longline with seeds. Then the meshing of the
hangs of
the present utility model is performed, to maximize the area of the water
column, wherein
the cultivation mesh (20) is formed by the meshing of the cultivation hangs
(21), having
about 2.5 m wide and about 5.6 m high, with a total length of the hang of
about 80 m. In
a rod of 3 m in length and a diameter of 80 mm, one end of the hang it tied to
the rod,
forming a sine of 8 m in depth, tying again the hang in the rod, separated by
50 cm from
the initial tie. This process is repeated until completing the full length of
the hang. Then,
the meshing is performed, from one end of the hang with a spacing of 50 cm
between
hangs, and at the same time, these hangs are joined with the attachment means
(23)
every 50 cm, to form the cultivation mesh (20).
With the present cultivation technology, production increases in 1.9 times per
line
compared to the traditional cultivation system by hangs, known as longline
system. This
can decrease maintenance costs by 20%, avoiding tangling of the hangs and
enabling
to perform the entire process of fattening in four months. A graphical way to
see the
efficient use of the production area is to compare Figure 1A, 1B or 2 with
figure 3. By
observing these figures, it is possible to see that figures 1A, 1B and 2 have
double the
length for cultivation hangs (21) with respect to Figure 3 (prior art), with
the same aquatic
area for production. In addition, the present cultivation mesh (20) is useful
for cultivation
in both protected areas and non-protected areas.
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List of constituent elements:
Cultivation system (1)
Auxiliary floatation means (2)
Marker buoys (3)
Controlled floatation means (4)
Ropes (5)
Clamp for ropes or cables (6)
Bottom tethers (7)
Buoy cables (8)
Weights (9)
Cultivation mesh (20)
Cultivation hangs (21)
Holding means (22)
Attachment means (23)
Mother long line (24)
Area without sieve (25)
Rod (26)
Water level (30)
Bottom (31)
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