Monitoring lake populations of Eastern Sand Darter (Ammocrypta pellucida): a comparison of two seines

Abstract

For many imperiled fishes in the Laurentian Great Lakes basin, detection protocols and population monitoring programs are lacking. In this study, we used a repeat-sampling approach to compare the effectiveness of two seines (bag and beach) to detect and characterize the abundance of lakedwelling populations of Eastern Sand Darter (Ammocrypta pellucida); a threatened species in Canada. Compared to the bag seine, the larger beach seine collected a greater number of Eastern Sand Darter and detected the species at more sampling sites. Model-averaged estimates of detection probability were also greater for the beach seine (p = 0.72) than bag seine (p = 0.48). A decline in catch over repeated seine hauls occurred at less than a third of the sample units. Mean capture probabilities were 0.41 in units sampled by beach seine, and 0.37 in units sampled by bag seine, when depletion occurred. Sizes of Eastern Sand Darter collected by each seine were significantly different, with fewer small (<40 mm total length) individuals found in bag seine hauls. Power analyses indicate that data collected with either seine are expected to detect changes in local distribution of 50% or greater. Power to detect future changes in Eastern Sand Darter abundance of 50% or greater is predicted to be higher for the beach seine, and to increase with the number of seine hauls at a site. Catch differences between seines are interpreted to reflect the greater area sampled by the larger beach seine.

Using GIS to predict habitat in lakes: An example using nearshore substrate categories

“…Our GIS framework may also be useful to prioritize sampling areas for species of interest in new systems. For example, predicted sandy shoals would be priority‐sampling locations for Eastern Sand Darters Ammocrypta pellucida, a species of conservation concern in much of North America (Reid and Dextrase ).…”

Comparison of three sampling methods for small-bodied fish in lentic nearshore and open water habitats

“…Beach seining is also limited by depth and samples relatively small water volumes per haul (LaPointe et al, 2006;Lyons, 1986;Pierce et al, 1990). Alternatively, trawls can sample relatively large open water volumes over a short period and have been commonly used to collect small-bodied fishes in open lentic fresh and estuarine waters (Feyrer et al, 2015;Herzog et al, 2009;Reid & Dextrase, 2017;Vorwerk et al, 2008). However, trawls are comparatively inefficient, lack maneuverability, and can alter fish behavior, making them inappropriate for sampling shallow, complex lentic habitats (Engås et al, 1998;Kaartvedt et al, 2012).…”