Conservation of Native Lampreys Worldwide

There are at least 40 species of lampreys worldwide. The exact number varies according to the taxonomy followed. A number of additional species, perhaps 10, remain either undescribed or in synonymy. The 2010 IUCN Red List has categorized 19 lamprey species on a global scale. In order of increasing risk, three are listed as Data Deficient, 10 as of Least Concern, two as Near Threatened, one as Vulnerable, two as Critically Endangered and one as Extinct. Roughly half of the species have, therefore, not been evaluated globally in terms of their conservation status. The threats to the lampreys are numerous and two or more may be acting on a single species. Collectively, the threats involve: 1) habitat degradation through the presence of dams that disrupts migrations and prevents access to spawning sites, spawning habitat decline associated with water extraction for agriculture and gravel extraction for road building, and pollution; 2) severely restricted ranges; 3) severely fragmented distributions; 4) targeted poisoning and; 5) poaching and over-fishing, either of the lampreys themselves or of their food source. Over the last 40 years, many nations have enacted conservation legislation to protect species at risk. In most cases, the extent to which lampreys are recovering due to directed conservation efforts is unknown. However, many initiatives are underway to ameliorate the condition of lampreys. For example, on the west coast of the United States, studies are looking into designing fishways that are better adapted for use by lampreys. Also, after being extirpated in 1958 from its type locality, the Miller Lake Lamprey, Entosphenus minimus is being reintroduced into Miller Lake. A vexing question that has implications in terms of conservation still requires resolution. While it is widely acknowledged that the Sea Lamprey, Petromyzon marinus invaded the upper three Laurentian Great Lakes via Lake Erie around the mid 1930s, the status of the Lake Ontario Sea Lamprey population as either a native or an invasive species is still not settled, because studies seeking to establish its proper identity have produced contradictory results. This is an important issue to settle because various control measures directed towards the Sea Lamprey in Lake Ontario have remained in effect since at least 1972. If it is determined that the Sea Lamprey in Lake Ontario is in fact native, then these measures would need to be re-evaluated.