power analysis

Using Changes in Naive Occupancy to Detect Population Declines in Aquatic Species; Case Study: Stability of Greenhead Shiner in North Carolina

SEAFWA Journal Volume 3, March 2016

Determining population trends for many aquatic species is problematic for most resource agencies because little or no historical information is available on population size nor are resources available for contemporary population estimates. Managers often only have available to them presenceabsence data collected by qualitative surveys conducted at intermittent intervals. Changes in naïve occupancy can be used to detect population trends. Naïve occupancy is the ratio of number of sites where a species is detected to total number of sites surveyed, without correcting for imperfect detection...


Increasing the Efficiency of Florida&#39s Freshwater Fisheries Long&#45term Monitoring Program

SEAFWA Journal Volume 1, March 2014

In an effort to evaluate the Florida Fish and Wildlife Conservation Commission (FWC)'s long-term fisheries monitoring program for inland water bodies, we conducted a power analysis utilizing fish data from electrofishing, mini-fyke net, and gill net samples. We resampled data and simulated the effects of different combinations of gear and sample size for collecting presence - absence information. Our objective was to determine whether the use of either mini-fyke nets or gill nets could be eliminated or reduced in the monitoring program. Thirty fyke net/gill net gear combinations were...