Sessile assemblage composition Adriatic Sea (P/A)

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. Five 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 2,835 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.

本数据集为一项操控性实验的成果，该实验作为研究活动的一部分，由欧盟委员会第七框架计划（FP7/2007−2013）资助，对应项目为“面向海岸到海岸的海洋保护区网络（从近岸至远海及深海），耦合海上风能潜力（CoCoNet）”，资助协议编号为287844。

实验在亚得里亚海7处典型浅海潮下带岩礁生境开展。多数实验点位选自海洋保护区（Marine Protected Areas, MPAs）、自然公园或保护区，以及当前及未来保护规划覆盖的其他区域，旨在评估该流域现有及规划中的保护区网络的连通潜力。具体点位包括：特雷米蒂群岛海洋保护区（42°7'11.24"N - 15°29'2.25"E）、托雷瓜切托海洋保护区（40°42'59.46"N - 17°47'59.77"E）、欧盟特别保护区奥特兰托（40°7'13.53"N - 18°30'39.38"E）；克罗地亚：科尔纳蒂群岛国家公园（43°49'14.68"N - 15°14'5.37"E）；黑山：赫尔采格诺维（42°22'46.96"N - 18°34'49.96"E）；阿尔巴尼亚：卡拉布伦-萨赞国家公园（40°24'1.45"N - 19°18'52.99"E）；希腊：欧盟拟议的社区重要生境奥索伊岛（39°50'7.27"N - 19°23'29.86"E）。

针对每个点位，选取3个间距1-5公里、生境条件可比的随机样地，其底质类型、坡度及暴露程度均一致。在每个样地中，于水深5-7米的近水平岩质底面上随机选取6个方形样块（彼此间距数米，单块面积约2平方米），并通过螺丝与环氧腻子在四个角进行永久标记。其中3个样块被随机选取，通过移除基质上的原生生物群落进行实验性干扰处理：使用凿子与锤子刮除处理样块中的底栖表生生物群落，再用钢丝刷清除残留生物体。剩余3个样块保持原样，作为实验对照。

实验设置于2013年6月启动，所有点位的处理工作均在1个月内完成。固着生物群落在5个时间节点进行采样：实验初始阶段（2013年7-8月，仅针对未干扰样块）、干扰后3个月（2013年10-11月）、9个月（2014年4-5月）、12个月（2014年7-8月）及24个月（2015年7-8月）。每次采样时，使用配备频闪灯的水下数码相机，在每个样块中随机采集5张400平方厘米的摄影样本。最终共收集并分析2835份摄影样本，以鉴定底栖表生生物种类。

分析未涉及移动生物。共记录70个类群/组别，其中约80%可鉴定至物种或属水平。数据集记录了每个采样时间点下，各点位受干扰与未干扰群落的组成（存在/缺失情况）。