Target strength of a nylon monofilament and an acoustically enhanced gillnet: predictions of biosonar detection ranges

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Citation: Mooney, T.A., P.E. Nachtigall, and W.W.L. Au, 2004. Target strength of a nylon monofilament and an acoustically enhanced gillnet: predictions of biosonar detection ranges. Aquatic Mammals, 30(2), ps 220-226.
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Summary:

Metal oxide nets made from barium sulphate increased the detectability of gillnets by marine mammals when compared to nylon nets when approached at angles of incidence greater than normal incidence but less than 40 degrees. Hypothesized detection ranges indicate bottlenose dolphins (Tursiops truncatus) should be able to detect metal oxide nets in time to avoid entanglement, but harbor porpoise (Phocoena phocoena) may not be able to detect either net in time to avoid contact.

Field Studies:
Location Fishing gear Reduction technique Bycatch species Effect on bycatch species Catch Effect on target catch Type
Captivity Gillnets Metal oxide/barium sulfate nets Small Cetaceans (maximum length < 7.5 meters) Increased detectability Trout In the wild