Past and Present Distribution and Identification of Extant Native Lake Trout (Salvelinus namaycush) Populations in the Canadian Maritime Provinces

Salvelinus namaycush (Lake Trout) occur in the Canadian Maritime Provinces of New Brunswick and Nova Scotia, and are absent in Prince Edward Island. Lake Trout are assumed to be native in parts of New Brunswick, but their ancestry in Nova Scotia is unknown. Starting in 1886, stocking was used to spread Lake Trout across lakes in the Maritime Provinces to bolster existing populations and to create new fishing opportunities. The success of most stocking efforts was not well documented, and it is presumed that many of these efforts failed. After the early stocking from which some populations persist, little effort has been made to understand the distribution, stock structure, or ancestry of Lake Trout in this region. This review is a synthesis of Lake Trout distribution in the Canadian Maritime Provinces, including a comprehensive account of stocking history, proposed native population occurrence, and identification of populations with variable ancestry. At present, Lake Trout occur in 20 lakes in New Brunswick (19 confirmed and 1 potential), and 4 lakes in Nova Scotia (2 confirmed and 2 potential). Native Lake Trout may persist in 12 of 15 New Brunswick lakes and 3 of 9 Nova Scotia lakes that historically contained ancestral Lake Trout populations. Of these lakes with historical populations that persist to this day, 10 in New Brunswick and 1 in Nova Scotia were supplemented with introduced stock; therefore, only 2 lakes in New Brunswick and 2 in Nova Scotia are likely to still contain purely native Lake Trout. By improving the understanding of population structure and origins, this synthesis provides information that is critical for the effective management and conservation of native Lake Trout in the eastern Maritime region.