Sequential analysis and design of fixed-precision sampling of Lake Kariba fishes using Taylor's power law

Taylor's power law (TPL), which states that the variance of abundance is a power function of mean abundance, has been used to design sampling of agricultural pests and fish species. We show that TPL holds for means and variances of abundance of accumulated fish samples in the fished and unfished areas separately of Lake Kariba (between Zambia and Zimbabwe), measuring abundance indices by number and weight separately. We use TPL parameters estimated from sequentially accumulated samples to update a stopping line of fixed precision 0.1 after each new sample from a sampling day. Our novel method yields mean abundance estimates similar to those from systematic sampling, and provides a conservative approach to reaching a fixed sampling precision level with reduced sampling labor and time. Mixed-effect modeling showed that fishing increases the slope of TPL. This study provides the conceptual framework and an empirical case study for implementing a sequential sampling method for fish assemblages of an inland la...