The Pollan or Irish Pollan (Coregonus pollan) is a freshwater whitefish that is known only from five Irish lakes, Lough Neagh, Lower Lough Erne, Lough Ree, Lough Derg and Lough Allen.
Endangerment[]
The pollan populations are threatened by ecosystem changes such as eutrophication and increases in introduced species including pike, roach and zebra mussel. Only the population of Lough Neagh in Northern Ireland remains abundant and supports a small commercial fishery. The other UK population in Lough Erne has severely declined. The Lough Allen population was only confirmed for the first time in 2006. Other populations rely on stocking for their survival.
Classification[]
In scientific literature and in national biodiversity and conservation assessments, the Irish pollan are usually classified within the species Coregonus autumnalis. That is a widespread anadromous whitefish which inhabits coastal waters and rivers of Arctic Siberia, Alaska, and Canada and is there known as the Arctic cisco or Siberian omul. C. autumnalis is not distributed elsewhere in northwestern Europe, and the pollan are often given a status of subspecies as Coregonus autumnalis pollan. These classifications are based on the close genetic similarity of the Arctic and Irish whitefish populations. By IUCN, the Irish pollan is however listed as a distinct fish species Coregonus pollan, whereas FishBase refers to it alternatively as a species or as part of the Arctic C. autumnalis.
Unlike its Arctic relatives, the Irish pollan does not migrate to the sea.