Use of Prepositioned Grid Electrofishers for the Collection of Robust Redhorse Broodstock

Abstract

We investigated the potential of prepositioned grid electrofishers as a means of collecting broodstock for the rare robust redhorse Moxostoma robustum. We found that combined with visual observation, this technique allowed for the efficient capture of fish in breeding condition. We were able to harvest eggs in the field and bring only fertilized eggs into the hatchery. There was no need to induce spawning hormonally. Although their use is limited by water depth and clarity, prepositioned grid electrofishers used in conjunction with visual observation warrants further consideration as an effective tool for the collection of reproductively active broodstock for conservation purposes.

Spatial and temporal segregation of spawning habitat by catostomids in the Savannah River, Georgia and South Carolina, U.S.A.

“…Prepositioned grid electrofishers were deployed as described by Grabowski & Isely (2005) to capture spawning and staging fishes. A GPS waypoint, depth, current direction, current velocity and substratum particle size distribution was taken at each grid prior to retrieval.…”

Demographics of the spawning aggregations of four catostomid species in the Savannah River, South Carolina and Georgia, USA

“…2005; Grabowski & Isely 2006). However, catostomids tend to form spawning aggregations in shallow water where they are vulnerable to various sampling gears (Jenkins & Burkhead 1993; Grabowski & Isely 2005, 2007a). As part of an ongoing study, we were able to collect data from a large number of catostomids captured from their spawning habitat.…”

“…The lack of basic life history and demographic data available for some riverine catostomids may be partially a reflection of difficulties capturing sufficient numbers of these fishes in large rivers (Cooke et al 2005;Grabowski & Isely 2006). However, catostomids tend to form spawning aggregations in shallow water where they are vulnerable to various sampling gears (Jenkins & Burkhead 1993;Grabowski & Isely 2005, 2007a. As part of an ongoing study, we were able to collect data from a large number of catostomids captured from their spawning habitat.…”

Efficiency of Two‐Way Weirs and Prepositioned Electrofishing for Sampling Potamodromous Fish Migrations

“…Fish assemblages were sampled during April 20-June 30, 2006, andMarch 27-June 6, 2007. Weir and PAE samples were collected concurrently on two consecutive days per week. Prepositioned areal electrofishers were constructed based on the designs of Fisher and Brown (1993) and Grabowski and Isely (2005); weir construction and installation followed methods described by Torbin (1994), Mogen (1996), and Stewart (2002Stewart ( , 2003.…”

“…Conventionally, weirs have been used to capture broodstock for terminal fisheries, quantify age structure, determine condition status, estimate adult sex ratio, determine spawning escapement, estimate smolt production, and identify migratory patterns; weirs are often the standard against which other gears are evaluated (Zimmerman and Zabkar 2007;Hubert et al 2012). Prepositioned areal electrofishers are increasingly used to sample lotic habitats and typically are employed to obtain occurrence and abundance estimates (Lee and Suen 2013;Weaver et al 2014), identify microhabitat use while eliminating fright bias (Bain et al 1985;Aadland 1993;Fisher and Brown 1993;Schwartz and Herricks 2008;Lee and Suen 2013), collect broodstock while maintaining natural selection integrity (Grabowski and Isely 2005), estimate unbiased species richness (Bowen and Freeman 1998;Walsh et al 2002), and calibrate biased snorkel survey data (Weaver et al 2014). Many potamodromous fishes (e.g., Moxostoma spp.)…”