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
North American Journal of Fisheries Management
Marine and Coastal Fisheries
Shrimp trawls are one of the main bycatch generators in artisanal fisheries. Our work evaluated the adoption of low cost devices for artisanal bottom trawling to reduce bycatch assimilation and improve shrimp catches. To evaluate the proposed changes, we evaluated the performance of four different trawl gears from May to July 2015 in Pinheira Beach, Brazil. The hauls were divided into four treatments as follows: (1) hauls with unmodified control gear, (2) hauls with gear that included the kite escape device (KED), (3) hauls with gear that included long sweeps, and (4) hauls with gear that included both the KED and long…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.