Sessile macrobenthic assemblages on shallow subtidal rocky reefs – Adriatic Sea (Mediterranean Sea)
Description
This data set is the result of a manipulative experiment carried out as a part of research activities supported by the European Community within the 7th Framework Programme (FP7/2007−2013) for the project ‘Towards COast to COast NETworks of Marine Protected Areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential (CoCoNet)’, Grant Agreement No. 287844. The experiment was carried out at seven locations representative of shallow subtidal rocky reefs in the Adriatic Sea. In most cases locations were selected within Marine Protected Areas (MPAs), natural parks or reserves, or other areas included in current and future conservation plans, in order to assess the connectivity potential of the existing and projected network of protected areas in the basin. Locations were: MPA of Tremiti islands (42° 7'11.24"N - 15°29'2.25"E), MPA of Torre Guaceto (40°42'59.46"N - 17°47'59.77"E), EU Special Area of Conservation, Otranto (40° 7'13.53"N - 18°30'39.38"E); Croatia: Kornati Islands National Park (43°49'14.68"N - 15°14'5.37"E); Montenegro: Herceg Novi (42°22'46.96"N - 18°34'49.96"E); Albania: Karaburun-Sazan National Park (40°24'1.45"N - 19°18'52.99"E); Greece: EU proposed Site of Community Importance, Othonoi Island (39°50'7.27"N - 19°23'29.86"E). For each location, three random sites (1-5 km apart) characterized by comparable conditions, in terms of type and slope of the substrate and exposure, were identified. At each site, six square patches (few meters apart, each approximately 2 m2) were randomly selected on sub-horizontal rocky bottoms at 5-7 m depth and permanently marked at the four corners with screws and epoxy putty. Three of the six patches were randomly chosen and experimentally disturbed by removing the resident assemblages from the substrate. Epibenthic assemblages in treatment patches were scraped off with chisels and hammers. Steel brushes were used to remove organism remains after treatment. The other three patches were left untouched and used as reference during the experiment. The experimental setup started in June 2013 and treatments in all locations were performed within one months. Sessile assemblages were sampled in five sampling occasions, one at the beginning of the experiment (July-August 2013, undisturbed patches only) and then at 3 (October-November 2013), 9 (April-May 2014), 12 (July-August 2014) and 24 (July-August 2015) months since disturbance. Three random 400 cm2 photographic samples were taken in each patch for each time of sampling by using a digital underwater camera equipped with strobes. A total of 1,701 photographic samples were collected and analyzed to identify epibenthic organisms. Vagile organisms were not considered in the analysis. A total of 70 taxa/groups, most of them (~80%) at the level of species or genus were recorded. Data reported assemblage composition (presence/absence) for each site, separately for disturbed and undisturbed assemblages, in each time of sampling.