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Stocked‐Fish Introgression into Wild Brook Trout Populations Depends on Habitat
Author(s) -
Bruce Spencer A.,
Kutsumi Yuka,
Van Maaren Chris,
Hare Matthew P.
Publication year - 2020
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1002/tafs.10239
Subject(s) - stocking , trout , salvelinus , biology , introgression , population , ecology , genetic diversity , genetic monitoring , brood , habitat , fishery , fontinalis , genetic structure , effective population size , microsatellite , fish <actinopterygii> , demography , biochemistry , allele , sociology , gene
The genetic constitution of populations is affected by myriad factors, including both natural and anthropogenic habitat transformations. Previous work on the population structure of Brook Trout Salvelinus fontinalis has suggested that supplemental stocking for fishery enhancement has transformed natural genetic diversity. We utilized microsatellite analysis of 11 loci to examine the genetic structure of over 950 Brook Trout sampled across 50 locations, including hatcheries; holding ponds; wild, unstocked waters; and repeatedly stocked waterbodies across Adirondack lakes and ponds in New York State, USA. From these data, we estimated the degree of introgressive hybridization, tested for associations with landscape and stocking variables, and tested predicted patterns of genetic diversity, effective population size, and genetic population structure. Widespread repeated stocking of a single hybrid strain has led to the dramatic genetic homogenization of Brook Trout across the sampled lakes and ponds. Model selection indicated that environmental factors were more important than stocking intensity for determining the extent of stocked‐fish introgression, and certain environmental circumstances may make some populations relatively resilient to repeated stocking activities. Known, protected heritage strains were confirmed as mostly unadmixed, but holding ponds with heritage brood populations used for supplemental stocking had become differentiated from the natal strains in two of the three cases tested. In addition to the importance of these results for understanding the effects of stocking activities on the genetic integrity of Brook Trout populations, our findings illustrate how current genetic techniques can aid in the development of management practices that are related to the conservation of species supporting economically important freshwater fisheries.