Conducting sample size analysis is important to ensure that sample sizes are adequate to meet objectives for precision but not so large that valuable resources are wasted. When simple survey designs are used, sample size analysis is straightforward. However, creel surveys often follow complex designs that can make sample size estimation difficult. The objectives of this study were to provide sample size estimators for commonly used creel survey designs and investigate sample size requirements to achieve varying levels of precision. For estimates of angling effort, the average sample size among fisheries….Read more

Discarded catch can account for a significant amount of fishing mortality and can be a major source of uncertainty when calculating total removals for stock assessments and management. Observers provide estimates on the types and quantity of fish that are caught, but observer coverage of a fleet can often vary directly with funding. On the Northeast U.S. shelf, the Northeast Fisheries Observer Program (NEFOP) has collected data on catch and discards for assessment and management purposes since 1989. The Cooperative Research Study Fleet (hereafter “Study Fleet”), working with the Northeast Fisheries Science….Read more

This site is a companion for the AFS book Standard Methods for Sampling North American Freshwater Fishes. Increasingly biologists are adopting these methods so they will be able to compare their data to those collected by other organizations, in other regions, or across time. Read more information about standard sampling in general and how these techniques were developed; comment on specific techniques so those working on future editions can incorporate your ideas; compare your fish data to North American, ecoregion, state, and provincial averages and percentiles; and catch up on the latest research on the validation or “ground truthing” of specific standard methods.