Abstract: A lock-type fishway comprises a first part having an opening to lower water for discharging water therethrough to lure fishes to the first part and a second part having an opening to upper water. A first pipe between the first and second parts is to be filled with water by closing a gate at the first part for bringing the fishes gathered in the first part to the second part. A second pipe is in parallel to the fishway between the upper water and first part and is provided with a turbine for conducting the luring water therethrough and for recovering energy from the luring water.

Abstract: Method and apparatus for fish migration past dams and other water barriers. A preferred embodiment 100 comprises a conduit 101 passing from downstream side 22 of water barrier 10 to upstream side 21 of the barrier, flow-controlling valves 102 and 105 disposed in series within conduit 101, and actuators 103 for opening valves 102 and 105 in the presence of fish. Fish 30 are attracted by flow 130 passing through conduit 101 at controlled rates by means of flow-through devices in valves 102 and 105. On entering forechamber 104 and swimming upstream the fish pass actuators 103, which cause first valve 102 to open. As first valve 102 opens, water flow through conduit 101 remains controlled and substantially uniformly turbulent under action of second valve 105. With valve 102 open fish 30 may swim to mid-span section 140 of the conduit. When no further fish are present in forechamber 104 or passing actuators 103, or enough fish are present in section 140, the first valve closes.

Abstract: The invention relates to a fish ladder (1) to by-pass a vertical descent (SH) in a flowing watercourse (31F) or a dam (31T), with an upstream water inlet (2) and a downstream water outlet (3) and with basins (4) arranged between them substantially in the downstream direction, each of which has an inflow slot (5Z) and an outflow slot (5A) as vertical through-flow slots (5) and deviating apparatus (6, 13) to form a meandering passage. The basins (4) have a partially cylindrical inner wall (40). Successive basins (4a, 4b, 4c, 4d) are arranged against one another and mutually laterally offset in such a way that the through-flow slots (5) run transversely to the direction of slope (G). The through-flow slots (5) are bounded on both sides by a first vertical partially cylindrical pipe (60) over the entire height (H) of the basin as a first diversion (6) with a substantially smaller radius in relation to that of the inner wall (40) of the basin.

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: An automated biomonitoring system for monitoring water quality includes an exposure chamber for housing an aquatic organism having ventilatory behavior and body movement sensitive to water quality. Electrodes sense electrical signals produced by the organism during its ventilatory behavior and body movement, and a controller responsive to signals from the electrodes determines a plurality of ventilatory parameters based on the signals. The ventilatory parameters are compared with corresponding thresholds to determine when the water to which the organism is exposed has caused physiological stress to the organism.

Abstract: A system for controlling a hydroelectric power production facility includes sensors for detecting the presence of fish adjacent to the facility. A controller linked to the sensors controls the orientation of control surfaces associated with a turbine/generator set to enhance the survivability of fish entrained into the facility when fish are detected to be present. The system may be adapted to control fish bypass and spillway structures within the facility to further enhance the survivability of fish populations. The system balances fish survivability with other parameters related to the operation of the facility, optimizing power production levels once estimates of fish survivability meet targets or optimum levels. The system may be adapted to coordinate control of several facilities along a water system to permit implementation of an overall water, fish and power management plan.

Abstract: A mobile system for directing fish away from danger points at an underwater structure includes multiple submersible flash heads operatively connected to a power and control center installed inside a trailer. The flash sequence, rate and intensity are adjustable by the system operator in real time using a system control unit which can be remotely controlled. The flash heads, connected in a tri-pack configuration, are strobed in a manner intended to alter the behavior of the fish. The system may include means to generate an air curtain near the flash heads to improve light dispersion and water jet means to clean the lenses on the flash heads.

Abstract: A system for directing fish away from danger points at an underwater structure includes multiple submersible flash heads operatively connected to a flash head control unit. The flash sequence, rate and intensity are adjustable by the system operator in real time using a system control unit which can be remotely located. The flash heads are strobed in a manner intended to alter the behavior of the fish. The system may include means to generate an air curtain near the flash heads to improve light dispersion and water jet means to clean the lenses on the flash heads.

Abstract: An apparatus and method for continuously cleaning fish screens located in wetland diversions which are subject to tidal fluctuations, as well as in river and stream diversions, provides a brush or wiper member attached to a flotation device to clean the fish screen continuously. The apparatus can utilize conventional power where available, or utilize available and renewable energy sources such as tidal influx, solar or wind power, as well as gravity water flow.

Abstract: An improved fish deterrent and guide utilizing generally a pneumatic oscillator (1) and oscillated plate (9), to generate water particle motion (low frequency sound or infrasound) and specifically water particle accelerations to which fish exhibit an avoidance response. The invention is reliable, reasonably portable and deployable, low-maintenance, and tunable to produce the desired water particle motion. Reliability is due to the piston (4) being cushioned by air at the end of each stroke and redirected without impacting the casing. The operation of the apparatus is easily verified from the water surface by inspection of the backpressure regulator (13). The apparatus is tunable through adjustment of the inlet pressure, backpressure, and size, shape, and mass of the oscillated plate.

Abstract: Migrating anadromous fish, and particularly salmonoid smolts, are guided in or by elongate faster moving channels defined in a body of slower moving water. Ring-like support frames are supported by floats and anchors in a water body at spaced distances along a faster moving channel to be defined. Each support frame carries one or more nozzles that receive pressurized water from a water supply system and disperse that water toward the next spacedly adjacent downstream support frame to define the faster moving channels without use of physical peripheral boundary members. The water supply system may be associated with individual support frames or with a plurality of support frames to receive water from the body in which the faster moving channel is defined and pressurize that water for dispersement. Fish are introduced into the upstream portion of the faster moving channel and instinctively tend to remain within the channel so long as the faster water motion exists therein.

Abstract: The gradient salt concentration fishway is installed on or near the river bank, at points contiguous to existing flood control dams and weirs. Fresh water flows naturally downstream via the fish way. Salt water is pumped from the sea into several points in the fish way in order to mix with the fresh water of the river. By controlling the amount of salt water introduced at each stage of the fishway, the concentration of salt within the entire fishway can be made gradient. Hence, the concentration of salt nearest the ocean is the greatest while it decreases the closer it gets to the fresh water. Above the dam, the fresh water is not mixed with salt water. This system will more accurately approximate the natural conditions encountered by fish entering a brackish environment, thus easing the biological adjustments which migrating fish need.

Abstract: The invention relates to a method for preventing fish-borne parasites from spreading to a watercourse (1) or a limited area (4) of a watercourse (1) without such parasites. According to the invention, all the fish to pass into the area (4) are forced to go through a bath of water containing an active substance which kills or removes from the fish the parasite or parasites which should be prevented from spreading, without killing or seriously injuring the fish. The invention also relates to a plant for carrying out the method.