Distribution of benthic foraminifera in surface sediments on the continental margin off North-West Africa

The benthic foraminiferal populations along three traverses across the Northwest African continental margin were analyzed on the base of ca. 60 surface sediment samples. Depth ranges of 213 species were established and the main trends of vertical distribution are compared with those known from adjacent regions. Main faunal breaks occure at 100/200 m and 1000/1500 m depth of water. Some species show latitudinal distribution boundaries and the same applies to population density (standing stock), reflecting the regional distribution of nutrients supply by river discharge and upwelling processes. – High proportions of Bolivina test at the lower slope indicate extended downslope transport.

基于约60个表层沉积物样本，对西北非大陆边缘三条横穿剖面沿线的底栖有孔虫种群展开了分析。研究确定了213个物种的深度分布范围，并将其垂直分布的主要趋势与邻近区域已知的趋势进行了对比。主要动物群分界出现在水深100/200米及1000/1500米处。部分物种存在纬度分布边界，种群密度（现存量，standing stock）亦呈现类似特征，这反映了河流输入与上升流过程所带来的营养物质的区域分布规律。——下陆坡区域Bolivina壳体的高占比表明存在广泛的下坡搬运过程。