Abstract
In ecological studies, the population of interest is often spread over a large area. In these studies, obtaining a sample with good spatial coverage is an important feature in the design of a survey. In most cases adjacent, or neighbouring, units are more similar than units further apart and the resulting spatial autocorrelation should be taken into account.
Two dimensional systematic sampling (grid-based sampling) is one conventional method that has been used in environmental studies to achieve spatial coverage of the area.
Balanced Acceptance Sampling (BAS) is a new method for selecting well spread out sampling units over the study area.
In this paper we will compare the BAS design and two dimensional systematic sampling for selecting samples (quadrats) from a large area, using a case study of a crab species from an intertidal marine zone in Qatar.