Ecosystem Health Assessment for Bay Based on Index System in Laizhou Bay

Abstract

The bay ecosystem plays an important role in maintaining energy flow, material circulation, community stability and ecosystem balance. In the present study, the comprehensive evaluation model for marine ecosystem of Laizhou Bay was established by using index system method, in which, five indicators were selected including water environment, sedimentary environment, marine community, primary productivity and ecological disaster indexes. The relative importance and weight of the evaluation indexes were determined combined using analytic hierarchy process and experts consultation method. By analyzing the survey data obtained, this assessment system was applied to assess and compare the health level of Laizhou Bay in recent ten years. Results showed that the condition of Laizhou Bay was always being sub-health, the main indicators that had given adverse impact on the health level of Laizhou Bay included inorganic nitrogen, phosphate, petroleum hydrocarbon, plankton species and benthic biomass. The results of evaluation model were more sensitive to Laizhou Bay, which could identify the adverse effects of extreme events such as oil spills and typhoons, therefore, the use of interval index and environmental admissible value could avoid disadvantage concealment, information omissions and the overestimation of limit value-based assessment method effectively.

Keywords

• marine ecosystem
• health assessment
• index system method
• laizhou bay