SharkDefense and the Wagner Research Group at Michigan State University are collaborating on projects to control sea lampreys in the Great Lakes.

The sea lamprey, Petromyzon marinus, is a rapacious parasite of large-bodied fishes; multiple attacks from its rasping suctorial mouth typically result in the death of the host. Invasion of the Laurentian Great Lakes by the sea lamprey resulted in near extinction of the dominant piscivore (lake trout, Salvelinus namaycush ), contributed to the extinction of three endemic fishes – the deepwater cisco (Coregonus johannae), the shortnose cisco (C. reighardi), and the blackfin cisco (C. senithicus) – and set the stage for a population explosion by two invasive prey fishes (alewife, Alosa psuedoharengus, and rainbow smelt, Osmerus mordax). The US and Canadian governments now undertake an integrated pest management program to suppress sea lamprey populations by reducing recruitment to the parasitic stage (pesticide application) and suppressing reproduction (barriers to spawning migrations, sterile male introduction) (Christie and Goddard 2003).

We've recently confirmed a long-standing anecdotal observation: sea lamprey are chemically aware of, and actively avoid, the odor emitted by dead conspecifics (a so-called necromone). Such avoidance is typically thought to be an indirect response to the threat of predation, revealed through the odor emitting from ruptured or decaying conspecifics (reviewed by Chivers and Smith 1998, Yao et al. 2009). Because predation is one of the most pervasive and powerful selection pressures on individual fitness (Lima and Dill 1990, Wisenden 2000, Brown 2003), there is considerable evidence that indirect predator cues, conveyed through olfactory channels, are used by many species to assess risk associated with space and resource use (e.g., Turner 1997, Dicke and Grostal 2001, Brown 2003). We are currently investigating whether and how the sea lamprey utilizes innate responses to conspecific mortality at least twice in its life-history (stream-resident larvae and migrating immature adults). In both cases, we believe the cue regulates spatial habitat use.

Recent Awards:

• 2010. Great Lakes Fishery Commission. Development of a Putrefaction-Derived Repellent for the Sea Lamprey.
• 2010. Michigan State University, Center for Water Sciences Venture Grant. "Preliminary identification of a putrefaction-derived repellent for the invasive sea lamprey (Petromyzon marinus)"