Abstract:
Based on the data collected from the oceanographic survey in the Ningde offshore area in August 2015 (119.867°E~120.649°E, 26.348°N~26.994°N), we analyzed the distribution characteristics of redox potential (Eh) of the surface sediments in the Ningde coast was in situ_measurement on deck in August 2015, and then analyzed those distribution characteristics.In addition, from the aspects of water mass properties, salinity, pH, dissolved oxygen of the feature parameters in overlying water and sulfide, organic matter, bottom matter type of the characteristics factor in sediments, we deeply studied the influencing factors of Eh.The results showed that the Eh value in the surface sediments varied from -162 mV to 110 mV with an average of -89 mV, which were basically in the weak reducibility and reducibility level.The distribution of Eh was higher in the coastal areas than the offshore areas.The Eh value decreased significantly compared to the results of Eh value in coastal areas in Fujian in 1980s.There is a certain correlation between the salinity, dissolved oxygen and other parameters of the overlying water and Eh values of the surface sediments, especially dissolved oxygen with an extremely significantly positive correlation (
r=0.729,
p < 0.01), and the spatial distribution are also similar.The sulfide content level of the surface sediments directly affected the Eh value, which showed an extremely significantly negative correlation (
r=-0.806,
p=0.000).In recent years, influenced by human activities, the redox status of surface sediments in the Ningde sea areas has changed significantly, which may threaten the biological activities in the sediment in some extent.Therefore, it is necessary to take some measures to strengthen the monitoring of submarine environment quality.At the same time of developing regional economy, we also need to further strengthen the efforts in protecting the marine environment.