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.

本数据集提供了一幅栅格图层（格式为.img），展示了地中海西北部克雷乌斯角（Cap de Creus）外大陆架与海底峡谷中柳珊瑚*Eunicella cavolini*（Koch, 1887）的预测分布范围。该区域属于Natura 2000网络的社区重要性位点（Site of Community Importance, SCI）。研究基于60条水下视频样带（水深80至400米）提取的物种密度数据，结合地貌学、海洋学与人为属性的一系列环境因子，采用随机森林（Random Forest, RF）算法构建了适宜该物种栖息的生境预测模型。该模型预测，在整个模拟区域内，1061公顷的海域存在该物种（群体密度不低于1个·平方米⁻²），其中14公顷海域的柳珊瑚群体密度可能超过5个·平方米⁻²，另有4.9公顷海域的群体密度超过10个·平方米⁻²。模型可解释的变异度为70.1%，但交叉验证评估显示实际解释的变异度或更低，表明水下调查样带的数据存在一定程度的空间自相关性。基于预测模型的均方误差平均增幅分析，研究区域内影响*E. cavolini*高密度斑块出现概率的关键变量依次为底层平均流速、水深以及海底粗糙度（通过地形粗糙度指数Terrain Ruggedness Index, TRI计算得到）。本研究为地中海西北部新近划定的海洋保护区内*E. cavolini*的空间分布提供了关键信息，可供政策制定者在该SCI区域内制定该物种的专属保护管理措施时参考。
本数据集关联的学术论文为Dominguez-Carrió等人提交至《Estuarine, Coastal and Shelf Science》的"Environmental niche, spatial distribution and size structure of shelf-dwelling populations of the gorgonian Eunicella cavolini (Koch, 1887) in NW Mediterranean"，该论文详细记载了数据的获取与处理流程。