Seabird monitoring spread

This data set contains information on the population density of seabirds in the German offshore areas based on a 10x10 km grid (EU-GRID). The density [individuals/km²] is determined for each grid cell by adding the individual number of counting points within the respective grid cell and dividing it by the sum of the effort at the counting points. Individual layers show bottom by season (March — May: Spring; June — August: Summer; September — November: Autumn; December — February: Winter) the distribution of seabirds in the respective year. In addition to seabird density, the density of the sighted juveniles is also determined. The surveys are carried out by the umbrella association of German Avifaunists (DDA). A more detailed description of the methodology can be found in the monitoring reports of the BfN (https://www.bfn.de/wirbeltiere).本数据集基于10×10千米网格（EU-GRID），收录德国近海区域的海鸟种群密度相关信息。每一个网格单元的密度（单位：个体/平方千米）计算方式为：将对应网格单元内所有计数点的个体总数求和，再除以该些计数点的总观测投入量。各图层按季节（3—5月为春季；6—8月为夏季；9—11月为秋季；12—2月为冬季）展示对应年份的海鸟分布情况。除海鸟种群密度外，本数据集还同步统计并计算了观测到的幼鸟密度。本调查由德国鸟类学家联合总会（DDA）统筹开展。有关调查方法的详细说明可参阅德国联邦自然保护局（BfN）的监测报告（https://www.bfn.de/wirbeltiere）。