In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 130, No. 4_Supplement ( 2011-10-01), p. 2419-2419
Abstract:
In 2008, vaquita population was estimated in only 245 individuals. Between 1997 and 2007, a passive acoustic semi-autonomous system was used for monitoring detection rate of this species. The analysis resulted in decline of approximately 58%. Sighting and acoustic data from a 2008 research cruise, compared to the 1997 estimate of abundance, resulted in a decline of approximately 57%. Hence, passive acoustic detection probed reliable to monitor the population. The Mexican Government implemented a recovery plan, which includes monitoring population trends. At current level, the population can grow at maximum rates lower than 4% annually. The severely reduced population level, and scarcity of acoustic detections, made unreliable to continue the use of the methods applied till 2007. An increase of sampling effort was identified as the key to implement a reliable system, only achievable using completely autonomous detectors. Field test of autonomous detectors identified C-POD as very reliable. Using data collected with this equipment it was determined that an annual effort of 5000 C-POD days is needed to detect population increase. A sampling grid of 62 stations was designed. Work to design and test reliable mooring devices was done. Currently, the first of five years of sampling has started.
Type of Medium:
Online Resource
ISSN:
0001-4966
,
1520-8524
Language:
English
Publisher:
Acoustical Society of America (ASA)
Publication Date:
2011
detail.hit.zdb_id:
1461063-2
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