A critical review of the discovery and application of a migratory pheromone in an invasive fish, the sea lamprey Petromyzon marinus L.

The sea lamprey Petromyzon marinus, an ancient and parasitic agnathan fish native to the North Atlantic, invaded the Laurentian Great Lakes approximately a century ago triggering its fisheries to collapse. Presently, this species is held in check through a toxicant-based control programme directed by a bi-national treaty organization that seeks to develop a more broadly based integrated pest management (IPM) strategy. After a long and difficult search, the most active components of a migratory pheromone for the sea lamprey were identified and synthesized. This pheromone has remarkable potency and considerable potential to enhance various control strategies that fall within an IPM scheme. The pheromone is comprised of a mixture of at least three sulphated steroids: petromyzonamine disulphate (PADS), petromyzosterol disulphate (PSDS) and petromyzonol sulphate (PS). A steroidal sex pheromone appears to have similar promise. These discoveries, which are prompting development of the first pheromonally guided pest management programme for an invasive fish, have revealed significant scientific and policy challenges. Among the former are the needs to acquire long-term and significant support for the science, to synthesize sufficient quantities of cues, and to deploy and measure pheromonal components in natural waters. Among the latter are the needs to regulate this new type of 'pesticide', protect these technologies from exploitation and promote future research on this and other invasive fish species. Lessons from these experiences may be applicable to the study of other invasive fishes.