The NetMark 1000 by the Dukane Corporation, used to safeguard porpoises from net entanglement, employs technology developed in the late 1960s by NASA engineers at the Langley Research Center. It is based on an underwater location aid, able to withstand high impact, then emit multidirectional signals for hours on end, originally used in the retrieval of NASA payloads following watery touch-downs on Earth. Dukane and Burnett Electronics later obtained a license from NASA, further improving on the beacon design. In a large scale experiment off the coast of New Hampshire in autumn of 1994, it was found that the use of acoustic alarms appears to hold considerable promise in reducing the number of harbor porpoises killed in the sink gill nets in the Gulf of Maine. Dukane has sold well over 100,000 units. Applications of the pinger are also expanding to other animal species.
Safeguarding Porpoises
1997-01-01
Sonstige
Keine Angabe
Englisch
NTIS | 1997
Acoustic signals by Harbour porpoises (Phocoena phocoena)
British Library Conference Proceedings | 1995
|Online Contents | 1994