Grabowski TB. 2016. Assessing the feasibility of using acoustic monitoring for Burbot conservation, management, and production. Report provided by the Cooperative Fish and Wildlife Research Unit Program under agreement with the U.S. Fish and Wildlife Service. U.S. Department of Interior, Fish and Wildlife Service, Cooperator Science Series FWS/CSS-118-2016, National Conservation Training Center.
Abstract
Burbot Lota lota is the sole freshwater representative of the cod-like fishes and is a commercially and recreationally important species found worldwide above approximately 40° N. It is a difficult species to effectively manage due to its preference for deep-water habitats and that its spawning and other aspects of its early life history are completed under the ice in winter. Like most gadiform fishes, Burbot use acoustic signaling as part of their mating system, and while the acoustic repertoire of the species has been characterized under artificial conditions (i.e., net pen suspended under ice in a natural lake), there has been no work to determine whether the species is as vocal in natural spawning aggregations. Our objective was to assess the feasibility of collecting and using acoustic data to characterize the spawning activity and locations of Burbot under field conditions. We recorded audio and video of Burbot spawning aggregations through holes drilled into the ice at known spawning grounds at Moyie Lake in British Columbia, Canada. Acoustic recordings were analyzed using Raven Pro v 1. 4 to count the number of calls and their characteristics. Acoustic behavior was also related to the video data to determine how acoustic activity correlates to any observed spawning behavior. In general, wild Burbot spawning in Moyie Lake do not vocalize as frequently as counterparts spawning under artificial conditions. Further, Burbot vocalizations were not recorded in conjunction with spawning activity. While it may be feasible to use passive acoustic monitoring to locate Burbot spawning grounds and identify periods of activity, it does not seem to hold much promise for locating and quantifying spawning activity in real time.