| dc.description.abstract | Brook Trout (Salvelinus fontinalis) populations and habitat conditions are adversely
affected by anthropogenic impacts that could impact abundance and distribution of Brook
Trout at different spatial scales. My goal was to examine environmental DNA (eDNA) and
underwater video cameras (UWVC) as alternative sampling methods to conventional
(electrofishing) methods for measuring abundance and distribution of Brook Trout in
stream environments across two sampling years (2019, 2020). My second goal was to use
the same alternative sampling methods to examine Brook Trout-habitat associations at
three spatial scales and to determine whether the habitat associations are unique to one
spatial scale or common among spatial scales. The three spatial scales examined were the
segment (>200m), reach (50m) and microhabitat (1m2
) scale. Environmental DNA
concentrations and UWVC surveys showed a strong agreement with Brook Trout
presence/absence (89% and 78%, respectively) and estimated abundance but significant
interannual variation existed for both methods between sampling years. Habitat
associations determined that Brook Trout are associated with both scale-specific habitat
characteristics (i.e., canopy cover at the reach scale, baseflow index at the segment scale)
but were also strongly associated with common habitat characteristics (i.e., surface
temperature, stream width, watershed size (km2
) and discharge). The results of this study
support the use of eDNA and UWVC as alternative methods to electrofishing for
determining the presence/absence of Brook Trout and abundance. These results also
suggest that both scale-specific habitat variables and habitat variables measured across
scales are important factors for Brook Trout abundance and highlights what key habitat
characteristics fisheries managers should prioritize for management. | en_US |
