摘要：We examined the influence and relative importance of fine sediment on wild brook trout (Salvelinus fontinalis) populations in a forested watershed. Brook trout spawning substrate was generally comprised of 75% particles < 32 mm, with approximately 27% < 4.0 mm. Brook trout production was inversely proportional to substrate permeability in one of two years, suggesting substrate composition was influential in regulating recruitment. In that year, age-0 brook trout abundance was negatively influenced by the amount of fine sediment < 0.063 mm. We identified that for brook trout the critical fine sediment size influencing recruitment as between 0.063 and 1.0 mm. The lack of a relationship between age-0 brook trout recruitment and abundance in a second year was thought to be the consequence of severe drought causing fine sediment levels to exceed 1% < 0.063 mm in spawning substrate in all streams. Habitat variables were not related to age-0 brook trout abundance or biomass suggesting that under normal flow conditions, fine sediment was a principal determinant of juvenile trout abundance relative to other physical and biological factors.
