Sure It’s Big Enough, but Look at the Location! Using Odors to Guide Sea Lamprey Towards a Barrier-integrated Trap

Due to their proclivity for nocturnal endeavors, lampreys likely rely heavily (but not exclusively) on their sense of smell. This sense may be of particular importance during migration when, for example, visual cues may be lacking. The acute nature of this ability allows lampreys to locate suitable spawning habitat by indicating the presence of stream-resident larvae and/or sexually receptive mates, whilst highlighting potentially harmful areas en route. By attending to such cues as they do, lampreys are therefore vulnerable to behavioural manipulation by managers - where it is possible to mimic the nature of those odors. Here I present recent findings from a field study that employed both a repellent and attractant odor to manipulate the spawning migration of sea lamprey in the vicinity of a barrier. By activating a portion of a stream channel with a putative alarm cue we induced sea lamprey to locate the entrance to a barrier-integrated trap significantly faster than when no odor was applied - as a result of their redistribution within the stream while actively migrating. These data suggest similar strategies could be utilized to assist lampreys in locating fishway entrances at similar barriers.