Hearing Sensitivity of the Burbot

Abstract

Acoustic communication is central to the reproductive ecology of many fish species, particularly when conditions prevent the use of visual mating cues. The Burbot Lota lota is a freshwater codfish that spawns in a light-limited, under-ice environment. Both sexes possess swim bladder muscles, suggesting that both sexes engage in vocalization and that auditory cues are important to their mating system, but research on acoustic communication has been very limited in this species. In the current study we assessed the hearing sensitivity of Burbot from different size-classes. Burbot hearing was found to be more sensitive in juveniles than in adults, but across size-classes it was most sensitive at lower frequencies, which is similar to results with other codfishes and corresponds to the sounds produced by gadoids. Anthropogenic noise has the potential to disturb fish. The information gained in this study can be useful in assessing the impact of such noise, particularly under ice cover when Burbot are spawning. Further research is required to determine whether winter-based resource development activities that generate under-ice noise are disruptive to Burbot communication and reproduction.

Received September 5, 2012; accepted March 13, 2013

ACKNOWLEDGMENTS

We thank Carl Jorgensen for field assistance and Jim Reist and Jeff Hutchings for review of earlier drafts. Critical peer review provided by David Jude, Martin Stapanian, and two anonymous reviewers was highly constructive. This work was funded by Natural Resources Canada through the Program of Energy, Research, and Development and under the guidance of Animal Use Protocol FWI-ACC-2009-063.