Alarming nets: fishermen try acoustics to protect porpoises

Article Abstract:

Commercial fishers in New England hope to prevent porpoises from becoming entangled in their nets by using underwater acoustic alarms. Early studies were inconclusive on the effectiveness of the devices, but research in 1994 suggested that they were effective. However, some scientists are doubtful.

Analysis, Innovations, Equipment and supplies, Protection and preservation, Fishing nets, Fisheries, Porpoises, Fishery technology, Commercial fishing gear

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In the audio spotlight

Article Abstract:

Acoustical engineers have discovered a way of detecting low frequency sound in one direction with the use of special transducer arrays that are smaller across than the wavelength of interest. These parametric arrays make use of subtle nonlinearities in the fluid carrying the sound.

Discovery and exploration, Loudspeakers, Sound

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Tempest on the high sea

Article Abstract:

The Ocean Drilling Program's 470-foot vessel, Resolution, survived a sizable storm in the North Atlantic in 1985. It was protected by 70-foot tall waves that formed after storms from the north and east coalesced.

Research, Natural gas exploration, Oil and gas exploration, Petroleum exploration, United States. National Science Foundation. Ocean Drilling Program

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