Multibeam sonar (DIDSON) assessment of American shad (Alosa sapidissima) approaching a hydroelectric dam

Abstract

We investigated the fish community approaching the Veazie Dam on the Penobscot River, Maine, prior to implementation of a major dam removal and river restoration project. Multibeam sonar (dual-frequency identification sonar, DIDSON) surveys were conducted continuously at the fishway entrance from May to July in 2011. A 5% subsample of DIDSON data contained 43 793 fish targets, the majority of which were of Excellent (15.7%) or Good (73.01%) observation quality. Excellent quality DIDSON targets (n = 6876) were apportioned by species using a Bayesian mixture model based on four known fork length distributions (river herring (alewife, Alosa psuedoharengus, and blueback herring, Alosa aestivalis), American shad, Alosa sapidissima) and two size classes (one sea-winter and multi-sea-winter) of Atlantic salmon (Salmo salar). 76.2% of targets were assigned to the American shad distribution; Atlantic salmon accounted for 15.64%, and river herring 8.16% of observed targets. Shad-sized (99.0%) and salmon-sized (99.3%) targets approached the fishway almost exclusively during the day, whereas river herring-sized targets were observed both during the day (51.1%) and at night (48.9%). This approach demonstrates how multibeam sonar imaging can be used to evaluate community composition and species-specific movement patterns in systems where there is little overlap in the length distributions of target species.

Manual fish length measurement accuracy for adult river fish using an acoustic camera (DIDSON)

“…The variance of the L D was mostly explained by the operator effect in our study. Grote et al (2014) also used repeated measures with several operators and compared L D with L T . They showed an operator effect but with a small mean error.…”

Intake Approach and Dam Passage by Downstream‐migrating Atlantic Salmon Kelts

“…dual-frequency identification sonar, Simsonar Underwater Video Camera (UVC); from here on acoustic sonar) uses echoing sound waves to obtain images for identification of objects underwater (Moursund et al, 2003;Grote et al, 2014). The technology has been used, for example, to enumerate migrating fish (Pipal et al, 2010;Pipal et al, 2012), detect fish species downstream of dams (Grote et al, 2014), evaluate fish passage through tidal flood gates (Doehring et al, 2011) and study fish behaviour in relation to fishing gear (Rose et al, 2005;Rakowitz et al, 2012). Acoustic sonar offers a noninvasive method to study live, migrating fish without interfering with their natural behaviour.…”

Assessment of River Herring Spawning Runs in a Chesapeake Bay Coastal Plain Stream using Imaging Sonar

“…Imaging sonar has proven to be a powerful tool for conducting run counts for stock assessment in shallow streams several meters or less in depth and, importantly, can be used in turbid streams without narrow fish passage structures (Holmes et al 2006;Martignac et al 2014). Although river herring are small (200-350 mm TL) and thus challenging to image using sonar (Hightower et al 2013), imaging sonar has been used to conduct run counts for a variety of species groups including river herring (Magowan et al 2012) and salmonids Mueller et al 2010;Pipal et al 2010;Jones and Petreman 2015) and multispecies assemblages that include river herring (Grote et al 2014;Hughes and Hightower 2015). It is not possible to differentiate between Alewife and Blueback Herring using imaging sonar, necessitating additional biological sampling to estimate species-specific run counts for river herring (Magowan et al 2012;Grote et al 2014;Hughes and Hightower 2015).…”