Evaluation of the Natural Fishery Resources Loss Caused by an Oil Spill Accident in the Central Bohai Sea Based on Euler-Lagrange Method

Abstract:

In recent years, marine oil spill accidents occurred frequently, which has become a major concern on the marine environment and biological resources. To better understand the aftermath of an oil spill in a ship collision accident in the central Bohai Sea, here we modeled the floating and diffusion of oil film as well as the distribution of dissolved oil (petroleum hydrocarbon) using Euler-Lagrange method. The size of affected area and loss of fishery resources were also evaluated based on this model. We found that the volume of spilled oil was about 13,000 L, and the oil film lasted for 72 hours. The sea area affected by accumulated floating oil was about 69.19 km2. As the film broke down, oil droplets could be dissolved in the seawater in the form of emulsified and suspended particulate, and diffused to the coastal in 11 days, although the water quality would still meet the standard for fisheries. The oil film resulted in reduced fisheries resources, and the emulsified and suspended particulate could re-condense at the coast, which would harm the intertidal benthos. The affected area was determined based on the model and the length of coastline. It was estimated that the total economic loss in the oil film zone and the intertidal coastal zone was ¥ 6.319 million. Our study demonstrated that the numerical model, especially in the absence of observed data, could be a valuable tool in evaluating the change in natural fishery resources caused by oil spill accidents.