Effects of capture depth on walleye hooking mortality during ice fishing

Figures & data

Table 1. Mean parameter values used to assess factors affecting hooking mortality of walleye during ice fishing season on Lake Oahe and Lake Sharpe in 2020.

Variable	Mean value
Landing time (T0 to T1, s)	26.3 (1.4)
Capture depth (m)	10.9 (0.2)
Total length (mm)	342 (8.8)
Time in pen (days)	3.0 (0.1)
Pen density (fish/m^3)	0.4 (0.02)
Handling time (T0 to T4, s)	219 (25)
Barotrauma (n)	18
Foul-hooking (n)	2
Bleeding (n)	2

Values in parentheses represent 1 standard error.

Table 2. Number of model parameters (K), Akaike’s information criterion (AICc) values, difference between AICc values, model weights (w_i), and evidence ratios for top logistic regression models evaluating probability of hooking mortality (${\mathrm{p}}_{\mathrm{m}}$) in Lake Oahe and Lake Sharpe, 2020.

Model	K	AICc	ΔAICc	wi	Evidence ratio
Capture depth	2	47.1	0.0	0.5	1.0
Capture depth + landing time	3	47.6	0.5	0.4	1.3
Capture depth + landing time + time in pen	4	49.1	2.0	0.2	2.7

Table 3. Logistic model variables predicting probability of hooking mortality ($p_m$) in walleye during winter of 2020 in Lake Oahe and Lake Sharpe.

	Logistic coefficient	S.E.	Odds ratio	95% CI (LL, UL)	P > chi squared
Intercept	–15.0	5.00			<0.01
Capture depth	1.20	0.43	3.33	1.43, 7.76	<0.01

Figure 1. Probability of hooking mortality ($p_m$) of walleye caught in Lake Oahe and Lake Sharpe in winter of 2020 as a function of capture depth (m). Dashed lines indicate 95% confidence intervals.

Data availability

The datasets analyzed for the study are available from the corresponding author on reasonable request.