Fig 1.
Map of study area, showing Minas Basin and an inset of Gaspereau River and Gaspereau Lake.
The tagging site at White Rock Fish Ladder is designated by a black diamond.
Fig 2.
Pictures of holding tank (270 L) used to retain alewives during field trials at the White Rock Fish Ladder, Gaspereau River, Nova Scotia.
Both the holding and recovery tanks were analogous and located outdoors near the fish ladder on Nova Scotia Power Inc property.
Table 1.
Average weight, length and water temperature parameters of alewife trial groups across the 2018 and 2019 field seasons.
Fig 3.
Position of the incision in red (top) and tag (bottom) following surgical implantation on the right lateral side of the fish, with internal anatomy shown.
Table 2.
Physical index examined at necropsy.
Fig 4.
Anesthesia induction (a) and recovery (b) times at 15˚C for MS-222 concentrations of 60 mg/L, 100 mg/L and 200 mg/L. Times were capped at 5-minutes. * P < 0.05; ** P < 0.01; *** P < 0.001 one-way ANOVA with Tukey's Honestly Significant Difference (HSD) post hoc test.
Fig 5.
Treatment (a) and recovery (b) times of incision-only, sutured and non-sutured trial groups tagged with dummy V5 acoustic tags at an average temperature of 15˚C. ** P < 0.01 one-way ANOVA with Tukey's Honestly Significant Difference (HSD) post hoc test.
Fig 6.
(A) Change in RAMP scores as a function of water temperature during tagging. Red line represents general linear regression with quasibinomial error distribution and 95% confidence intervals. Zero-intercept shown by the dashed blue line. (B) Boxplots showing median and quartile range of physical impairment scores for pre and post-spawned alewives, with whiskers at 1.5 IQR of the upper/lower quartiles. Outliers are shown in red. *** P < 0.001 GLM.