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1 1.10 Application of estuarine and coastal classifications in marine ...

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improve the design <strong>and</strong> <strong>in</strong>terpretation <strong>of</strong> surveys <strong>and</strong> experimental studies. A <strong>coastal</strong><br />

classification <strong>in</strong> the form <strong>of</strong> a map facilitates sampl<strong>in</strong>g across multiple classes, regardless <strong>of</strong><br />

whether classes are habitat types, socio-economic categories or management strata. One <strong>of</strong> the<br />

greatest benefits <strong>of</strong> us<strong>in</strong>g a consistent classification is that the results from surveys <strong>of</strong> one or<br />

more sites can be directly compared with other studies. A classification can thus be an important<br />

st<strong>and</strong>ard <strong>in</strong> environmental assessment, for <strong>in</strong>stance, where an evaluation <strong>of</strong> the nature<br />

conservation status or long-term monitor<strong>in</strong>g <strong>of</strong> sites is required.<br />

The ma<strong>in</strong> goal <strong>of</strong> sample surveys is to obta<strong>in</strong> accurate, high-precision estimates <strong>of</strong><br />

population <strong>and</strong> community metrics at a m<strong>in</strong>imum <strong>of</strong> cost. Maps <strong>of</strong> environmental covariates,<br />

such as benthic habitat, at the appropriate spatial scales <strong>and</strong> spatial extent can be used to<br />

effectively divide the sampled population <strong>in</strong>to strata. Stratified <strong>and</strong> stratified-r<strong>and</strong>om designs can<br />

use mar<strong>in</strong>e habitat <strong>classifications</strong> to optimize sampl<strong>in</strong>g <strong>and</strong> to target priority areas <strong>and</strong> design<br />

comparative monitor<strong>in</strong>g protocols. A stratified-r<strong>and</strong>om design may divide the survey doma<strong>in</strong><br />

<strong>in</strong>to regions <strong>of</strong> relatively homogenous variance called strata <strong>and</strong> then allocate sampl<strong>in</strong>g more<br />

<strong>in</strong>tensively <strong>in</strong> the highly-variable to achieve better estimates than a simple r<strong>and</strong>om design us<strong>in</strong>g<br />

the same sample size. Better estimates <strong>of</strong> a target variable derived from stratified sampl<strong>in</strong>g can<br />

improve model results considerably when survey data are applied <strong>in</strong> species distribution<br />

model<strong>in</strong>g (Hirzel <strong>and</strong> Guisan 2002).<br />

GIS-based tools for allocat<strong>in</strong>g samples can provide a statistically robust, ecologically<br />

mean<strong>in</strong>gful <strong>and</strong> cost-effective approach to design<strong>in</strong>g a sampl<strong>in</strong>g strategy. For example, NOAA’s<br />

Sampl<strong>in</strong>g Design Tool for ArcGIS (Menza <strong>and</strong> F<strong>in</strong>nen 2007) provides a user-friendly process to<br />

develop sampl<strong>in</strong>g strategies with three ways to generate po<strong>in</strong>t samples: simple r<strong>and</strong>om, stratified<br />

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