Neighborhood benthic configuration reveals hidden social diversity: classified benthic data

a) Study Sites The field data selection coincided with a program to quantify changes in the sessile community along a depth gradient in multiple locations of two distant geographic areas. The Spanish islands of Illes Medes and L'illa de Benidorm are located in the Mediterranean Sea and are nature reserves. L'illa de Benidorm is located about 3.5km from the coast, near Benidorm, and has been part of the Sierra Helada Natural Park since 2005. Illes Medes is an archipelago of seven islands about 0.85 km from L'Estartit. It has been protected since 1983 and became a National Protected Natural Park in 2010. These two locations were selected due to their proximity to the coast, ease of sampling, rocky bottoms, and because they are island enclaves close to the coast. b) Sampling design During May and June 2010, 6 dive sites in Illes Medes and 2 dive sites in L'illa de Benidorm were selected. For each site, except Garbí and Gros due to a lack of suitable substrate, a photophilous aspect was paired with a sciaphilous aspect. To capture the impact of depth on the community assemblages, each site was surveyed at different depths along the rocky reef wall at 2, 4, 7, 14, and 23 m deep. The sciaphilous aspects could not be located for the 2 sites in L'illa de Benidorm and only one set of transects at various depth profiles were photographed. Based on the continuous line transect method, photo quadrats using a camera (Sony Cyber-shot Vario-Tessar 10.1 Mpx with a constant 45cm distance measurement frame) covered a 5m long transect for each depth profile. Approximately 25 overlapping images were captured per transect. Later back in the laboratory, we identified every species (where possible) directly next to the photographed transect tape for each centimeter division so that 500 data points were recorded per transect. The final dataset contains 17 sites with five depth transects, resulting in 85 sets of benthic data.