*2.2. Sampling Method*

Field sampling was conducted in Spring 2021 (28 April to 1 June). A total of 24 sampling spots (i.e., 6 for each of the 4 levels) were monitored at low tide. The sampling spots were referenced using pictures and GPS positioning (Garmin GPS 73, ±3 m). The sampling protocol followed the methodology described in Burel et al. (2019b) [59]. A mobile plastic grid structure of 1.65 m × 1.65 m divided into 25 quadrats of 33 cm × 33 cm was used to delimit each sampling spot. Covers of benthic fauna, flora and bare rock were estimated visually on the entire surface delimited by the plastic structure from 0 to 100 percent, with a 5 percent pace. That approach, known as 'undisturbed sampling', describes the distribution of the main groups of benthic organisms plus the substratum during emersion.
