GAM results showing effects of environmental factors on percent cover of W. subtorquata across four Korean harbors from April 2021 to July 2024: Yangpo (A, B), Tongyeong (C, D), Bieung (E, F), and Jeju (G, H). A, C, E, G. Effect of water temperature with constant salinity; B, D, F, H. Effect of salinity with constant water temperature. Shaded bands represent 95% confidence intervals (± 1.96 SE) around the fitted GAM smooths.