Fig. 7

Summed effects of nonlinear interaction between distance (m) and environmental variables on detection efficiency (DE) for V9 tags and V16 tags from deployments in northeastern Lake Ontario: a thermocline index for V9; b thermocline index for V16; c surface water velocity (m·s⁻¹) for V9; d surface water velocity (m·s⁻¹) for V16; e ice thickness (m) for V9; f ice thickness (m) for V16; g temperature at 50 m (°C) for V9; h temperature at 50 m (°C) for V16. Thermocline index represents the strength of the thermocline where zero signifies thermal homogeneity and values increasing in either direction from zero indicate an increasing thermal gradient. Contour lines and colour represent DE (0–1)