A precast dam structure includes at least two precast segments coupled together via linkages and a flow path structure. The flow path structure defines a flow path having an intake port and a draft port and is associated with at least one of the at least two precast segments. The flow path structure is configured to provide a change in flow direction, either internally or externally, from the at least one of the at least two precast segments.

A precast dam structure includes at least two precast segments coupled together via linkages and a flow path structure. The flow path structure defines a flow path having an intake port and a draft port and is associated with at least one of the at least two precast segments. The flow path structure is configured to provide a change in flow direction, either internally or externally, from the at least one of the at least two precast segments.

Disclosed in the present invention is a fishway effect evaluation method based on stable isotope method, belonging to the technical field of fishway effect evaluation. The fishway effect evaluation method according to the present invention comprises stable isotope ratio determination, trophic niche estimation and effectiveness evaluation on fishway construction. The evaluation method according to the present invention is used for researching one or more migratory fishes in the upstream and downstream of the water conservancy projects, determining and quantitatively explaining whether the influence of the water conservancy projects on one or more migratory fishes is eliminated or not from the perspective of the ecosystem through comparison and analysis of stable isotopes, and has the characteristics of high detection speed, stable result and the like.

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.

Disclosed is a system and method for transferring fish past a barrier between an upper and lower body of water, including an inlet conduit 11 connecting the upper body to a transfer chamber 13 adjacent the lower body, a delivery conduit 15 connecting the transfer chamber 13 to a level above the surface of the upper body, a valve 12 between the inlet conduit and the transfer chamber, and a gate 14 between the transfer chamber 13 and the lower body. The inlet conduit 11 holds sufficient water so that, once the gate 14 is closed and the valve 12 is opened, fish in the transfer chamber 13 are transported with the water in the transfer chamber through the delivery conduit 15 to an outlet 16.

Aspects of the present disclosure involve hydraulic systems and methods for altering a flow of a body of water, such as a river, channel, and/or other flowing or uncontained bodies of water. In one aspect, a hydraulic system provides a velocity barrier for the impedance of aquatic organism migration. More particularly, the velocity barrier may be adapted based on the swimming capabilities of one or more aquatic organisms to impede migration. The aquatic organism may be one or more species of fish, such as species sea lamprey (Petromyzon marinus). The example implementations shown and described herein reference the restriction of the sea lamprey. However, it will be appreciated that other aquatic organisms could be restricted by the presently disclosed technology, for example, with different hydraulic targets depending on swimming capabilities.

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.

The present disclosure discloses a buffering fishway suitable for emergent flood discharge with reduction in damage and a buffering method thereof. The buffering fishway includes a fishway body, wherein a migration passage is arranged inside the fishway body, one end of which is rotationally connected with a fixing base, and the other end of which is rotationally connected with a counterweighting floating dock, and a plurality of buffering plates capable of swinging are hinged inside the migration passage, furthermore, the present disclosure also provides a buffering method corresponding to it. The present disclosure effectively reduces the potential energy of the flood and weakens the impact force on the fish. Therefore, the gate dam having this design effectively avoids the fish in the fishway from being fiercely impacted by the flood and easily resulting in damage during discharging flood, having a high protective effect on the fish.

An improved sensor fish with robust design and enhanced measurement capabilities. This sensor fish contains sensors for acceleration, rotation, magnetic field intensity, pressure, and temperature. A low-power microcontroller collects data from the sensors and stores up to 5 minutes of data on a non-volatile flash memory. A rechargeable battery supplies power to the sensor fish. A recovery system helps locating sensor fish. The package, when ready for use is nearly neutrally buoyant and thus mimics the behavior of an actual fish.

A system includes a fish stunner configured to stun fish within a stunning zone of a waterway and a conveyor with a portion of the conveyor located below a waterline of the waterway and a second portion of the conveyor located above the waterline such that fish that have been stunned reach the conveyor and are lifted out of the water by the conveyor.