Coastal defence through low crested breakwater structures: Jumping out of the frying pan into the fire?

► We assessed the impact of breakwaters (LCSs) on environmental and biological conditions. ► LCSs create pools where environmental conditions are different from the surrounding nearshore. ► LCSs alter the natural pattern and modify seasonal fluctuations of animal assemblages. ► Landward sheltered areas are “lagoonal island” surrounded by a “sea of marine habitat”.