2.4.1.2 Census Spatial Design Pros & Cons
The census spatial design describes the location of all the sites comprising the domain of interest. In some cases, a single site might be used to estimate the total number of fish in a population, by the establishment of a counting facility located strategically where all fish will pass and be counted. In other cases, the census might consist of counting fish throughout the population’s domain occupied (or potentially occupied), e.g., at all reaches where the species occurs. In any case, a census implies that all elements will be enumerated. In some cases, it is feasible to conduct a census in a part of the population’s domain, but not all. In these cases, the term “restricted census” applies—part of the population’s domain can be censused; part will be sampled using another type of design.
Tools:
None
Pros and Cons:
The following pros and cons of census-based spatial monitoring designs should assist you in determining if it is appropriate for your monitoring needs.
Site Selection
Pros:
- Covers all sites in the domain or restricted domain, so statistical sampling error is eliminated.
- No assumptions underlie the selection of sites since all sites of interest are sampled.
Cons:
- In most cases a census is not affordable due to the large number of sites in the domain of interest.
Statistical Inference (summary/interpretation of results)
Pros:
- Statistical inference from the census of sites to the target population is unnecessary since the entire target population has been sampled.
Cons:
- When the target population consists of many sites which are all sampled using a census design, it may be necessary to sacrifice careful measurements at each site to save time/money as the expense of increasing measurement variability at each site.
