Modelled distribution of the gorgonian Eunicella cavolini in Cap de Creus continental shelf and submarine canyon (NW Mediterranean)

this dataset provides a raster layer (.img format) with the predicted distribution of the gorgonian eunicella cavolini (koch, 1887) on the continental shelf and submarine canyon off cap de creus (nw mediterranean), an area included in a site of community importance (sci) of the natura 2000 network. the algorithm random forest (rf) was used to model areas suitable for the development of the species based on a combination of species density data extracted from 60 underwater video transects (80 to 400 m depth) and a set of environmental factors of a geomorphologic, oceanographic and human nature. the rf model predicted the presence of the species (densities of at least 1 col·m-2) in 1,061 ha along the whole modelled area, with 14 ha potentially hosting gorgonian densities above 5 col·m-2 and 4.9 ha with densities exceeding 10 col·m-2. the variability explained by the model was 70.1%, although a cross-validation assessment indicated that the variability explained could be lower, denoting some degree of spatial autocorrelation of the data within the underwater dives. based on the percentage increase in mean squared error of the model used for predictions, the most important variables determining the likelihood of finding high-density patches of e. cavolini in the study area were average bottom current velocity, depth and rugosity of the seafloor (calculated as tri, terrain ruggedness index). this study provides relevant information about the spatial distribution of e. cavolini inside a recently declared marine protected area of nw mediterranean, which could be used by policymakers when formulating specific management measures for the conservation of this species within the sci.this dataset is related to the article “environmental niche, spatial distribution and size structure of shelf-dwelling populations of the gorgonian eunicella cavolini (koch, 1887) in nw mediterranean” submitted to estuarine, coastal and shelf science by dominguez-carrió et al., which contains further information on how the data were obtained and processed.

本数据集提供了一层栅格数据（.img格式），用以预测地中海东北部大陆架及海底峡谷地区（位于卡德罗斯角附近）的柳珊瑚 Eunicella cavolini（Koch, 1887）的分布情况。该区域被纳入Natura 2000网络中的社区重要性（SCI）地点。本数据集基于60条水下视频剖面（深度在80至400米之间）提取的物种密度数据以及一系列地形、海洋学及人类活动因素，运用随机森林（Random Forest，简称RF）算法构建了该物种适宜生长区域的模型。RF模型预测在整个模型区域中，有1,061公顷范围内存在该物种（密度至少为1 col·m-2），其中14公顷可能拥有密度超过5 col·m-2的柳珊瑚，4.9公顷的密度超过10 col·m-2。模型解释的变异性达到70.1%，然而，交叉验证评估显示，解释的变异性可能更低，这表明水下探险数据存在一定程度的空间自相关性。根据用于预测的模型平均均方误差的百分比增加，决定研究区域内E. cavolini高密度斑块出现可能性的最重要变量为平均海底流速、深度以及海底的粗糙度（以地形粗糙度指数TRI计算）。本研究为地中海西北部近期宣布建立的海洋保护区内的E. cavolini空间分布提供了相关资料，这些资料可供政策制定者在制定该物种在SCI内的特定保护措施时参考。本数据集与Dominguez-Carrío等人提交至《河口、海岸及大陆架科学》杂志的论文“地中海西北部栖息地、空间分布及大小结构：大陆架栖息的柳珊瑚Eunicella cavolini（Koch, 1887）”相关，该论文包含了关于数据获取和处理的进一步信息。