Lobster abstract
A lobster habitat includes one or more elements made of a sea water
resistant material that are provided with recesses in their opposite
largest surfaces which are intended to form hiding-places for lobster
fry.
Lobster claims
I claim:
1. An artificial habitat for lobsters comprising:
at least one solid block of water resistant material having two
opposite generally vertically ascending main surfaces and two opposite
side surfaces, each of said main surfaces being larger than each
of said side surfaces, said main surfaces being farther apart at
a bottom of the habitat that is adapted to rest on a seabed when
the habitat is operating than at a top of the habitat,
each of said main surfaces having plural lobster habitat openings
therein that extend generally horizontally into said at least one
solid block, said openings having plural sizes and depths to accommodate
lobsters of plural sizes.
2. The habitat of claim 1 further comprising a bottom section
adapted to rest on a seabed when the habitat is operating, said
bottom section comprising a parallelepiped slab of water resistant
material.
3. The habitat of claim 1 wherein said water resistant material
is concrete.
4. The habitat of claim 1 wherein the bottom of the habitat comprises
a water resistant material of a first density and the top of the
habitat comprises a water resistant material of a second density
less than said first density.
5. The habitat of claim 1 further comprising plural ones of said
at least one solid block connected at respective said side surfaces.
6. The habitat of claim 5 comprising three solid blocks connected
in a Y-shape.
7. The habitat of claim 5 further comprising a bottom plate connecting
said solid blocks at respective main surfaces adjacent one end of
the habitat.
8. The habitat of claim 1 further comprising a boat mooring connection
at one end of the habitat.
9. The habitat of claim 1 wherein ones of said openings on one
of said main surfaces are displaced in relation to others of said
openings on the other of said main surfaces.
10. An artificial habitat for lobsters comprising:
at least one concrete block having two opposite main surfaces and
two opposite side surfaces, each of said main surfaces being larger
than each of said side surfaces,
each of said main surfaces having plural lobster habitat openings
therein that extend into said at least one block, said openings
having plural sizes and depths to accommodate lobsters of plural
sizes,
wherein a first end of said at least one block adapted to rest
on a seabed when the habitat is operating comprises concrete of
a first density and an opposite end of said at least one block comprises
concrete of a second density less than said first density.
11. The habitat of claim 10 comprising three concrete blocks connected
at respective said side surfaces in a Y-shape.
12. The habitat of claim 11 wherein said first end of each of
said blocks comprises a parallelepiped slab of concrete having said
first density.
13. The habitat of claim 12 further comprising at least one bottom
plate for connecting said slabs of said three blocks to each other.
14. The habitat of claim 10 wherein each of said openings has a
longitudinal depth into said at least one block that is larger than
its maximum lateral extent, and wherein the maximum lateral extent
of ones of said openings at one end of said at least one block adapted
to rest on a seabed when the habitat is operating are larger than
the maximum lateral extent of ones of said openings at an opposite
end of said at least one block.
15. The habitat of claim 10 wherein plural ones of said openings
extend from one of said main surfaces to the other of said main
surfaces.
16. An artificial habitat for lobsters comprising:
at least one solid block of water resistant material having two
opposite main surfaces and two opposite side surfaces, each of said
main surfaces being larger than each of said side surfaces,
each of said main surfaces having plural lobster habitat openings
therein that extend into said at least one solid block, said openings
having plural sizes and depths to accommodate lobsters of plural
sizes, wherein ones of said openings on one of said main surfaces
are displaced in relation to others of said openings on the other
of said main surfaces.
17. The habitat of claim 16 wherein said openings are semicircular
at said main surfaces and have flat floors.
18. The habitat of claim 16 wherein each of said openings has
a longitudinal depth into said at least one block that is larger
than its maximum lateral extent.
19. The habitat of claim 18 wherein the depths of ones of said
openings at one end of said at least one block adapted to rest on
a seabed when the habitat is operating are deeper than the depths
of ones of said openings at an opposite end of said block.
20. The habitat of claim 16 wherein one end of said at least one
block adapted to rest on a seabed when the habitat is operating
comprises a water resistant material of a first density and another
end of said at least one block comprises a water resistant material
of a second density less than said first density.
Lobster description
The invention concerns a lobster house or lobster habitat in water
resistant materials consisting of one or more elements equipped
with recesses of varying sizes of opening and depth, which can be
through-going in the element, wherein the element is composed of
a block of uniform thickness or a block which is thicker at one
end.
In the field of marine biology it is known to deploy so-called
fish houses on the seabed. This is due to the fact that fish and
marine organisms have been observed to gather around shipwrecks
on the seabed, oil installations and the like. Such structures have
been shown to be well suited to attract stationary fish, i.e. fish
which remain in the same area for their entire lives provided that
the supply of food is adequate.
The present inventor has observed in Japan amongst other places
that sub-merged fishing boats, exposed pipe structures and car tyres
provide a good basis for marine growth and attract marine organisms,
but it appears to be important for these structures to be stable.
Submerged tyres which are moved by the current do not provide the
same amount of marine growth as, e.g., a stationary and stable wreck.
Lobsters are a stationary crustacean. However, they are cannibalistic
and dependent on natural hiding-places in order to attain full growth.
These hiding-places must provide adequate protection while at the
same time giving access to volumes of water which are regularly
replaced, thus providing satisfactory supplies of food.
The hiding-places may, e.g., be hollows or recesses in soft species
of rock, coral reefs or loose stones. These rocks will be capable
of providing overhang and hiding-places while at the same time the
current of water supplies food. The result of this therefore is
that there are large areas along the coast which are not suitable
for lobsters even though the food supply may be adequate.
Structures in which lobsters are accommodated are known from Japan
amongst other places. These consist of compact pyramidal structures
of concrete with a plurality of openings in the external surfaces.
However, these structures have many drawbacks. The compact construction
makes deployment on the seabed complicated due to the great weight.
They have small surfaces in relation to the volume of the structure,
which results in a relatively small number of hiding-places and
less satisfactory economic exploitation. Moreover, uniform openings
will not take account of the fact that the lobster grows during
its development and needs more room for protection within the same
area.
Thus it is an object of the present invention to provide a lobster
habitat or lobster house which ensures that the lobster is protected
during its entire growth period, and where the openings in the hiding-place
are exposed to adequate supplies of food when the volumes of water
are replaced. In addition the material must be of a type which provides
optimum marine growth. The surfaces must be large in relation to
the volume and the weight/construction should make deployment uncomplicated
with present day technology, in addition to which the deployed structures
should also be stable.
These objects are achieved by the present invention characterized
by the features presented in the claims.
On the basis of the above information, it is important for the
lobster habitat to consist of one or more large surfaces with recesses
perpendicular to the surface, with varying depth and shape of the
openings which must be of different sizes in order to give shelter
to the lobsters at various stages of their growth and where this
lobster habitat can be designed in such a manner that the surfaces
are exposed to replacement of the volumes of water. At the same
time the structure should be simple to deploy on the seabed with
existing maritime technology and once it has been deployed it should
be capable of establishing a stable structure on the seabed with
is not moved by the currents.
The present invention is therefore composed of one or more elements
of water resistant material wherein the element consists of a block
of uniform or varying thickness provided with holes on both of the
two largest opposite surfaces, the main surfaces, of the same or
different depths or through-going holes, in which the circumference
of the holes on the element's main surfaces may have any suitable
shape and different sizes. Since the elements have to be placed
preferably on their edges on the seabed, they can be designed with
the greatest thickness at the end which is intended to form the
base, thus concentrating most of the weight here, while at the same
time the holes on each side of the thicker part can be deeper than
the holes which are formed in the blocks higher up towards what
will constitute the top of the element when it is deployed.
Several elements of this kind, preferably 3-6 most preferably
3 can be connected together to form a star-shaped structure which
will provide large surfaces and small volume, with holes or recesses
of varying size. This shape will be capable of creating turbulent
water movement and thereby providing adequate quantities of nutrient
organisms.
The invention will now be described in more detail with reference
to the figures, in which
FIG. 1 is a perspective view of a lobster habitat element 1 according
to the invention with recesses 2 which have larger openings and
are deeper towards the base of the element which is also thicker
at this end.
FIG. 2 is a plan view of one of the surfaces of the element in
which the openings 2 in the opposite plane are illustrated displaced
in relation to the plane's openings. One set of openings 3 is through-going
FIG. 3 is a section through line III--III in FIG. 2 and demonstrates
that the recesses nearest the base are deeper than those higher
up, a through-going row of holes 3 in addition to which the trapezoidal
appearance of the cross section is demonstrated.
FIG. 4 illustrates an embodiment of the invention in which three
elements are connected together in the form of a star in which the
base of each element is thicker than the top of the element. Hole
4 indicates lifting arrangements which are used when deploying the
structure.
FIG. 5 illustrates the structure as in FIG. 4 but here the elements
are cast individually and connected together by means of a bottom
plate 5 top bracket 6 and safety bolt 7.
FIG. 6 illustrates an embodiment of the invention wherein the elements
which in this case are of uniform thickness are connected in order
to form a mooring.
The individual element according to the invention (FIGS. 12 and
3) can be in the form of a block 1 (FIG. 1) of water resistant material
with two opposite surfaces, the main surfaces, 89 where the block
is thickest at the end which will be the base when it is placed
on its edge, the cross section of the two main surfaces thus having
a trapezoidal shape (FIG. 3). This shape permits deeper holes 2
to be placed at the base while at the same time stabilizing the
element on the seabed, since the base becomes heavier than the top.
Each of the main surfaces 89 is provided with openings 23 of
any shape and size whatever and with recesses inside the element,
or recesses 3 which pass right through the element. These are, e.g.,
arranged in rows (FIGS. 12), but can also be randomly arranged
over the whole element in such a manner that the largest openings
with the deepest recesses are located in the element's thickest
end (FIG. 3). The different sizes of the holes mean that they can
house lobsters of different sizes, and at different stages of development.
In a second embodiment the element or plate has uniform thickness
with holes 23 of varying shape and depth on both surfaces, displaced
in relation to each other in the same way as that illustrated in
FIGS. 1-3. This embodiment of the element is not illustrated.
The elements are made of a heavy, water resistant material, e.g.
concrete. Experience has been built up over a long period of time
with concrete structures in water, such as salt water. In the construction
of artificial habitats for marine organisms concrete is advantageous
since;
the material on the surface consists of Si and Ca ions which are
the main component of natural bottom materials,
the food chain is not polluted,
the weight of the material creates favourable conditions for stability.
In order to augment the stability and weight in the thick part
of the block the upper part can be cast in light aggregate concrete.
The use of a combination of light aggregate concrete at the top
and normal concrete towards the base provides an optimum construction
since it gives maximum marine growth, the weight is reduced and
the stability is ensured.
When deploying the structure it is important that all the surfaces
should be exposed to water in movement and a large number of structures
should be deployed at a good distance from one another in order
to provide an adequate supply of food to all the lobsters which
settle in the habitat. The elements can be situated individually,
but this is usually less suitable for cost-benefit reasons.
A structure in which the weight is low enough for deployment to
be undertaken without problems, and the surfaces exposed to the
surrounding water are large in relation to the volume of the structure
is illustrated by the embodiments in FIG. 4 and FIG. 5. A star-shaped
structure of this kind can comprise from 3-6 individual elements,
preferably 3. Such a shape will provide turbulence in the water
in movement and help to ensure that the turbulent volumes of water
carry food with them and supply this food to all the openings in
the exposed surfaces.
The design according to the invention illustrated in FIG. 4 is
cast as a whole and requires larger transport and crane equipment.
In FIG. 5 a design is illustrated where the individual elements
are driven up to the wharf and connected together on a bottom plate
5 with top bracket 6 and safety bolt 7. The bottom plate 5 top
bracket 6 and safety bolt 7 can be made of any suitable material
which is water resistant and which can withstand the stresses involved.
In a further embodiment the elements or blocks, which are now of
a uniform thickness, are assembled to form a mooring (FIG. 6) which
combines great weight with the possibility of providing the right
conditions for the growth of lobsters. This structure will be constructed
of normal concrete alone, or a combination of normal concrete and
light aggregate concrete, with the latter in the top part of the
mooring. This design will be suitable for attaching to wharfs and
buoys for use by private house and cabin owners while at the same
time providing optimum conditions for the growth of marine organisms,
such as crustacea. |