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 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 device for attracting and/or repelling fish comprises an array of visible light emitting diodes encased in a water resistant, protective housing which is substantially transparent to the visible light emitted by the diodes. In one preferred embodiment, a cylindrical housing containing the diode array is attached to a float, on the upper surface of which is provided a photovoltaic module which charges a battery located in a lower portion of the housing. In other preferred embodiments, the device is adapted to be submerged below the surface of a body of water and is connected to a remote power supply. The device is preferably used to attract fish, with the diodes emitting visible light in the green, blue and violet regions of the visible spectrum.

Abstract: A non-electric perimeter fence to prevent animals from entering a restricted area comprises a vertical barrier member extending to a predetermined height above ground level and an angled barrier member extending upwardly and outwardly from the vertical member relative to the restricted area. The vertical member may comprise a conventional chain link fence and the angled member is preferably made of a sheet material. The surface of the angled member which is presented to an animal attempting to climb over the fence is preferably smooth and free of protrusions which could assist the animal in climbing the fence. Preferably, the height of the angled member is sufficient to prevent an animal such as an adult raccoon from reaching over its upper edge.

Abstract: The invention relates to an automated system for monitoring wildlife auditory data and recording same for subsequent analysis and identification. The system comprises one or more microphones coupled to a recording apparatus for recording wildlife vocalizations in digital format. The resultant recorded data is preprocessed, segmented, and analyzed by means of a neural network to identify the respective species. The system minimizes the need for human intervention and subjective interpretation of the recorded sounds.

Abstract: The invention provides a method of preconditioning selected species of fish to associate characteristic acoustic signals with food, thereby to induce the fish to congregate towards a selected location in response to such acoustic signals.

Abstract: The invention relates to a hydroacoustic sonar system in which received signals are processed without extensive filtering thereby to conserve higher fourier components of the received signals and so conserve useful information of targets. This is achieved by using a wideband detector module to effect demodulation of the received signals, and so eliminating the usual intermediate frequency stage. The module comprises a wideband input amplifier, a wideband full wave detector and an active low pass filter having a cut off frequency of at least 50 kHz.

Abstract: An acoustic device for eliciting either attraction or repulsion behavioral responses in fish comprises a water tight enclosure having a radiating surface rigidly supported in one end thereof. Drive means for the radiating surface are provided with the capability of causing the radiating surface to vibrate at its resonant frequencies so that an acoustic signal is generated capable of a peak sound pressure level of at least 0.5 kPa (0 to peak) at a distance of 3 meters from the radiating surface. The signal generated has one fundamental frequency component in the range 20 to 1000 Hz and a plurality of resonant and harmonic frequencies associated with said fundamental frequency. The drive means, radiating surface and enclosure coact to generate an acoustic signal having characteristics such as resonant frequencies, peak pressures and temporal patterns which may be selectively optimized to produce the desired behavioral response.