Abstract: A fish pass system includes a helical blade having an outside diameter and an inside diameter extending between a first side of the helical blade and a second side of the helical blade. The inside diameter controls a flow of water flowing in a direction from the first side to the second side, and the inside diameter defines an open center of the fish pass system. Fish traveling in an opposite direction to the direction of the flow of the water pass through the fish pass system by riding in a space between helical blades as the helical blades are rotating, and fish traveling in the direction of the flow of the water pass through the open center of the fish pass system by swimming or moving over the inside diameter of the helical blades.

Abstract: A migratory fish passage arrangement arranges water flow past an obstacle upstream of the water's natural flow direction, and includes a hydraulic flow arrangement with a first intake tube from upstream of the dam from an intake point to a location downstream of the dam to a feeding point, where a fish gate allows fish to enter into an elevation tube, to enter from the feeding point in the water in the elevation tube to be transported in the elevation tube to an outlet upstream of the dam. The intake point is higher than the outlet. Also disclosed is a system to guide a migratory fish to pass a dam that includes the migratory fish passage arrangement and additionally a siphon tube from an upstream location with respect to the dam to a downstream location with respect to the dam to constitute a migratory fish return route.

Abstract: A fish ladder includes a channel with first and second sidewalls spaced apart at a channel width distance. Each of a first plurality of side-baffles is attached to the first sidewall and each of a second plurality of side-baffles is attached to the second sidewall. Each side-baffle extends a predetermined distance into the channel. A first slot opening width distance from a tip of each one of the first plurality of side-baffles across the channel and perpendicular to the second sidewall substantially equals a second slot opening width distance from a tip of each one of the second plurality of side-baffles across the channel and perpendicular to the first sidewall. A side-baffle spacing distance from a tip of each one of the first plurality of side-baffles and perpendicular to a corresponding one of the second plurality of side-baffles located upstream substantially equals the first and second slot opening width distances.

Abstract: Provided is an aquaculture system, including a water tank holding seawater and housing shellfish or fish to be cultivated, a water intake unit for introducing the seawater into the water tank, a draining unit for draining the seawater in the water tank, a first bubble generator that generates and supplies microbubbles with a diameter of not less than 10 ?m and not more than 100 ?m in the water tank, and a second bubble generator that generates and supplies nanobubbles with a diameter of not more than 10 ?m in the water tank, wherein the seawater in the water tank is exchanged by simultaneously carrying out introduction of the seawater using the water intake unit and drainage of the seawater in the water tank using the draining unit.

Abstract: A system of harvesting sea creatures from a trench holding the sea creatures in seawater, including a trench, an injection well, and a harvesting apparatus that extracts the sea creatures from the trench. The trench includes a gate at one end of the trench. The gate insertable into an opening at the end of the trench to prevent seawater from entering or exiting the trench and removable from the opening to allow the seawater to enter or exit the trench. The injection well is positioned external to the trench and can receive the seawater discharged from the trench. The harvesting apparatus includes a conveyor that inclines. The conveyor includes a conveyor belt and a wedge at one end of the conveyor that contacts the bottom floor of the trench when the conveyor is inclined.

Abstract: Migrating fish often want to travel between different bodies of water, which may be positioned at different heights. To overcome these heights, water passages may be used that provide a water path at a slope over which a fish is able to swim up. A compact housing is provided by allowing a water guide over which the water flow flows to rotate around an axis parallel to gravity in a helical shape. The fish lock may be provided with a resting chamber which comprises a volume of water with a low flow velocity. Sensors and a controller may be provided to control a flow rate of the water through the fish lock according to for example the type of fish passing through the fish lock and an administrator may monitor the fish lock at a distance and may be contacted in case of malfunction.

Abstract: A method for controlling the gate based on the habitat requirement for fish overwintering in rivers. According to the characteristics of biological habitat of the river and the habitat demand of fishes during overwintering, the method specifically comprises the steps of: firstly, determining candidate fishes for ecological flow calculation though fish resources investigating and historical data, and then screening out the target fish by adopting hierarchical analysis method; Secondly, establishing a quantitative response relationship curve between target fish physiological adaptions and water temperature, obtaining ecological water level which ensures the target fish overwintering safely according to the vertical temperature distribution, and establishing the relation between water depth and discharge using hydrodynamic model; finally, setting up a gate control system including a radar water level meter in the overwintering areas and an ecological water level management system in a gate control room.

Abstract: An energy generating unit for generating electric energy from water power is provided. At least one turbine system is installed in a conventional standard container in a channel which rungs in the standard container. The channel is arranged in the flow direction of a surrounding body of water. A fishway is provided on or in the standard container.

Abstract: A hydraulic structure having walls (1) creating a downstream narrowing passage in a streaming surface water. The downstream ends (4) of the walls (1) are edged in order to generate vortices (2) dissolving from the edges (4) downstream which dissipate the energy of the flow created by a level difference between the entry and the exit of the passage.

Abstract: Debris adhering to the outer surface of a barrel-type fish screen is cleared by air bursts from a series of perforated air pipes positioned inside the outer foraminous shell of the screen, the perforations being holes with axes at an acute angle to the screen radius for efficient use of the air. Separately, the conical water collection manifold mounted inside the shell is open at its narrow end, with a valve mounted to that open end to control the opening. The opening prevents reduced water inflow at that end of the manifold, and the valve adjusts the access of the surrounding water to the opening, thereby allowing the manifold to be tuned to more closely approach a uniform distribution of axial water flow along the length of the collection manifold for different ambient conditions.

Abstract: The system and methods of the present invention selectively permit aquatic organisms to bypass an obstruction, such as a lock or a dam. Certain embodiments of the system include a container through which aquatic organisms and water may flow, a container pressurizer for pressurizing the container, and a pressure control mechanism.

Abstract: A device to provide a bypass for fish from an upstream reservoir behind a dam, to a lower elevation downstream reservoir. The device employs a flow separation apparatus for separating aquatic life entering the device and communicated to the downstream reservoir, from a portion of fluid flow communicated to the dam intake. The moving fluid within the device creates turbulence to provide a cushioning effect to protect the fish from impacts, while directing water streams to urge fish to an upper portion of the device distant from the water being communicated to the dam in the lower portion.

Abstract: A safe fish guide path structure includes a horizontal tube having an intake and exhaust valve for controlling levels of air having lower viscosity than water. The horizontal tube is equipped with a transparent window at both sides about the intake and exhaust valve. The horizontal tube is installed at a weir or a bank. An inclined tube extends horizontally from both sides of the horizontal tube. An extended tube extends horizontally from an end portion of the inclined tube. An inlet tube extends from an end portion of the extended tube toward an upper side, while communicating with the extended tube, with water flowing through the inlet tube. A cover has an insertion groove at one side into which the extended tube is inserted, and a cut-away groove at the other side for water to flow through the cutaway groove.

Abstract: A liner for repairing a culvert includes a substantially semi-cylindrical body having an inside surface and an outside surface. The liner is configured for attachment to an inside surface of a culvert and has a shape corresponding to the inside surface of the culvert.

Abstract: One embodiment of a fish guidance and exclusion barrier having an upper reticulated section (10) imbricated by a lower reticulated section (12) which communicates with the upper section. The upper and lower sections are attached in an above water position to a floating device (24) with the lower section being suspended from the floating device utilizing funicular leads (22). The funicular leads are affixed to the floating device with latch type connectors (20) attached to loop type mounts (18) and to the lower sections with latch type connectors attached through grommets (16). Other embodiments are described and shown.

Abstract: An improved fish passage apparatus is combined with hydroelectric power generation to facilitate migration of fish between water bodies of different heights with minimal injury or trauma to fish. It may also be optimized for power generation when fish are not moving through it. The fish passage apparatus comprises parallel connecting tubes providing fluid communication between upper and lower water bodies, upper valves in each connecting tube adapted to control flow of water to or from an upper water body, lower valves in each connecting tube adapted to control flow of water to or from a lower water body, and working tubes opening into each connecting tube between the upper and lower valves a working portion of which extends functionally vertical to above a water level of the upper body of water and to below a water level of the lower body and is vented at its top such that water can flow freely in and out of the working portion.

Abstract: An improved fish passage apparatus is combined with hydroelectric power generation to facilitate migration of fish between water bodies of different heights with minimal injury or trauma to fish. It may also be optimized for power generation when fish are not moving through it. The fish passage apparatus comprises a connecting tube providing fluid communication between upper and lower water bodies, an upper valve in the connecting tube adapted to control flow of water to or from an upper water body, a lower valve in the connecting tube adapted to control flow of water to or from a lower water body, and a working tube opening into the connecting tube between the upper and lower valves a working portion of which extends functionally vertical to above a water level of the upper body of water and to below a water level of the lower body and is vented at its top such that water can flow freely in and out of the working portion.

Abstract: An improved fish passage apparatus is combined with hydroelectric power generation to facilitate migration of fish between water bodies of different heights with minimal injury or trauma to fish. It may also be optimized for power generation when fish are not moving through it. The fish passage apparatus comprises a variable inlet connected to a connecting tube providing fluid communication between upper and lower water bodies, an upper valve in the connecting tube adapted to control flow of water to or from an upper water body, a lower valve in the connecting tube adapted to control flow of water to or from a lower water body, and a working tube opening into the connecting tube between the upper and lower valves a working portion of which extends functionally vertical to above a water level of the upper body of water and to below a water level of the lower body and is vented at its top such that water can flow freely in and out of the working portion.

Abstract: An improved fish passage apparatus is combined with hydroelectric power generation to facilitate migration of fish between water bodies of different heights with minimal injury or trauma to fish. It may also be optimized for power generation when fish are not moving through it. The fish passage apparatus comprises a connecting tube providing fluid communication between upper and lower water bodies, an upper valve in the connecting tube adapted to control flow of water to or from an upper water body, a lower valve in the connecting tube adapted to control flow of water to or from a lower water body, and a working tube opening into the connecting tube between the upper and lower valves a working portion of which extends functionally vertical to above a water level of the upper body of water and to below a water level of the lower body and is vented at its top such that water can flow freely in and out of the working portion.

Abstract: A dam bypass apparatus including a floating inlet and a flexible conduit having a discharge opening adjacent to a dam water intake. The inlet can be laterally offset from the discharge opening, and can include screens to exclude debris from the conduit.

Abstract: A water diversion system includes a hydraulic chute and a chute screen assembly in the hydraulic chute having a wedge wire screen. The water diversion system also includes at least one collection chamber located below the screen configured to collect filtered diversion water which has passed through the screen. The hydraulic chute includes a base, a crest, a sloped accelerator, and an abrupt drop with an adjustable lip, which forms a hydraulic formation in a downstream pool. The hydraulic chute can also include sloped sidewalls, which constrict the flow of water and form fish passage zones. In addition, the chute screen assembly can include a modular panel configured to facilitate construction, maintenance and replacement of the wedge wire screen.

Abstract: A fish pass comprises material (1) that augments a significant part of the crest of a water penning control structure (11) and a channel component (3) to convey water downstream of the water penning control structure (11), the channel component (3) having a hinged attachment to the crest of the water penning control structure (11).

Abstract: A fish passage system is provided that includes a first weir and a second weir upstream of the first weir. The first and second weirs are each moveable between a deflated condition and an inflated condition. The fish passage system further includes a controller to move the first and second weirs between the inflated and deflated conditions to create at least one pool between the first and second weirs so that fish can migrate upstream and/or downstream of the system without having to jump the first and second weirs.

Abstract: Fishways of turbine structures and gate structures for environmentally-friendly tidal power plant through which fish can pass through are provided. The fishway comprises of sea side fishways and lake side fishways to allow fish to move between the sea side and the lake side by forming inside stuffing space filled with seawater for shorter construction period and concrete reduced placing quantity in a certain section of the vertical middle walls installed on the base of which the bottom part is on the marine rock to form blocks of turbine structures and gate structures in a tidal power plant, and seawater on the sea side and the lake side is flown through the front and rear of such inside stuffing space.

Abstract: A fish-safe screened water diversion apparatus having an input and diverted and non-diverted outputs. Water or other fluid is directed substantially downward under the screen at the input and preferably flows under the screen in a substantially unimpeded manner to the non-diverted output or substantially upwardly and/or diagonally through the screen to the diverted output. Various diversion apparatus and screen embodiments are disclosed.

Abstract: Structure and method for safe downstream passage of juvenile fish of any species around hydroelectric dam projects using a combination of deeply submerged extended turbine intakes and surface-oriented bypass flows near the dam structure. The turbine intakes are extended upstream from the dam face.

Abstract: An apparatus or biopassage (A) includes a housing (20) dimensioned for receipt in a waterway during an increased flow event. The housing has a passage: (26) that provides a region of reduced flow generally irrespective of the flow external to the passage. A flow disrupter (50) disturbs laminar flow in the waterway above the passage. A preferred embodiment of the disrupter includes surfaces (52, 54) disposed in angled relation relative to a common apex (60) located above a longitudinal opening (30passage. The surfaces include a series of peaks and valleys formed by angled planar portions (56) in one arrangement. A deflector (NC) is positioned upstream of an inlet end (40) of the passage to direct water away from the passage.

Abstract: A muted tidal regulator adapted to be interposed between a tidal body of water and an inland area at least partially isolated from the tidal body of water by a physical barrier. The assembly includes a tide gate that is made up of a conduit connecting said tidal body of water to said inland area and a closure operable to selectively prevent water flow through the conduit. The assembly also includes an inland water level sensing device and a closure control assembly responsive to the sensing device and adapted to affirmatively permit water flow through the conduit when the sensing device senses an inland water level below a threshold.

Abstract: An apparatus for separating animated objects such as fish or other objects between a non-diverted and diverted fluid stream. Embodiments may include a screen or similar selective pass through device that is arranged in a manner that is generally horizontal (more horizontal than vertical). The non-diverted flow preferably passes over the screen while the diverted flow passes through the screen. Aspects of the apparatus may include faster sweeping velocity than pass through velocity, tapered side or bottom walls, a depressed low flow channel, a distributed under screen reservoir that facilitates distributed fluid flow through the screen or like devices, amongst other aspects.

Abstract: A structure for diverting fish away from water intakes comprises a porous dike having a bottom portion, a central portion, and a top portion, the top portion preferably being submerged a short distance below the surface, and the central portion having flow passages. In a preferred embodiment, the top and bottom portions comprise solid blocks and the flow passages in the central portion are lined with zebra mussel resistant sleeves to minimize clogging. Preferably the sleeve can be readily replaced as desired.

Abstract: A bypass channel (C) for fish extends along line one side of a river, for the full length of a section of the river in which reservoirs (22, 24, 26, 28) have been created by dams (14, 16, 18, 20). The channel (C) follows the grade of the natural river. It includes an inner wall (34) that varies in height so that it is always higher than the water level in any of the reservoirs. It also includes an outer wall (36) and a bottom wall (38) which are formed on the natural terrain that borders the river and reservoirs. In at least its taller regions, the inner wall (38) may be braced by a diagonal member or a system of member (40). Water flow into the channel (C) maybe regulated by horizontal and/or vertical gates (50, 52) or some other structure for changing the cross sectional area of the channel (C).

Abstract: A fish ladder for incorporation between ends of a water structure that includes at least a pair of separate sleeves that are each formed from a puncture resistant flexible material, contain a volume of water and may have a closed end or ends for resting on edge portions of a flat base plate of the fish ladder. The flat base plate includes a pair of parallel spaced apart upstanding side walls that are individually extend across the flat base plate. The upstanding side walls each include pairs of spaced apart channels extending from the side walls, with the pairs align to receive flat rectangular dam sections fitted therein, forming interior dams that a flow of water, as travels through the fish ladder, fills between as pools that fish, traveling up stream, jump between, to travel up the fish ladder and exit into a body of water that is contained by the water structure.

Abstract: A fish ladder for incorporation between ends of a water structure that includes at least a pair of separate sleeves that are each formed from a puncture resistant flexible material, contain a volume of water and may have a closed end or ends for resting on edge portions of a flat base plate of the fish ladder. The flat base plate includes a pair of parallel spaced apart upstanding side walls that are individually extend across the flat base plate. The upstanding side walls each include pairs of spaced apart channels extending from the side walls, with the pairs align to receive flat rectangular dam sections fitted therein, forming interior dams that a flow of water, as travels through the fish ladder, fills between as pools that fish, traveling up stream, jump between, to travel up the fish ladder and exit into a body of water that is contained by the water structure.

Abstract: A system and method for guiding fish that migrate is provided. A preferred embodiment is affixed to a dam having intakes that: a) generate hydroelectric power and b) serve as a natural hydraulic cue for fish that, once attracted to the intake, may be injured or killed traversing the intake. A device resembling an oversize kitchen exhaust fan hood, with extension, is affixed adjacent the upstream side of a stream barrier that otherwise precludes fish from safely passing. The device simulates a naturally occurring hydraulic cue that fish use to migrate and may be used to defeat competing detrimental hydraulic cues. Also provided are embodiments to enable adjustment of the device to meet changing hydraulic conditions; to preclude the accidental provision of competing negative cues or stimuli; and to complement the simulated natural hydraulic cue provided by the device through using stimuli such as light, sound or combinations thereof.

Abstract: A bypass channel (C) for fish extends along line one side of a river, for the full length of a section of the river in which reservoirs (22, 24, 26, 28) have been created by dams (14, 16, 18, 20). The channel (C) follows the grade of the natural river. It includes an inner wall (34) that varies in height so that it is always higher than the water level in any of the reservoirs. It also includes an outer wall (36) and a bottom wall (38) which are formed on the natural terrain that borders the river and reservoirs. In at least its taller regions, the inner wall (38) may be braced by a diagonal member or a system of member (40). Water flow into the channel (C) maybe regulated by horizontal and/or vertical gates (50, 52) or some other structure for changing the cross sectional area of the channel (C).

Abstract: A fish test circuit for the evaluation of waterway barrier bypass systems with a conduit having at least one bypass system test station, water flow within the conduit, fish introduced into the conduit, and measurement of the effectiveness of the bypass system under test. In the preferred embodiment of this invention, the measurement of the effectiveness of the bypass system under test includes determining the survival or mortality rate of the fish as they pass through each bypass system undergoing test. The test circuit may be a closed loop or a side channel of another waterway. An important benefit and feature of this invention is the capability to evaluate multiple and differing bypass systems under similar water flow, water conditions and water quality conditions.

Abstract: A method for enhancing or generating a water flow current by the generation of a velocity head differential, to guide fish, including: a venturi eductor to induce higher water pressures; a pump, piping or other motive water source; an adjustable frame to mount the venturi eductor; and a method of using this equipment. Fish may be guided into or away from a waterway area by generating or enhancing a current to guide them. The apparatus may be used as a method to guide fish through low velocity areas of a river, lake, reservoir or other waterway. The apparatus may also be used as a method to create water flow velocities that fish are reluctant to pass through for a barrier or curtain to further guide the fish. The apparatus and method may also be used to transfer temperature-variant water in a waterway.

Abstract: Provided are a device and associated method for simulating natural hydraulic cues received instinctively by waterborne fauna. A preferred embodiment is suitable for modifying existing manmade barriers such as fish diversion screens used at dams. The simulated cues mimic those produced by the flow of water over rough streambeds. Fish detect the cues and avoid contact with the barriers in the same way that they avoid collision with natural features. In one embodiment, a series of rectangular plates are attached to the U-clip connectors on the downstream side of diversion screens. The plates are oriented approximately perpendicular to the flow lines approaching the surface of the screen. The flow contacts the plates and, because the orientation of the plate creates an unstable hydraulic field, the flow alternately slips above and below the plates, creating fluctuating local acceleration zones able to be detected by migrating fish and other waterborne fauna.

Abstract: The present invention is a safe and effective fish ladder for assisting fish in overcoming dams, especially in the upstream direction. The ladder comprises a series of relatively vertical open pools, which decrease in size in the upstream direction, the pools being conveniently spaced apart a vertical distance which may be easily jumped by the particular fish species of interest. By being arranged relatively vertically, so that the downstream perimeter of one pool is substantially within the downstream perimeter of the pool directly beneath the one pool, the fish ladder does not need to be long and expensive if the dam to overcome is high. Also, by being relatively vertical, the ladder may be conveniently built onto already existing vertical components on the downstream side of a dam, for example, onto the support structure for the discharge flume for downstream migrating fish in the apparatus disclosed in U.S. Pat. No. 5,161,913 (Boylan).

Abstract: An apparatus for generating a current to guide fish includes a propeller; a device to rotate the propeller; and a frame to mount the propeller and the device to rotate the propeller. Fish may be guided from an intake area to a fish bypass by generating a current leading away from the intake area. The apparatus may also be used to guide fish through low velocity areas in river situations.

Abstract: The present invention is a safe and effective fish ladder for assisting fish in overcoming dams, especially in the upstream direction. The ladder comprises a series of relatively vertical open pools, which decrease in size in the upstream direction, the pools being conveniently spaced apart a vertical distance which may be easily jumped by the particular fish species of interest. By being arranged relatively vertically, so that the downstream perimeter of one pool is substantially within the downstream perimeter of the pool directly beneath the one pool, the fish ladder does not need to be long and expensive if the dam to overcome is high. Also, by being relatively vertical, the ladder may be conveniently built onto already existing vertical components on the downstream side of a dam, for example, onto the support structure for the discharge flume for downstream migrating fish in the apparatus disclosed in U.S. Pat. No. 5,161,913 (Boylan).

Abstract: A barrel type fish and/or particulate screen includes mesh stretched over a supporting cylindrical shell having closed ends. The closed interior opens to a fluid withdrawal conduit, which is connected to an outlet. An inner, substantially conical withdrawal manifold is provided with the base of the substantially conical withdrawal manifold connected to the withdrawal conduit and the manifold extending substantially the axial length of the cylindrical mesh. The substantially conical withdrawal manifold defines uniformly sized and arrayed flow apertures. These flow apertures have the same unit area per unit length of the substantially conical withdrawal conduit. This same unit area per unit length produces within the withdrawal manifold, a substantially constant velocity at all cross-sections of the manifold taken normal the flow along the major axis of the substantially conical shape. Flow velocity distribution through the metal mesh is maintained uniform at all rates of flow through the device.

Abstract: This invention of a fish test circuit for the evaluation of waterway barrier bypass systems is a conduit having at least one bypass system test station, a means for providing water flow within the conduit, a means for introducing fish into the conduit, and a means for measuring the effectiveness of the bypass system(s) under test. In the preferred embodiment of this invention, the means for measuring the effectiveness of the bypass system(s) under test includes a means for determining the survival or mortality rate of the fish as they pass through each bypass system undergoing test. The test circuit may be a closed loop or a side channel of another waterway. An important feature and benefit of this invention is the capability to evaluate multiple and differing bypass systems under similar water flow, water condition and water quality conditions.

Abstract: A fish-safe screened water diversion apparatus having an input and diverted and non-diverted outputs. Water or other fluid is directed substantially downward under the screen at the input and preferably flows under the screen in a substantially unimpeded manner to the non-diverted output or substantially upwardly and/or diagonally through the screen to the diverted output. Various diversion apparatus and screen embodiments are disclosed.

Abstract: A method and system allowing fish to migrate upstream and downstream, bypassing dams, obstructions, either man-made or natural, safely, freely and in a natural manner. The system consists of a meandering “nature-like” channel constructed of pneumatically placed concrete, shotcrete or gunite that simulates a waterway bed condition. The construction of riffles, ledges, undercut banks and other natural-like features to provide a foundation for the placement of fish habitat, such as gravel beds, boulders, logs, and the like. The placement of sand, gravel, cobbles and such to create and provide an aquatic environment to sustain plant and aquatic life. The introduction of plants and other aquatic life to provide forage, cover and a year around natural-like environment within a river or stream-like migratory bypass channel.

Abstract: An apparatus for separating animated objects such as fish or other objects between a non-diverted and diverted fluid stream. Embodiments may include a screen or similar selective pass through device that is arranged in a manner that is generally horizontal (more horizontal than vertical). The non-diverted flow preferably passes over the screen while the diverted flow passes through the screen. Aspects of the apparatus may include faster sweeping velocity than pass through velocity, tapered side or bottom walls, a depressed low flow channel, a distributed under screen reservoir that facilitates distributed fluid flow through the screen or like devices, amongst other aspects.

Abstract: A fish ladder is used at a water way outlet of a water way which is higher than a body of water. The fish ladder reduces jump heights for fish entering the water way outlet from the body of water. The fish ladder is a series of tiers installed below and up to the water way outlet, thereby reducing the jump height between the water way outlet and the body of water. The fish ladder is a modular design which can be altered to fit the needs of a particular site based on the size of the body of water, jump height and water way outlet size. The height, length and width of the tiers, as well as the number of tiers, is specific to the site of the installation.

Abstract: A system and method for guiding fish that migrate is provided. A preferred embodiment is affixed to a dam having intakes that: a) generate hydroelectric power and b) serve as a natural hydraulic cue for fish that, once attracted to the intake, are converted to pet food. A device resembling an oversize kitchen exhaust fan hood, with extension, is affixed adjacent the upstream side of a stream barrier that otherwise precludes fish from safely passing. The device simulates a naturally occurring hydraulic cue that fish use to migrate and may be used to defeat competing detrimental hydraulic cues. Also provided are embodiments to enable adjustment of the device to meet changing hydraulic conditions; to preclude the accidental provision of competing negative cues or stimuli; and to complement the simulated natural hydraulic cue provided by the device through using stimuli such as light, sound or combinations thereof.

Abstract: A fishway is disclosed for providing a pathway around obstacles for fish. The fishway is comprised of a pair of spaced fishway walls and a set of weirs located between the fishway walls for dissipating flow energy of water flowing through the fishway. The weirs are disposed in longitudinally spaced relation along the fishway and each consecutive pair of weirs defines a pool between the pair. The weirs are comprised of a center wall, first and second middle walls attached to the center wall on opposite sides of the center wall, and first and second outer walls which are attached at one edge to the first and second middle walls respectively and at the opposite edge to a respective one of the fishway walls. The first and second middle walls form an acute angle facing away from the flow of the water, and each attached middle and outer wall, respectively, form an angle facing towards the flow of the water which is less than 180°.

Abstract: Currently migratory fisheries are impeded in their upstream and downstream movements by one or more dams across rivers. A method and structure is described that overcomes the shortcomings of currently employed methods such as fish ladders, water spilling and barging. A channel of sufficient dimensions to simulate a natural stream bed is employed to parallel the entire length of river and reservoirs and provide passage for the fish. This is accomplished without the breaching and destruction of the dams bypassed.