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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to the growing of foodstuffs in general and
in particular to a method and apparatus for growing progressively higher
trophic levels of marine life in a closed and ecologically balanced
system.
Systemculture is a term coined to describe in a single word the essence of
the present invention. It comprises multiple trophic levels and is a
system of aquaculture which, unlike its predecessors, requires a
continuous management of the interrelationship between the several trophic
levels in the system.
While the trophic levels in a typical ecologically balanced food chain are
many in number, they may be considered broadly in two categories. The two
categories are plant life and plant-eating animals. Of principal interest
presently is the growing of phytoplankton for food for oysters and clams
and the collection of their effluent from the feeding for the growing of
seaweed, which is harvested for providing a fertilizer or used as a food
for omnivore -- e.g., lobster, shrimp, turtle, fish such as mahimahi, etc.
Heretofore, there have been, and indeed there are presently, two forms of
well known aquacultures: a monoculture and a polyculture.
An example of a monoculture is the growing of seaweed and turtles in
separate reservoirs. An example of a polyculture is the growing of turtles
and seaweed together in the same reservoir. In the monoculture, the
seaweed and turtles are fed nutrients and harvested for a market. This is
analogous to the maintaining of cattle in a system feed lot wherein the
cattle are maintained in an enclosure and feed, enriched with certain
supplements, is transported to the cattle and fed to them in controlled
amounts. In the polyculture, the turtles feed on the seaweed and in turn
discharge wastes into the pond, which feeds the seaweed. Both the turtles
and the seaweed are harvested as their respective volumes and numbers
exceed the capacity of their enclosures.
In the monoculture there is a degree of management in that control is
exercised over the amount of nutrients fed to the product to be marketed.
There is, however, typically no attempt made to use the wastes and
effluent of one to feed or otherwise produce the other.
In contrast, in a polyculture, the wastes and effluent of one trophic level
are used to feed or otherwise produce the trophic level on which it feeds
and, in a more sophisticated system, to feed or otherwise produce a higher
trophic level. There is, however, no attempt made to control the amount of
nutrients supplied by the one to the other, nor is there any control
exercised over the manner in which the nutrients are supplied. The system
is typically wholly contained and self-regulating.
While it is clear that a natural food chain is effective, it is equally
clear to the point of being axiomatic that nature is not always the most
efficient.
A principal object of the invention is, therefore, a system of growing
seafood which is highly efficient.
The present invention, while applicable to the growing of multiple species
of marine life, will be described principally with respect to the growing
of shellfish, such as oysters, clams and lobsters, and the production of
their nutrients.
Oysters, for example, feed most productively on certain species of
phytoplankton. Phytoplankton is a small, microscopic, floating plant. It
can't swim on its own. It is, in its natural state, when healthy,
suspended in the sea. It grows, or possibly more correctly stated,
multiplies by dividing. Its rate of growth or multiplication in nature is
such that it reproduces about every 16 hours, depending on its species,
the level of its nutrients and the temperature of its environment. The
species of principal interest are Nitzchia sp., Thalassiosira pseudonana
Skeletonema costatum, Phaeodactylum tricornutum, and Tetraselmis sp.
Chaetoceras sp. Cryptomonas sp., Isochrysis sp. and Monochrysis sp. are
good feed for larvae. The nutrients on which they depend in nature include
nitrates, phosphates, silicates and trace elements. Dissolved oxygen, pH
and ammonia levels must also be controlled and the temperature range
within which they have their maximum growth rate is 24-26.degree. C.
Temperatures within this range are typically found in the tropics. It is
well known, however, that, while having an abundance of sunshine, the
tropics are deficient in the nutrients necessary for oyster growth. They
are deficient in nutrients because the nutrients are consumed rapidly and
are not replenished quickly enough due to the high growth rates which
prevail in the tropics, thus leaving to the colder climates the majority
of the present oyster production, albeit at much slower growth rates.
At the present time, in the commercial shellfish industry, oysters are
removed from the bottom of an oyster bed by dredging or tonging. Dredging
is accomplished by scooping the oysters from the bottom of the oyster bed
with mechanical shovels or by means of a vacuum. Tonging involves the use
of long tongs which are manually manipulated by a person standing in a
flat-bottom boat for grasping the oyster and raising them from the bottom
of the oyster bed.
To prepare an oyster bed for the growing of oysters, oyster shells from a
prior catch, or other clean surfaces, are laid on the oyster bed. When the
seeds of the females have been fertilized by the sperm, the resulting
larvae (spat), after a short period of random swimming about, attach
(settle) themselves to the shells or other clean surfaces, undergo a
metamorphosis and begin maturing as an oyster. Often a number of "spat"
will "settle" on a single oyster shell. It will be understood that, if a
number of oyster larvae attach themselves to the same clean surface,
oyster clusters will form. The formation of oyster clusters makes it
difficult during harvest to shuck the oysters and to sort them according
to size. It is also hard to clean the mud and slit from the bottom of the
oyster bed from the oysters if they are clustered.
Another method of growing oysters is called racking. In racking, oyster
shells from a prior shucking are pierced and strung on strings. The
strings are suspended from rods or the like forming racks in the ocean.
Oyster spat is allowed to settle on the oyster shells attached to the
strings. "Racking" of oysters shortens the growing period to market size
of the oyster from approximately 3 years to 18 months, eliminates -- or at
least reduces -- cleaning and avoids the time-consuming and costly
inefficiencies of dredging and tonging. In racking, however, there are
certain disadvantages which exist and which are commo to all present
ocean-based commercial seafood growing operations. These are destructive
weather, predation (sharks, etc.) pollution, problems of legal ownership,
government regulations, the high cost of operation and, very importantly,
lack of food control in terms of amunt, type and location relative to the
location of the growing animals.
Land-based aquaculture eliminates many of the above mentioned problems and
disadvantages inherent in traditional methods of fish farming. Moreover,
the potential tonnage per hectare of a well organized land-based
aquaculture is so high that great areas of ocean really aren't needed. Why
aquatic efficiency is so great is not clearly understood. However, there
are some reasons which may be accepted. First, production gets a boost
from the aquatic relief of gravity and friction. To use an analogy, if a
poultry farmer wants to cycle manure out to a field, grow grain there and
bring the feed back, he must use shovels, wagons, spreaders, harvesters,
storage bins and conveyor belts. The oyster farmer, using the method and
apparatus of the present invention, only needs to lift a weir board and
let the flow of water do the rest. A particle of effluent from an oyster
at a site can be carried a mile down therunway to fertilize a cell of
phytoplankton which, in turn, can be carried a mile back to be absorbed by
another oyster.
Another factor in the aquatic efficiency is the structure and physiology of
marine plants and animals. For example, seaweed can double its weight
every 60 hours because all of its energy is going to growth and not to the
stalk and stem that are needed for so much of the bulk of terrestrial
plants.
Because of these factors, the clear need for an expanded world food
production, and the ever increasing limitations on land production due to
an ever decreasing availability of petroleum-based fertilizers and
fuel-demanding irrigation, a number of individuals and companies have been
conducting research on various forms of acquaculture and mariculture. Most
of this research, however, has been based on relatively small-scale
experiments under laboratory conditions. While there have been proposals,
few entirely integrated large-scale, wholly land-based, commercially
significant aquaculture systems have been attempted. For example, in U.S.
Pat. No. 3,735,736 there is proposed a method and apparatus, using a
system of trenches and the warm water effluent from a nuclear plant for
growing shrimp. It is mentioned that the shrimp are fed periodically, but
there is no discussion of how the food is produced, no disclosure of a
method or means for producing the food continuously and no method or means
disclosed for controlling the type of food, the amount of food delivered
for feeding to a particular animal or small group of animals and the time
of feeding.
To produce seafood in commercially significant quantities, it is considered
essential that the nutrients for feeding the seafood be produced on a
large scale in a controlled manner, and continuously. For example, to feed
oysters, clams and the like, this means that large-scale algal ponds or
reservoirs are required in which phytoplankton can be maintained in a
state of "bloom" uninterruptedly for long periods of time, such as 30 to
60 days, and while a high percentage of its volume (such as one-half to
two-thirds) is "harvested" continuously.
Heretofore, the largest man-made algal pond believed to have been attempted
to be maintained for growing phytoplankton to feed seafood was about
12,000 gallons, or less than 1/8 acre in area and about 3 feet deep. So
far as is known, however, there has been no report that the attempt was
successful. If, indeed, the attempt was not successful, it would not be
surprising, because large bodies of water are different from small bodies
as a growing medium and heretofore were vastly more difficult to manage,
especially when the management involved the maintenance of a large-scale
continuous flow algal pond having a high density of phytoplankton, such as
a density exceeding 10.sup.5 organisms/liter.
SUMMARY OF THE INVENTION
In view of the foregoing, principal objects of the present invention are a
method and apparatus for growing seafood efficiently in commercial
quantities in a wholly land-based, ecologically balanced aquaculture
system.
Generally, five kinds of facilities are provided to farm in this fashion.
First, there are provided a source of brackish or salt water and an
inexpensive method of pumping the water. Second, there is provided a
plurality of reservoirs for growing microscopic marine plants. Third,
there is provided a plurality of production trenches. Each of the
production trenches is adapted for removably receiving inserts chosen
especially for the crop selected for that particular trench. For example,
clams and oysters require stacks of trays having closed side walls
orientated so that plankton-rich water passes vertically through them in
the manner of a filter bed. Turtles, on the other hand, are provided
partitions which are placed at intervals in the trenches confining groups
of turtles into small aquatic feed lots. Lobsters and octopuses are
provided long facing rows of honeycomb units forming numerous caves giving
each animal a place to hide and to feed the passing current. Fourth, there
is provided a means for transporting the water between the reservoirs and
a trench and, as it leaves the trench, to a purging pond containing
seaweed, for which the waste in the trench effluent is a nutrient.
Finally, there is provided conventional farm equipment, such as flat-bed
trucks and hoists, which are required for harvesting the crops from the
trenches.
The advantages of a land-based aquaculture system, as described, are
manifold. Among the advantages is freedom from pollution and disease, such
as has totally destroyed entire oyster crops in various parts of the world
in recent years. Similarly, there is no problem with predators such as
sharks, strong currents or destructive weather nor are there any questions
of legal ownership or government regulations as are now used for
regulating seafood catches at sea. Moreover, growth weight and size can be
controlled by controlling the amount and type of food and the temperature
of the water used. Also, various species of seafood can be grown
simultaneously or in successive growing periods depending on market needs.
More specifically, in a present embodiment of the invention, there is
provided a source of phytoplankton. The source is a relatively shallow,
uncovered well, as of five feet deep, located adjacent to an ocean, which
collects water and phytoplankton. The phytoplankton density in the well is
typically between 10.sup.1 to 10.sup.3 organisms/liter. Near the
phytoplankton well there is provided a plurality of inoculating pools.
Each of the pools has a capacity of about 4000 gallons and is coupled to a
source of brackish or salt water. The source of brackish or salt water is
a deep well as of 60 feet deep or the ocean. To fill the inoculation
pools, 3500 gallons of water from the deep well are pumped in each of the
inoculating pools and the water thus placed is inoculated with 500 gallons
of phytoplankton-laden water from the shallow well. Thereafter the water
in the pools is mixed with fertilizer daily until the phytoplankton
density level reaches 10.sup.7 to 10.sup.8 organisms/liter. Near the
inoculating pools there is provided a reservoir having a 21/2 foot
.times. 1/4 acre capacity and a plurality of larger volume reservoirs
having 21/2 feet acre capacities. After the density of the phytoplankton
reaches 10.sup.7 to 10.sup.8 organisms/liter in each of the inoculating
pools, 21/2 pools are emptied into the 21/2 foot 1/4 acre reservoir for
inoculating the 21/2 foot 1/4 acre.
Thereafter the 21/2 foot 1/4 acre reservoir is fertilized daily until the
phytoplankton density reaches a level of 10.sup.7 to 10.sup.8
organisms/liter. When the 21/2 foot 1/4 acre reservoir reaches a
phytoplankton level of 10.sup.7 to 10.sup.8 organisms/liter, approximately
one fourth of its volume is used to inoculate each of the 21/2 foot acre
reservoirs. Thereafter, each of the 21/2 foot acre reservoirs is
fertilized daily until is phytoplankton density level reaches a level of
from 10.sup.7 to 10.sup.8 organisms/liter.
Once a reservoir is in "bloom" -- i.e., has reached a desired phytoplankton
density level as of from 10.sup.7 to 10.sup.8 organisms/liter -- the
phytoplankton is removed at a rate of from one half to two thirds of the
volume of the reservoir and transported through the production trenches
for feeding seafood contained in trays or other inserts contained therein.
From the trenches, the efflunt including the wastes are transported to a
purging pond containing seaweed. The wastes are nutrients for the seaweed
and the seaweed feeds on the wastes and purges the water.
In the purging pond there is provided a deep discharge well, as of 60 feet
deep. The well is located in a position which prevents uncontrolled
contamination of the brackish and salt water source and phytoplankton
source. In this fashion, the water discharged through the well may be
returned to the system after natural filtration in the earth.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present
invention will become apparent from the following detailed description of
accompanying drawings in which:
FIG. 1 is a flow diagram of a land-based aquaculture system according to
the present invention.
FIG. 2 is a three-dimensional diagram of a land-based aquaculture system
according to the present invention.
FIG. 3 is a plan view of a secondary algal reservoir according to the
present invention.
FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 3.
FIG. 5 is a plan view of four algal reservoirs according to the present
invention.
FIG. 6 is a perspective view of a production trench according to the
present invention, with or without inserts.
FIG. 7 is a plan view of the trench of FIG. 6.
FIG. 8 is a cross-sectional elevation view of the trench of FIG. 7.
FIG. 9 is a plan view of an alternative production trench according to the
present invention.
FIG. 10 is a cross-sectional elevation view of the trench of FIG. 9.
FIG. 11 is a perspective view of a pallet according to the present
invention for supporting inserts in the trenches of FIGS. 6, 7, 8, 9 and
10.
FIG. 12 is a perspective view of a tray insert according to the present
invention.
FIG. 13 is a perspective view of a honeycomb enclosure insert according to
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is provided in a system in accordance with the
present invention a source of salt or brackish water 1 and a source of
phytoplankton 2. The source 1 is a deep well as of 60 feet deep or the
like. The source 2 is a relatively shallow uncovered well as of five feet
deep and adjacent to a natural source of phytoplankton such as an ocean.
The source 2 preferably has a natural density of phytoplankton therein of
at least 10.sup.1 to 10.sup.3 organisms/liter. Near the sources 1 and 2
there is provided a plurality of 4000-gallon inoculation pools 2A, a
plurality of algal reservoirs 3, each having a capacity of from 1/4 to one
acre and 21/2 feet deep, one or more production trenches 4, a plurality of
purging ponds 5 and a source of fertilizer 6. Pumps, such as Archimedes
screws or the like (not shown), are used for pumping water from one
location to another in the system.
Before production in the trenches begins, the density of the phytoplankton
in the reservoirs 3 is caused to equal or exceed 10.sup.5 organisms/liter
and is preferably between 10.sup.7 and 10.sup.8 organisms/liter. To
achieve these high density levels, the inoculating pools 2A are each
filled with 3500 gallons of water from the source 1, as shown by the
dashed arrow 1A and 500 gallons of water from the source 2 as shown by the
dashed arrow 2B. The pools 2A are thereafter fertilized daily from the
source 6, as shown by the dashed arrow 6A until each one of them achieves
a phytoplankton density level of about 10.sup.7 to 10.sup.8
organisms/liter.
When the pools 2A have achieved the desired density level, the 21/2 foot
1/2 acre algal reservoir is filled from the source 1, as shown by the
solid arrow 1B and inoculated with the water from two and a half of the
pools 2A. Thereafter, the 21/2 foot 1/4 acre reservoir is fertilized daily
from the source 6, as shown by the dashed arrow 6B until it achieves a
density level of 10.sup.7 to 10.sup.8 organisms/liter. When the 21/2 foot
1/2 acre reservoir reaches the desired density levels, each of the 21/2
foot acre reservoirs are filled from the source 1 and inoculated with
water from about one-fourth of the 21/2 foot 1/4 acre reservoir. After the
inoculation, the 21/2 foot acre reservoirs are fertilized daily until they
reach a density level of between 10.sup.7 to 10.sup.8 organisms/liter.
As will be described further, once the reservoirs 3 have obtained the
desired density levels, production begins with the continuous
transportation of water from the source 1, into the reservoirs 3 and from
the reservoirs 3 through the trenches 4 as shown by the solid arrows 1B
and 3A. The water is being transported at a controlled rate of from
one-half to two thirds of the volume of each of the reservoirs 3 daily. It
may be well to note that once in bloom, all of the reservoirs, including
the smaller 21/2 foot 1/4 acre reservoir is used in production. The amount
of water which is transported through a particular trench is also
controlled and depends on the amount of seafood being grown therein, its
size and feeding capacity.
From the trenches 4, the effluent is transported, as shown by the solid
arrow 4A, to a purging pond 5 containing seaweed and having a deep
discharge well (not shown). The seaweed, as will be further described,
feeds on the wastes in the effluent from the trenches 4 and purges the
water. The deep discharge well serves to discharge the purged water into
the earth at a location which precludes an undesired contamination of the
sources 1 and 2. Alternatively, a portion of the discharge from purging
pool 5 may be controllably recirculated through the trenches 4, as shown
by the dashed arrow 5A for maximizing the use of the nutrients in the
water.
The arrows used to illustrate the present invention in FIG. 1 are dashed
and solid to represent differing levels of activity. The dashed arrows
represent activities which occur periodically or only on occasion. The
solid arrows represent activities which are continuous. It is to be
understood, however, that if an algal reservoir "crashes" it is necessary
to interrupt the continuous operation until the reservoir is again in
bloom by the method described above.
Referring to FIG. 2, there is shown in a perspective diagram an
illustration of the continuous flow portions of a typical land-based
aquacultural complex according to the present invention, comprising a
source of water 10 which corresponds to the source 1 of FIG. 1. The
inoculating well 2 and pools 2A and source of fertilizer 6 of FIG. 1 are
indicated only generally. As in the illustration, the source 10 is a deep
well 10A which may or may not be covered, depending on the prevailing
conditions. Depending on the height of the water, the water from the
source 10 is pumped into flume 11 by means of one or mre Archimedes screw
pumps 12 or 13 or the like. Each of the pumps 12 and 13 is driven by means
of a five-horsepower motor 14 and 15. Electricity for driving the motor 14
and 15 is generated by means of 6KW windmill powered generator assembly
16.
Water from the source 10, which is pumped into the flume 11, flows through
the flume 11 to a pair of algal reservoirs 20 and 21. In an actual
embodiment, the reservoirs 20 and 21 each typically comprises from
one-quarter acre to one acre in area and is approximately 21/2 feet deep
for containing about 815K gallons of water per acre. The bottom of the
reservoir comprises asphalt and coral rock. The side walls comprise
unlined concrete members.
In fluid communication with the reservoirs 20 and 21, by means of a pair of
flumes 22 and 23, is a trench 24. Trench 24 is typically rectangularly
shaped and approximately 31/2 feet deep and has, extending along its
lateral edge opposite the flumes 22 and 23, a gutter 25. Gutter 25 serves
as a trench effluent gutter and is provided for receiving effluent from
the trench 24 through a pair of weirs or pukas 26. Suspended in the center
of the trench 24 and extending in a plane parallel to the major axis
thereof, there is provided a septum 27. Septum 27 comprises a rubber sheet
or the like and is suspended in the plane in a vertical orientation by
means of a truss framework 28. Framework 28 typically comprises a
plurality of inclined rafters 28A abutting at their upper ends a
horizontally extending board from which the septum hangs. For reasons
which will be described below, framework 28 serves to suspend the septum
27 such that its bottom is held a predetermined distance, as of 5 inches,
above the bottom of the trench 24. On either side of the septum 27 space
is provided in the trench 24 for receiving and containing a plurality of
inserts 29. The inserts 29, as shown in FIG. 2, are screened trays, having
closed sides and an apertured bottom, for containing oysters. The trays 29
will be further described below, as will other types of inserts for
containing other types of seafood.
In fluid communication with the discharge gutter 25 there is provided a
purging pond 30. Pond 30 is provided for receiving water from the gutter
25. At the output end of the purging pond 30 there is provided a discharge
pipe or the like 31. Pipe 31 is provided for discharging effluent from the
purging pond and for returning the purged effluent to the water source 10,
either directly or via a natural filtration process through the earth. As
will be apparent, only a partial direct return of purged effluent should
be employed to prevent or reduce loss due to non-purged contaminants.
Referring to FIG. 3, there is provided an algal reservoir 40. Reservoir 40
has a plurality of side wall members 44, 45, 46 and 47 of unlined concrete
and a bottom 48 of asphalt and coral rock, and corresponds to one of the
algal reservoirs 20 and 21 of FIG. 2. At one end of reservoir 40 there is
provided a fluid inlet 41. Inlet 41 is provided for coupling the reservoir
40 to a source of phytoplankton and fertilizer. At the opposite end of the
reservoir 40 there is provided a fluid outlet 42. Fluid outlet 42 is
provided for coupling the reservoir 40 to a seafood production trench,
such as the trench 24 of FIG. 2 or a trench, as will be described below.
At one or more suitable locations within the interior of the reservoir 40
there is provided a circulation impeller apparatus 43. Apparatus 43, for
example, may comprise a 3-foot impeller 43 A, which is driven at a low rpm
by a low-horsepower electric motor 43B, as of 5 hp. The apparatus 43
serves to circulate the water in the reservoir 40. A typical reservoir 40
is from o/4 to one acre in area and 21/2 feet deep for containing about
815,000 gallons per acre. As will be apparent, the reservoir 40 may be
either a primary or a secondary reservoir and, in some applications, could
be adapted to serve as a source of phytoplankton.
Referring to FIG. 4, the juncture of the side-wall members 44, 45, 46 and
47 with the bottom 48 of the reservoir 40 is provided to have a curved
surface 49. Curved surface 49 is provided for reducing the opportunity for
dead space in the reservoir 40 and to facilitate the circulation of water
therein in the direction of the arrows.
Referring to FIG. 5, there is provided a plurality of algal reservoirs 50,
51, 52 and 53. Like the reservoir 40 of FIG. 3, each of the reservoirs
50-53 comprises concrete side-wall and asphalt and coral rock bottom
members. In the center of the reservoirs 50-53 there is provided a weir
box 54. Weir box 54 is provided with four outlets 55, 56, 57 and 58. Each
of the outlets 55-58 is located to be in fluid communication with an
associated one of the reservoirs 50, 51, 52 and 53, respectively. Passing
through the center of the reservoirs 50-53, between the reservoirs 50 and
51, and reservoirs 52 and 53, respectively, there is provided a flume 59
and between the reservoirs 50 and 51 a flume 59A. The weir box 54 is
provided for receiving water from the flume 59A, which is connected to a
source of water such as the source 10 of FIG. 2, for distributing it into
the reservoirs 50-53 through an associated one of the weir box outlets
55-58. The flume 59 is provided for transporting water from the reservoirs
50-53 to a production trench and, accordingly, each of the reservoirs is
coupled to the flume 59 by an associated weir 59B. In practice, each of
the reservoirs 50-53 is also provided with a circulation apparatus as
described with respect to apparatus 43 of FIG. 3 and a specially adapted
bottom-side wall contour as described with respect to the surface 49 of
FIG. 4.
Referring to FIG. 6, 7 and 8, there is provided a single-septum seafood
production trench 60. In production trench 60 there is provided a pair of
sloping side walls 61 and 62. Side walls 61 and 62 slope upwardly and
outwardly from a horizontally extending bottom 63. As will be apparent,
the side walls 61 and 62 are sloping to facilitate the insertion and
removal of inserts in and from the trench. Extending along the lateral
edges of the trench 60 there is provided a pair of gutters 64 and 65.
Gutter 64 is provided at each end with a pair of fluid passageways 66 and
67. Gutter 65 is provided with a similar pair of oppositely positioned
fluid passageways 68 and 69. Each of the passageways 66, 67, 68 and 69 is
provided to be removably fitted with a weir board for controlling the flow
of water therethrough from and into a pair of flumes 70 and 71 located,
respectively, at opposite ends of the trench 60. Located in the center and
extending in a plane parallel to the major axis of trench 60 is a septum
72. Septum 72 is supported from a truss system 73. Truss system 73, which
is identical to the truss 28 of FIG. 2, supports the septum 72 a
predetermined distance, as of 5 inches, above the floor 63 of the trench
60 for allowing water to pass therebeneath, as will be described below.
Referring to FIGS. 9 and 10, there is provided, in an alternative
embodiment of a trench according to the present invention, a dual-septum
trench 80. Trench 80 is provided at opposite ends with a pair of flumes 81
and 82. Extending along the lateral edges of trench 80 is a pair of
gutters 83 and 84. Sloping downwardly and inwardly from gutters 83 and 84
there is provided, respectively, a pair of sloping walls 85 and 86. Walls
85 and 86 extend upwardly and outwardly from a bottom member 87. The walls
85 and 86 and bottom member 87 are lined with a nylon-reinforced butyl
rubber liner of a quality suitable for containing potable water. Located
in the center of the trench 80 and extending in a plane parallel to the
major axis thereof is a pair of septum members 90 and 91. Members 90 and
91 are supported above the bottom member 87 a predetermined distance, as
of 5 inches, for permitting water to flow therebeneath in a manner and by
a means (not shown) substantially equivalent to the truss system of FIGS.
2 and 6-8. In practice, the members 90 and 91 are spaced approximately two
feet apart and at one end thereof there is provided a recirculating
impeller assembly 92 and a pair of weir outlets 93 and 94. At opposite
ends of the gutter 83 and in communication with the flumes 81 and 82,
there is provided a weir fluid passageway 95 and 96. Similarly, at
opposite ends of the gutter 84, for providing fluid communication with the
flumes 81 and 82, there is provided a pair of weir fluid passageways 97
and 98.
Referring to FIG. 11, there is provided for supporting the inserts to be
described in the trenches 60 and 80 an insert-supporting pallet assembly
100. Pallet assembly 100 comprises a plurality of open-ended, adjacent
box-like structures 101, 102, 103 and 104. Each of the structures 101-104
comprises a plurality of permanent wall members 105 and a removable wall
member 106.
Referring to FIG. 12, there is provided a tray insert 110. Insert 110 has
four side-wall members 111, 112, 113 and 114, and a bottom member 115. The
side-wall members 111-114 are closed and the bottom member 115 is provided
with a plurality of holes 116 for allowing the passage of water
therethrough. The size of each of the box members 101, 102, etc. of
assembly 100 and the size of the insert 110 of FIG. 12 are substantially
identical such that the insert 110 rests on top of the side-wall members
105.
Referring to FIG. 13, there is provided, in an alternative insert for use
in the trenches 60 and 80 of the present invention, a honeycomb insert
120. Insert 120 is provided with a plurality of closed cavities 121 and is
inserted in the bottom of either of the trenches 60 or 80, as will be
described.
Referring again to FIG. 1, in practice, as briefly discussed previously, in
an actual embodiment of the present invention, the source of water 1 and
source of phytoplankton 2 are wells which are located adjacent to an
ocean. The source 2 is simply a relatively shallow ditch, as of 5 to 6
feet deep, which extends down into the earth to a depth sufficient to
expose the natural water level in the earth. Water filters through the
earth between the ocean and the well and is collected in the well. At the
same time it carries with it phytoplankton. Usually, the well is left
uncovered. As a consequence, phytoplankton and other marine
micro-organisms are also carried to the well by the winds. This feature of
the well undoubtedly allows for a plurality of species of micro-organisms
to exist in the well simultaneously.
In the well, as in an ocean or bay having a relatively rich mixture of
phytoplankton and water, the naturally occurring density of the
phytoplankton is found to be between 10.sup.1 and 10.sup.3
organisms/liter. This density is generally much too low for growing
seafood in commercially significant quantities rapidly. Accordingly, steps
are taken to raise the density levels and one of the steps taken is to
control the temperature of the water by providing properly sized algal
reservoirs. This step is taken because it has been found that if the
ambient temperature of the water in the reservoirs is maintained between
20.degree.-26.degree. C., the phytoplankton, if also properly fed, will
grow by division and raise its density levels in a reproduction cycle
having a period of approximately 16 hours.
To determine the density of the phytoplankton in the reservoirs 2 and 4,
the density may be approximated visually. For example, it may be done by
an operator who places his or her arm in the algal reservoir. If the
reservoir contains phytoplankton at a density of approximately 10.sup.7
organisms/liter, the operator, depending on the ambient light, typically
will be unable to see his fingers when the arm is placed into the water to
a depth of the biceps. When the density of the phytoplankton reaches a
level of 10.sup.8 organisms/liter, the operator, again depending on the
level of the ambient light, will no longer see the ends of his fingers
when the level of water reaches his wrist. Frequently, however, more
scientific measures of density are also employed using conventional
methods.
To insure that the phytoplankton is properly fed, fertilizer is added daily
to each 21/2 foot acres of water in the following quantities:
sodium nitrate: 22.78 lbs.
ammo-phosphate: 2.05 lbs.
calcium silicate: 34.18 lbs.
mineral mix: 4.56 lbs.
chicken manure: 23.84 lbs.
For ease of distribution, the sodium nitrate, ammo-phosphate, calcium
silicate and mineral mix are mixed with the chicken manure in water to
form a solution. The solid materials, typically in pellet and powder form,
are mixed in the water b | | |
