A vast array of sampling designs can be used to assess the condition of biological populations, but not all designs are equal. The choice of which design to use depends on sampling objectives, cost, expertise, and available data. BioGeo’s Sampling Tool provides a simple way for researchers and park managers to evaluate the costs and benefits of choosing distinct sampling designs within ArcGIS. This approach can also be used quite easily for monitoring in Marine Protected Areas. Two design performance measures are central to comparisons: estimated sample size to achieve a sampling objective and sampling precision (or standard error). From
sample data, the tool allows users to estimate population means and totals, sampling precision, strata means and standard errors, and apply the finite population correction. Samples are areabased and selected from either a user-defined sampling frame or randomly within a user-defined sampling space. Simple random sampling, stratified random sampling, and two-stage sampling
can be performed.
Biogeo’s Sampling Tool was designed for reef fish surveys (Examples:
Flower Garden Banks :
http://ccma.nos.noaa.gov/ecosystems/sanctuaries/fgb_nms.html &
Monitoring Protocols:
http://ccma.nos.noaa.gov/ecosystems/coralreef/fish_protocol.html )
collected by NOAA’s Biogeography Team
( http://ccma.nos.noaa.gov/about/biogeography/welcome.html ). This survey uses a
stratified random sampling design where strata are defined by a benthic
habitat map to efficiently sample reef fish within a National Park.
It is important to note that this tool does not need to be limited to
ecological application for which it was first created. The functions of
this tool are based on well established sampling doctrine and may be
used for any area-based sampling program |
