Variability of Benthic Communities in Relation to Hydrodynamic Conditions in the North-Eastern Baltic Sea

Wave forcing is an important hydrodynamic variable that influences spatial patterns and temporal dynamics of marine benthos. In this study, we used three principally different wave models simplified wave model (SWM), spectral wave model SWAN (simulating waves nearshore), and locally calibrated point model (LCPM) to assess the effects of wave forcing on the distribution and temporal dynamics of macrobenthos in the north-eastern Baltic Sea. Other important environmental variables like depth, salinity, turbidity etc., were also included into analyses of benthos distribution in order to quantify the relative importance of wave forcing. Following depth, SWM was the second most important environmental predictor of spatial distribution of benthos. The importance of SWAN was the lowest among environmental variables due to its low spatial resolution (1 nautical mile) compared to SWM (25 rn). Considering the temporal dynamics of benthos, wave height significantly correlated with several benthic variables, but the direction and magnitude of effects were site-specific.