In order to reconstruct the environmental evolution of the Deba and Urola estuaries located in the Basque Coast Geopark at millennial, centennial and decadal timescales, four long boreholes, three short cores and twelve surface samples were studied. Multiproxy analysis (foraminifera, trace metals and radioisotopes) shows the temporal transformation of these estuaries in response to regional driving forces such as fresh-water discharge, relative sea-level (RSL) variation and the more recent impact of industrial development. At millennial and centennial timescales, the Deba estuary transformed from a tide-dominated to a river-dominated estuary at about 8000 yr cal BP following the decrease in RSL rise rate. This decrease also led to a reduction in both salinity and marine influence in the nearby tide-dominated Urola estuary. At decadal timescale, human disturbance on foraminiferal populations was found to be lower in the Deba estuary despite its higher level of contaminants in sediments. This was due to the greater impact of fresh-water discharge. In the Urola estuary, dredging operations altered severely the foraminiferal biota.

为了重建位于巴斯克海岸地质公园的Deba和Urola河口的千年，百年和十年尺度的环境演变，研究了四个长钻孔，三个短岩心和十二个地表样品。多代理分析（有孔虫，痕量金属和放射性同位素）显示，这些河口随区域驱动力（如淡水排放，相对海平面（RSL）变化以及工业发展的最新影响）而随时间变化。在千禧年和百年时间尺度上，随着RSL上升速率的降低，Deba河口从潮汐为主的河口转变为河水为主的河口（大约8000年cal BP）。这种减少还导致附近潮汐主导的Urola河口的盐度和海洋影响力降低。在十年的时间尺度上，在底巴河口发现有孔虫种群的人为干扰较少，尽管沉积物中的污染物含量较高。这是由于淡水排放的影响更大。在Urola河口，疏dr作业严重改变了有孔虫的生物区系。