Analysis of the effects of wet and dry seasons on a Mediterranean river basin: consequences for coastal waters and its quality management

摘要: Abstract Rivers play a major role in the delivery of nutrients to coastal ecosystems which are essential for ecosystem productivity. However, increase due anthropogenic activities can cause eutrophication problems. This study analyzes seasonal variation phytoplankton communities receiving waters Mediterranean river. Two scenarios compared: wet and dry season with distinctive characteristics. During agricultural runoff combined sewer overflows (CSO) were responsible nutrient discharges, while during partially treated effluent from wastewater was main source. In waters, diatoms typical cycle modified by CSO discharges rain episodes, dinoflagellate abundance higher effluents low turbulence. We recommend that design Water Framework Directive monitoring programs should take into account treatment plants systems located near coast. Management decisions only reductions summer likely be efficient short term. Analyzing corrective measures cost through cost–benefit analysis would help determine whether costs excessive or not.