Remote Sensing-Based Study on the Temporal Variations in Chlorophyll-a Concentration After Confo Oil Spill in Bohai Sea

Abstract

The satellite-derived chlorophyll-a concentration was used to measure the impact of oil contamination on marine environment after the oil spill on June 4, 2011 in the Bohai Sea. The chlorophyll-a concentration and sea surface temperature was derived from MODIS images with 38.47 % and 7.63 % uncertainty, respectively. The impacts of oil spill on aquatic environments can be divided into three stages: (1) the beginning stage (0–7 weeks), during which the toxicity of other pollutants besides the oil exceeds the tolerance of most algae in the Bohai Sea; (2) the self-repairing stage (7–51 weeks), during which the petroleum hydrocarbon concentration is diluted by the physical and chemical degradation process of aquatic ecology and petroleum hydrocarbon becomes one an important carbon source for algal growth; and (3) long-term toxic affecting stage (>1 year). However, there is currently little knowledge about the long-term toxic effect of oil spill on the natural assemblages of marine phytoplankton. In this study, we determined that the process for delivering nutrients required for algal growth from seabed to water column is slowed by the ‘oil-packaged’ suspended particles above the seabed. These results may be helpful for oil spill response, ecological remediation, and environment monitoring.