Abstract. Based on the investigation data on Cu in surface and bottom waters in the bay mouth of Jiaozhou Bay in 1983, this paper analyzed the seasonal variations, vertical variations and horizontal distributions of Cu. Cu contents in surface waters in the bay mouth of Jiaozhou Bay in May, September and October 1983 were ranged from 2.47-20.60 μg L -1 , 1.28-4.86 μg L -1 and 0.77-2.28 μg L -1 , and were in order of spring > summer >autumn; while for bottom waters were ranged from 0.86-3.95 μg L -1 , 1.31-1.90 μg L -1 and 0.24-2.00 μg L -1 , and were in order of spring >autumn >summer. The horizontal distributions of Cu in surface and bottom waters were consistent in May and October, while in September were reverse. At Spatial scale, Cu contents in both surface and bottom waters were tending to be decreasing. Once the input of the sources were stop, Cu contents in surface waters were increasing, yet in bottom waters were still decreasing. As time pass by, Cu contents in bottom waters were increasing along with the increasing of Cu contents in surface waters.
IntroductionCu pollution is one of the world wide environmental issues due to the excess cupric ions is harmful to marine ecosystem and finally to human health. Jiaozhou Bay is a semi-closed bay located in the south of Shandong Peninsula, eastern China. Previous studies showed that this bay had been polluted by Cu [1-2]. Hence, it is necessary to understand the vertical distributions and seasonal variations of Cu. This paper analyzed the seasonal variations, spatial distributions of Cu based on the investigation data on Cu in both surface and bottom waters in the bay mouth of Jiaozhou Bay. The aim of this paper was to provide basis for vertical sedimentation process and horizontal transfer process of Cu, which were essential to pollution control and environmental remediation.
Materials and methodJiaozhou Bay (35°55′-36°18′ N, 120°04′-120°23′ E) is located in the south of Shandong Peninsula, eastern China. The area and and average water depth are 460 km 2 and 7 m, respectively, yet the bay mouth is only 2.5 km (Fig. 1). This bay is surrounding by cities of Qingdao, Jiaozhou and Jiaonan in the east, north and south, and is connected with the Yellow Sea in the south. There are more than ten inflow rivers such as Loushan River, Licun River and Haibo River, all of which are seasonal rivers [3][4]. , respectively, and were ranged from 0.24-3.95 μg L -1 in the whole year. Cu contents in surface waters were in order of spring >autumn >summer.The major sources of Cu in spring in Jiaozhou Bay were overland runoff, stream flow, and marine current. The source strengths of the marine current were relative high in spring, so the Cu contents in surface waters were highest in spring. Overland runoff and stream flow were the major Cu sources in summer, yet the source strengths were relative low, hence the Cu contents in summer in surface waters were relative low. Stream flow were the major Cu sources in autumn, yet the source strengths were relative low, hence the Cu content...
