In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 130, No. 4_Supplement ( 2011-10-01), p. 2420-2420
Abstract:
As populations become smaller and more endangered, the ability to monitor trends in their abundance also decreases. For vocal species, passive acoustic monitoring can provide a powerful, cost-effective method of monitoring relative abundance. However, the monitoring effort should be based on a statistical design that can detect population declines in time to prevent extinction. This is illustrated with an example of the vaquita (Phocoena sinus) an endangered porpoise in the northern Gulf of California, Mexico. A pilot project showed that porpoise detectors (C-PODs) recorded echo-location clicks from approximately one group of porpoises every two days. Based on this, we estimate that 5000 days of C-POD monitoring per year would be needed to obtain a measure of relative vaquita abundance with a coefficient of variation (CV) of 3%. A power analysis shows that five years of monitoring with this CV would give a high probability of detecting a 5% annual increase or decrease in population size. Visual sighting methods could not detect such small changes with any conceivable level of survey effort. This kind of innovative monitoring is a critical tool in the continuing evaluation of conservation measures.
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
