CA2102539A1

CA2102539A1 - Integrated live fish harvesting and holding system

Info

Publication number: CA2102539A1
Application number: CA002102539A
Authority: CA
Inventors: Clarence E. Button
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-11-05
Filing date: 1993-11-05
Publication date: 1995-05-06

Abstract

ABSTRACT OF THE DISCLOSURE
A novel fyke net is provided herein. It includes a trap body tunnel open at one end and including a plurality of inward narrowing funnels. wings or leaders in the form of panels of vertically hung netting extend from the trap body and are adapted to be disposed along the river or lake bottom. Wing supports in the form of stakes are adapted to be erected into the stream or lake bottom and are adapted to maintain the shape and position of the wings and to keep them erect in higher velocity water currents. A collection bag in the form of an additional closed-end funnel of netting, situated behind the body of the net at the narrow end of the funnels. This fyke net is used together with a holding cage. Such holding cage includes a containment cage in the form of a frame of structural material and a mesh covering, and a flexible bladder attached to the containment cage, and into which a gas may be injected to provide buoyancy for the containment cage.

Description

2 1 ~

This invention relates to apparatus for the harvesting and holding of live fish.
The collection of fish in flowing waters, using fixed gear, has long been considered a desirable method of harvesting a number of highly valued migratory fish species. Such species as Arctic char, salmon, trout, striped bass and eel spend some portion of their life cycle in fresh water and it is there where they may be conveniently collected. The live collection and holding of some of these species is desired for purposes of securing higher market prices or their use as sources of spawning material for stock enhancement.
The collection of these and other freshwater species has been conducted for millennia and as a consequence of the variability of environments from which they have been harvested, an astonishing array of harvesting systems have been developed. These designs however, are typically used in the broader, somewhat slower moving rivers characteristic of the low topography of coastal plain states on both sides of the Atlantic Ocean. Such ideal conditions are not present in all regions and few designs for river harvesting devices are suitable for use in faster flowing rivers.
Fixed gear by its very nature is attached or anchored to some bottom substrate and is normally deployed in shallow rivers, estuaries and coastal areas. It is in these areas that the largest concentrations of many highly valued freshwater and coastal fish species abound. Major ~,~v'~

advantages of using fixed gear are: the low cost of operation; proximity to the shore and processing -- capability; and the capability of harvesting a live and consequently absolutely fresh and higher valued raw material. One specific design of net, named the fyke net has been developed and extensively used in these environments.
Several difficulties adversely influence the effectiveness of harvesting gear in these coastal, estuarine and freshwater environments.
One of such difficulties involves high velocity waters. Some fish species move or migrate only when the water levels are adequately hiqh so as to permit passage up a river or along the reaches of an estuary. These higher water levels are frequently associated either with precipitation or tidal current-induced increases in water flow velocity.
Another such difficulty involves debris. During periods of higher water levels and velocities debris, e.g., leaves, branches and other plant material are washed into the streams, rivers and estuaries. This detritus has two adverse effects on harvesting effectiveness in these waters. Larger material, e.g., logs, can remove or destroy the harvesting device. On the other hand smaller materials, e.g., leaves, can block the wings and body of the existing harvesting devices causing an obstruction of water flow and consequent insurmountable strain on the 2 ~ 3 ~
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netting material which either is destroyed, washed away or is distorted to a non-functional state.
Yet another difficulty involves high volume harvest.
In temperate waters, although diversity of fish species is significantly less than in tropical regions, the enormous concentrations of temperature species in spawning or feeding migrations or aggregations requires that effective harvesting devices be capable of accommodating and handling large volumes of catch within short time frames.
A still further difficulty involves non-target by-catch. Most existing devices are non-selective in the species of fish they harvest, with the exception of limits imposed either by the size of the mesh which they are fabricated, for quite small fish, or the dimension of the entrance funnel which may prevent large organisms from entering.
Finally, there are regulatory restrictions as a consequence of the previous difficulties with non-target by-catch. Consequently, fisheries managers and regulators have required either that the use of fyke nets not be allowed in lakes or ponds and then only during brief seasons when the most valued non-target species are not present in estuarine or riverine waters. The most liberal permitted usage is a deployment in which the net does not occlude or harvest from at least one-third of the main channel of the river or estuary.

2 11 ~33 ` 4 Some prior patents which may have some relevance to the present invention include the following:
1) U.S. Patent No. 4,170,196 (October 9, 1979) YONEYA, KIYOO, Kurobe, Japan;
2) U.S. Patent No. 4,079,698 (March 21, 1978) Inventor: NEFF, GREGORY N., Dobbs Ferry, NY
BARRETT, PAUL C., Homestead, FL

3) U.S. Patent No. 4,003,338 (January 18, 1977) Inventor: NEFF, GREGORY N., Dobbs Ferry, NY
BARRETT, PAUL C., Homestead, FL

4) U.S. Patent No. 3,852,908 (December 10, 1974) Inventor: CHRISTOPHER, JOHN P., Islamorada, FL

5) U.S. Patent No. 4,244,323 (January 13, 1981) Inventor: MORIMURA, SHINJI, Yokohama, Japan and 6) Canadian Patent No. 1,093,401 (January 13, 1981) Inventor: STREICHENBERGER, RUDOLPHE, Devin, France Existing designs of fyke nets are either submerged, displaced or distorted by higher velocity water flows.
Existing devices have no means to handle large volumes of catch and have been known to become bloated with catch, both to the detriment of the live fish and with such weight that it is unmanageable and a significant proportion of the harvest is lost. Existing devices have demonstrated significant problems of catching non-target species which difficulty has caused restrictions on their season and extent of use. Accordingly, the principal aim ~f the present invention is to provide improvements to th~

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:~, 5 traditional design of fyke net to mitigate or substantially eliminate these difficulties.
This invention is a highly effective harvesting and live holding system for fish species, useful in static waters but particularly effective in flowing waters. The invention comprises a system with two mechanical components and a method of use which achieves the above objectives.
The present invention provides a fyke net comprising:
a) a trap body tunnel open at one end and including a plurality of inward narrowing diownstream funnels; b) wings or leaders in the form of panels of vertically hung netting extending from the trap body and adapted to be disposed along the river or lake bottom; c) wing supports in the form of stakes adapted to be erected into the stream or lake bottom and adapted to maintain the shape and position of the wings and to keep them erect in higher velocity water currents; and d) a collection bag in the form of an additional closed-end funnel of netting, situated behind the body of the net at the narrow end of the funnels.
The present invention also provides a holding cage comprising: a) a containment cage comprising a frame of structural material and a mesh covering; and b) a flexible bladder attached to the containment cage for loading with a gas thereby to provide buoyancy for the containment cage.
The first mechanical component of the system is a harvesting device which incorporates novel improvements on an age-old design of the fyke net. The harvesting device component of the system has four distinct but integrated ~1~2~
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elements. The first element is a trap body which is a tunnel of netting, either of rectangular, square or round cross-section which is open at one end which serves to attract and trap the fish by means of inward narrowing downstream funnels to prevent the escape of the fish which have entered the trap.
The second element is a plurality of wings or leaders, which are long panels of vertically hung netting extended from the body of the net along the river or lake bottom to intercept and guide the moving target fish species to the net body.
The third element is a plurality of wing supports which are vertical stakes which are erected, e.g., by thrusting or hammering them into the stream or lake bottom, and which serve to maintain the shape and position of the .
wings and to keep them erect in higher velocity water currents.
The fourth element is a collection bag which is an additional tunnel of netting, situated behind the body of the net at the narrow end of the funnels which provides space in which volumes of the captured target species may be retained.
The riverine fyke net of this invention is fabricated of non-corroding metals and netting. It is designed and fabricated effectively to divert, funnel and collect fish moving or migrating in estuaries and rivers. The novel improvements below enable a number of functional advantages.

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;; 7 The net wings are designed to be shaped by higher velocity water flows tc provide a smoothly contoured - channel to guide this target species into the body trap section. When used in water depths exceeding the height of the wing, a narrow roof of netting, projecting orthogonally from the vertical wing on either side redirects fish attempting to swim over the wing downwards towards the wing and guides the fish along the wing. The vertical pipe sections of the front frame of the trap body form concave curves towards the rear of the net, conforming to the curvature of the net wings channels formed by the horizontal billowing of the wing netting in the river . . . ~i, ~! .:
current.

The small mouth at the narrow of the funnel-shaped ;

non-return valve at the opening of the trap body has a mechanism for deterring the entry of mammals which may . .
succumb in the net. Such deterrent mechanism is a sharp double prong which originates from the metallic frame . , surrounding this mouth and projects forward into the expanding circumferences of the tunnel.
A specially designed rear frame enables rapid detachment and replacement of collection bags during periods of high volume harvesting activity.
The trap body frames have a square outline, preventing movement of the net in turbulence.
The net mesh is oriented to hang in square mesh configuration on the rear frames to reduce hourglass narrowing of body net tunnel between frames.

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A special apron along the bottom of the net wings is used to secure the wings to the bottom by ballasting the apron, e.g., with available rocks, to prevent escapement of fish under the bottom of the wings.
Specially designed supports shaped as a mirror image figure "4" with double angular extensions from a vertical pole use the force of the river on the net wing to drive the support into the river bottom and enables the net wings to remain erect and functioning as an eel barrier in high-velocity water flow conditions.
A mechanism for facile attachment and removal of the top of the wings at the support stakes constitutes simple rings attached to the top of the wing which fits over the top of the wing support stakes and provide the means whereby the wings may be rapidly dropped from the support takes to place the net in a non-fishing/no-obstruction/non~
operating mode which permits passage of other fish species during periods when movements of target species are not occurring and also provides for the facile cleaning of leaves and debris.
Two unique fabrication methods are used for the production of the fyke net of this invention. One method, the net-to-net panel method, is to insert a small rope through each mesh of net panels to be joined, providing a positive method of joining which ensures greater integrity of the join over that afforded by traditional hand sewing.
The second method, the neit-to-frame attachment method, is by means of inserting or sewing a small rope into the ~1 ~2~39 -.~ i; g , meshes of the netting which are closest to the support frames and the attachment of the small rope to the frame by various means, including plastic or wire wrapping material.
The second mechanical component of the system is a holding cage for the captured migratory fish. This unit has two principal elements. The first element is a containment cage comprising a frame of structural material, e.g~, wood, plastic or metal pipe and a covering material, either closed weave fabric or open mesh configured of netting, plastic or wire mesh. The second element is a flexible bladder attached to the containment device into which air or other gas may be injected to provide buoyancy for the cage.
The submersible fish cage is fabricated of non~
corroding metals and netting. It is designed to contain concentrated aggregations of more sedentary fish species and smaller volumes of more active fish species and particularly throughout the winter months in ice-covered waters of more temperature regions. The novel improvements over traditional designs permit a number of functional advantages, as follows.
The frame is constructed of non-corrodible, hollow tubular structural material which does not absorb water and provides some buoyancy to the unit.
The frame may incorporate a skid or runner which is used both to support the cage frame above the substrate on which it may be dragged and to provide a sled surface for retrieval of the cage from beneath ice.

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`''''' 10 A hatch or means of access to the cage is afforded by the use of a marine-grade "zipper" of non-corrodible material, in a circular or square shape.
The cages may be attached to the body of the harvesting device through means of a standard slot coupling and may be removed from the trap at will to be replaced by another cage or a net collection bag.
The material covering the cage may be either an open fabric, e.g., a fibre, plastic or wire mesh, either with or without a variety of protective coatings or partially of an open fabric and partially of a closed fabric, e.g., a vinyl sheeting (the closed sheeting is useful for protecting the live contents of the cage from excessive light.
The lifting element is a flexible bladder which is attachable to the cage and is of adequate volumetric size so as to lift the cage and its contents when full in fresh water.
The bladder may be equipped with a combination inflow and over-pressure relief valve which permits inflation only up to a marginal value over the ambient water pressure and thereafter shuts off the inflow of air, as well as exhausting excess air upon ascent of the cage.
Alternatively, the bladder may be equipped only with a readily available separate over-pressure relief valve and a simple one-way check valve on the inflation hose to prevent loss of air accumulated in the bladder.

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` 11 The cage units may be attached to one another in series such that a single inflation hose will suffice to ~
lift the whole series of cages. ~ ~:
In the accompanying drawings, Figure 1 is a diagram of an assembled fyke net of this invention in perspective;
Figure 2 is a composite diagram of a front frame detail, both in front elevation and in side elevation; ;
Figure 3 is a diagram of square trap body loop frames with rounded corners in front elevation;
Figure 4 is a composite diagram of a clamp frame for attaching the trap body with the collection bag, both in front elevation and in side elevation;
Figure 5 is a composite diagram of entry deterrent mechanism for small mammals, both in front elevation and in side elevation;
Figure 6 is a diagram in side elevation of a double angle Figure "4" wing support;
Figure 7 is a composite diagram of an assembled submersible cage, both in top plan view and in side elevation;
Figure 8 is a diagram of a tubular frame configuration in perspective;
Figure 9 is a diagram of standard connecting slot for attachment to fyke net;
Figure 10 is a diagram on side elevation of a buoyàncy i .
bladder attached to a submersible cage; and ~ i . ~ S~ "r~ " t-"; ~
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The description of the drawings is self-evident from the legends on the drawings and from the drawings themselves.
Although the two mechanical components of the system (the riverine harvesting net and the submersible live holding cage) are discrete and unique onto themselves, it is the combination of the two mechanical devices and the method of their independent or conjoint use which permits maximum effectiveness of the system. Consequently, the ~method of use of the system is also part of the present invention.
The novel riverine fyke net invention may be utilized in several different configurations, depending on the site and species to be harvested.
A preferred embodiment of the invention is that configured with the body of the trap at the apex or angle of a "V" formed by the extension of two wings of any length. In this configuration, the open mouth of the net body faces the expected approach of tne target species. In locations where there are limitations on the proportion of the river channel which must remain unobstructed, this configuration may be supplemented by the use of another vertical wing or leader upstream of the net and extending across the open region left open by the net below. This is the configuration which is typically used to harvest fish ~,;~", ,.,, .,~,.,.. ,;.".;" ~ ",, ,.. ~ ,."i , ", ~ ",,, " ",,"~,~, ",, ~

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migrating either upstream or downstream in fast flowing streams or rivers.
An alternate configuration, particularly useful in slower flowing waters, utilizes the same body and collection device into which one end of a single wing or "leader" is attached along to the centre axis of the first funnel in the net body at one and projects from the body along the same axis in the other direction as a barrier to fish passage.
A third configuration situates a second body trap and collection bag on the extreme far end of the singular wing or "leader". It is on these latter two configurations that the narrow net "roof" diverting flange on the leaders are most effective.
Multiple units of the complete system of this invention may be used to span large distances of water.
The net may be used in deeper water simply by increasing the height of the wings and the front frame by which the wings are joined to the body of the net.
The submersikle fish cage or a series of cages may be filled with fish to the level permissible by the biology of the particular species, and with the buoyancy bladder inflated be moved across the surface of the water to a pre-selected storage site. One end of the series may be anchored using an attachment which will permit the cage closest the anchor to float while the anchor is secured on the bottom of the water body in which they are to be stored. A boat attached to the other end of the series ~ 21~$39 maintains a small but constant tension on the series maintains their linear orientation. The air is removed from the bladders and the cages sink to the appropriate positions on the bottom of the water body. The inflation hose of the series is plugged and sunk with the cages, after being marked with a surface buoy.
Retrieval of the series of cages simply requires the use of the inflation hose pulled from the bottom by use of a line from the marker buoy and the inflation of the buoyancy bladders once again. The valves installed in the buoyancy bladders permit all bladders to be fully inflated and to exhaust excess air on ascent of the cages to prevent over-inflation and bursting of the bladder.
The submersible cage may also be attached directly to the trap body to accommodate increased volumes of catch in short periods, where the velocity of the river or stream in which the unit iB deployed is not excessive for the increased drag produced by the cage. The flexibility of configuration, interactive features and effectiveness of the harvesting/live holding system is one of its major functional advantages.
Trials of the net for the harvesting of freshwater eels (Anguilla sp) have indicated that the live fish harvesting and holding system of this invention is significantly more effective than traditional methods (collecting up to ten times (10 X~ greater weight of eel than existing designs of eel nets). As the net is designed to harvest downstream migrating eels which would be E ~ s ~; i ~ ~

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permanently lost to river system, the harvest is conducted on a sustainable basis, preventing any depletion of the river stock.
The present invention provides the following novel features:
1. An integrated live harvesting and holding system for migrating or motile fish species which comprises two mechanical components; a highly effective harvesting device and a submersible holding cage which may be used independently or joined in a single unit.
2. Net wings of the harvesting component with appropriate hanging ratios and depths of mesh designed to be shaped by higher velocity water flows to provide a smoothly contoured channel to guide the target species into the trap body section.
3. A novel design of large mesh net or closed fabric apron attached along the bottom of the net wings used to secure the wings to the bottom by ballasting it with available rocks.
4. A novel narrow roof of netting, projecting orthogonally from the vertical wing on either side which, in water depths exceeding that of the net wing, redirects downward the fish attempting to swim over the top of the wing.
5. Novel metallic supports for the net wings which are shaped as a mirror image figure "4" with double angular extensions from an upstream facing vertical pole to enable ~ 21~2~3~

the net wings to remain erect and functioning as a fish barrier in high-velocity water flow conditions.

6. A novel mechanism for facile and rapid attachment and detachment of the top of the wings at the support stakes provides the means whereby the wings may be rapidly dropped from the support stakes.

7. A novel front frame of the harvesting component with a concave curvature which is the same as that for the net wings to which the frame is attached when deformed by the movement of higher velocities of water into the wing netting.

8. Trap body frames with a square outline, preventing movement of the net in turbulence.

9. A novel specially designed rear frame enables rapid detachment and replacement of collection bags during periods of high volume harvesting activity.

10. A novel collection bag with a frame similar to that of the trap body which provides volume space to prevent excessive crowding of the live catch.

11. A novel mechanism for deterring the entry of mammals which may succumb in the net is installed in the circular opening at the apex of the first funnel of the trap body, being a sharp, double-prong which originates from the metallic ring surrounding opening and projects forward into the expanding circumferences of the net funnel.

12. The small mouth at the narrow of the funnel-shaped non-return valve alt the closed end of the trap body 2~ ~2~

may be stretched in tension with the novel use of an elastic material on the slit-like opening for purposes of - preventing the entry of non-target species.

13. A frame constructed of non-corrodible, tubular structural material which does not absorb water and contains adequate air when sealed to provide some buoyancy to the unit.

14. A novel frame design which incorporates a skid or runner which is used to both support the cage frame above the substrate on which it may be dragged and to provide a sled surface for retrieval of the cage from beneath the ice.

15. A hatch or means of access to the cage as afforded by the use of a marine grade zipper of non-corrodible material, in a circular or square shape.

16. A cage being covered by an open fabric such as afibre, plastic or wire mesh, either with or without a variety of protective coatings or partially of an open fabric and partially of a closed fabric such as a vinyl sheeting.

17. A buoyancy lifting bladder for providing buoyancy to the cage comprising a flexible membrane resistant to fluid pressures which is attachable to the cage and of adequate displacement volume so as to lift the cage and its contents when full in fresh water.

18. A novel combination inflow and over-pressure relief valve which permits inflation only up to a marginal value over the ambient water pressure and thereafter shuts ~?~
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off the inflow of air, as well as exhausting excess air upon ascent of the cage.

19. A submersible cage unit which may be attached to others of the same design in series such that a single inflation hose will suffice to provide buoyancy and lift to the whole series of cages.

20. A submersible holding cage which may, in a novel manner, be attached to the body of the harvesting device through means of a standard slot coupling and may be removed from the body trap at will to be replaced by another cage or a net collection bag.

21. A novel method for the join of net panels using a small rope inserted through each mesh on the edges of the net panels to be joined, providing a positive method of joining which ensures greater integrity of the join over that afforded by traditional hand sewing.

22. A novel method of joining the netting of the harvesting device to the trap body frames by the insertion or sewing of a small rope into the meshes of the edge or portion of the netting which are closest to the support frames and the attachment of the small rope to the frame by several means including plastic or wire wrapping material.

23. A novel method of orienting the netting such that hangs in a "square mesh" configuration on the rear frames to reduce "hourglass" narrowing of the body net tunnel between frames caused by the downstream drag on the net body from flowing water.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A fyke net comprising:
a) a trap body tunnel open at one end and including a plurality of inward narrowing funnels;
b) wings or leaders in the panels of vertically hung netting extending from the trap body and adapted to be disposed along the river or lake bottom;
c) wing supports in the form of stakes adapted to be erected into the stream or lake bottom and adapted to maintain the shape and position of the wings and to keep them erect in higher velocity water currents;
and d) a collection bag in the form of an additional closed-end funnel of netting, situated behind the body of the net at the narrow end of the funnels.

2. A holding cage comprising:
a) a containment cage comprising a frame of structural material and a mesh covering;
and b) a flexible bladder attached to the containment cage into an air gas may be injected to provide buoyancy for the containment cage.

3. The combination of:
A) a fyke net comprising:
a) a trap body tunnel open at one end and including a plurality of inward narrowing funnels;
b) wings or leaders in the panels of vertically hung netting extending from the trap body and adapted to be disposed along the river or lake bottom;

c) wing supports in the form of stakes adapted to be erected into the stream or lake bottom and adapted to maintain the shape and position of the wings and to keep them erect in higher velocity water currents;
and d) a collection bag in the form of an additional closed-end funnel of netting, situated behind the body of the net at the narrow end of the funnels; and B) a holding cage comprising:
a) a containment cage comprising a frame of structural material and a mesh covering;
and b) a flexible bladder attached to the containment cage into an air gas may be injected to provide buoyancy for the containment cage.

4. A method for the manufacture of the fyke net of claim 1 comprising the joining of net panels using a small rope inserted through each mesh on the edges of the net panels to be joined, providing a positive method of joining which ensures greater integrity of the union over that afforded by traditional hand sewing.

5. A method for the manufacture of the fyke net of claim 1 comprising joining the netting of the harvesting device to the trap body frames by the insertion or sewing of a small rope into the meshes of the edge or portion of the netting which are closest to the support frames and the attachment of the small rope to the frame by several means including a plastic or wire wrapping material.

6. A method for the manufacture of the fyke net of claim 1 by orienting the netting such that hangs in a "square mesh" configuration on the rear frames to reduce "hourglass" narrowing of the body net tunnel between frames caused by the downstream drag on the net body from flowing water.