Characteristics of different forms of nitrogen and phosphorus and organic carbon in the sediments of low-oxygen zones in adjacent Rushan Bay
乳山湾外低氧海域沉积物中有机碳、氮、磷及其形态特征分析

A comprehensive survey of Rushan Bay and its adjacent area was carried out in August, 2009. The content and forms of organic carbon, nitrogen and phosphorus in surface sediments were analyzed. Fine sediment is the major components of the sediment in this area. The contents of organic carbon, total nitrogen and phosphorus in the marine sediments range from 0.49% to 0.93%, from 382 to 1020 mg/kg and from 138 to 769 mg/kg, with their average value of 0.69%, 671 mg/kg and 356 mg/kg, respectively. In addition, dissolved organic and ammonia nitrogen account for 58.8% and 38.8% of the total dissolved nitrogen. The organic phosphorus is the dominant part of the total phosphorus (62.5%). The concentration of total nitrogen is equal to that in Rushan Bay. The organic carbon and phosphorus concentrations are lower than those in Rushan Bay, but higher than those in the South Yellow Sea. The relatively high content of organic carbon, nitrogen and phosphorus in the sediments might due to the material exchange between Rushan Bay and the open seas. The sediment oxygen consumption may be the major cause of loss of dissolved oxygen in the bottom water, which needs further research.