Nitrogen and metal pollution in the southern Caspian Sea: a multiple approach to bioassessment.

摘要: The Caspian Sea hosts areas of high ecological value as well industrial, leisure, and agricultural activities that dump into the water body different kinds pollutants. In this complex context, a proper description origin potential sources pollution is necessary to address management mitigation actions aimed at preserving quality resource integrity ecosystems. Here, we detecting both nitrogen inputs, by N stable isotope analysis macroalgae, metals in macroalgae sediments two highly anthropized coastal stretches Iranian side Sea. Sampling was done near mouth rivers canals draining urbanized areas. westernmost waters, facing port city, low macroalgal δ15N signatures indicated industrial fertilizers principal source pollution. By contrast, central touristic areas, inputs from wastewaters. Here lowest dissolved oxygen concentrations waters were associated with excess inorganic nitrogen. Metal varied largely study lower than sediments. Localized peaks Pb Zn observed sites probable byproducts mining activity transported downstream. Cr Ni all sampling sites, thus potentially representing hazardous elements for marine biota. Overall, coupled metal useful identifying main these This double approach comprehensive monitoring programs could effectively inform stakeholders on major environmental threats, allowing targeted measures.