There and Back Again: Lampreys in the 21st Century and Beyond

Abstract

The 21st century is proving to be an exciting time to study lamprey biology. Lampreys have long provided important insights into key developments in vertebrate evolution; research in support of sea lamprey control in the Laurentian Great Lakes has made significant contributions to our understanding of lamprey biology; and there is now (near) global interest in the conservation of threatened lamprey species. Furthermore, we are beginning to see a convergence of these formerly discrete research areas, as well as greater interactions and knowledge exchange between researchers and managers from different geographic regions. In this conclusion to Volumes 1 and 2 of Lampreys: Biology, Conservation and Control, we provide an overview of some exciting advances in our knowledge of lamprey biology and potential challenges facing lampreys and lamprey biologists in the near future. Recent advances and remaining knowledge gaps in many aspects of fundamental lamprey biology are covered in other chapters in these two volumes; here, we focus on the intersection of biology, conservation, and control. For example, molecular analysis has resolved many of the previous uncertainties regarding lamprey phylogenetic relationships, but continued uncertainties (e.g., the relationship between “paired” parasitic and non-parasitic lampreys) and lack of an explicit phylogenetic framework contribute to ongoing confusion among biologists regarding correct lamprey nomenclature. Although lamprey taxonomy will no doubt continue to be revised as we refine our hypotheses regarding the evolutionary relationships among lampreys, it is important that we: (1) use consistent and accepted species names to enable accurate communication between researchers and managers from different regions; and (2) recognize that conservation legislation acknowledges biological diversity below the species level (i.e., evolutionarily significant units, ESUs) so that genetically or otherwise distinct lamprey populations are eligible for protection without prematurely or inconsistently describing each as a distinct species. Novel methodologies that are contributing to our understanding of lamprey biology and that have exciting applications to lamprey conservation and control include: (1) improvements to deepwater larval sampling methods to help evaluate the extent to which lentic and deep riverine habitats are used by different lamprey species; (2) improved tools for monitoring the spawning migration; (3) environmental DNA (eDNA) and pheromone detection assays that have the potential to provide cost-effective supplements to traditional lamprey survey methods; and (4) genetic and genomic tools that are being used in a variety of ways to help refine our understanding of lamprey biology (e.g., mating systems, larval dispersal and growth rates) and to aid conservation and control efforts (e.g., elucidating genetic stock structure, monitoring the success of translocation efforts). Not surprisingly, advances and challenges related to lamprey control and conservation are often “two sides of the same coin.” This is particularly true with respect to passage of upstream migrants at anthropogenic barriers, and knowledge of lamprey behavior at barriers is being used to both block sea lamprey migration in Great Lakes tributaries and enhance passage efficiency for other lampreys elsewhere. Achieving successful lamprey conservation and control will also require positive public and legislative attitudes towards species in need of conservation and continued public support and acceptance of sea lamprey control efforts. Pursuit of genetic control options in particular will need to address ethical and societal concerns.