Movement Patterns of American Shad Transported Upstream of Dams on the Roanoke River, North Carolina and Virginia

Abstract

American shad Alosa sapidissima are in decline throughout much of their native range as a result of overfishing, pollution, and habitat alteration in coastal rivers where they spawn. One approach to restoration in regulated rivers is to provide access to historical spawning habitat above dams through a trap‐and‐transport program. We examined the initial survival, movement patterns, spawning, and downstream passage of sonic‐tagged adult American shad transported to reservoir and riverine habitats upstream of hydroelectric dams on the Roanoke River, North Carolina and Virginia, during 2007–2009. Average survival to release in 2007–2008 was 85%, but survival decreased with increasing water temperature. Some tagged fish released in reservoirs migrated upstream to rivers; however, most meandered back and forth within the reservoir. A higher percentage of fish migrated through a smaller (8,215‐ha) than a larger (20,234‐ha) reservoir, suggesting that the population‐level effects of transport may depend on upper basin characteristics. Transported American shad spent little time in upper basin rivers but were there when temperatures were appropriate for spawning. No American shad eggs were collected during weekly plankton sampling in upper basin rivers. The estimated initial survival of sonic‐tagged American shad after downstream passage through each dam was 71–100%; however, only 1% of the detected fish migrated downstream through all three dams and many were relocated just upstream of a dam late in the season. Although adult American shad were successfully transported to upstream habitats in the Roanoke River basin, under present conditions transported individuals may have reduced effective fecundity and postspawning survival compared with nontransported fish that spawn in the lower Roanoke River. Received August 8, 2010; accepted December 30, 2010

Large reservoirs as ecological barriers to downstream movements of Neotropical migratory fish

“…Poddubny and Galat 1995;Gehrke et al 2002;Kruk and Penczak 2003;Falke and Gido 2006;Gido et al 2009) and mainly occur in lotic upper reaches (e.g. Harris and Hightower 2011;Yoon et al 2012). In addition, downstream movements decline as fish enter impoundments due to reduced water velocity and turbulence (e.g.…”

Estimates of Red Drum Mortality via Acoustic Telemetry

“…Monthly observed fates of telemetered Red Drum were inferred from both passive detections and active relocations following previously developed methods (Hightower et al 2001;Bacheler et al 2009a;Ellis et al 2017). Red Drum assigned as alive (fate = 1) were fish that had moved between active relocations, had been detected on more than one receiver in a given month, or had a detection history on a single receiver indicative of movement (time between detections was greater than the maximum ping interval of 90 s; Harris and Hightower 2011). Red Drum that died of natural causes (i.e., natural mortalities; fate = 2) were identified as stationary tags that remained within the river system: either constant detections on a single receiver or active relocations of an individual in the same location for 4 months, with no movement data from the stationary array.…”

Selective fragmentation and the management of fish movement across anthropogenic barriers

“…The idea is that fish are captured on one side of a barrier (depending on whether upstream or downstream passage is being targeted) and then translocated to the other side. This approach has mainly been used for highly valued migratory species such as salmonids, shads and Pacific lamprey (Harris and Hightower , Ward et al. , Lusardi and Moyle ).…”

“…The idea is that fish are captured on one side of a barrier (depending on whether upstream or downstream passage is being targeted) and then translocated to the other side. This approach has mainly been used for highly valued migratory species such as salmonids, shads and Pacific lamprey (Harris and Hightower 2011, Ward et al 2012, Lusardi and Moyle 2017. Capturetranslocation also can be used to maintain gene flow for non-migratory species where populations have become isolated by an anthropogenic barrier (Raeymaekers et al 2009).…”