Risk assessment simulation for shelf ecosystems based on the ecoscreening and dynamic methods synthesis

Abstract

The paper simulates ecological risk assessment for shelf ecosystems based on the ecoscreening and dynamic methods synthesis. Both approaches and environmental risk model are described, which results make it possible to estimate probability of acceptable impact on the shelf ecosystem. In contrast to existing approaches related to ranking and compiling risk matrices, the proposed method based on probabilistic ecoscreening risk assessment takes into account not only the altering conditions of external influence on the shelf ecosystem, but also the intra-annual dynamics of its main components. This makes it possible to calculate the ecological risk not as a fixed value for the ecosystem under study, but as its component changing over the course of a year along with the intra-annual functioning dynamics. The latter is especially important for the coastal basins, where processes of various genesis are concentrated, high gradients of biomass values and concentrations of components containing it are presented. To simulate various scenarios of combining the effect of external stressors with the intra-annual dynamics of the ecosystem functioning, the Northern Caspian shelf basin was selected, which is subject to intense river flow and to exposure to mineral resources development technologies, including oil and gas. Ecological risk values were calculated taking into account combination of adverse natural factors and implementation of emergency and regular anthropogenic impacts at different periods of the shelf ecosystem components natural dynamics. Results made it possible to assess probabilities of the allowable exposure of shelf ecosystem, to identify areas with the 100% probability of allowable impact and especially critical areas with less than 5% of the impact probability. Calculations show not only efficiency of the proposed approach, but also open possibility of harmonizing ecological and economic requirements in the development of shelf resources. For areas with high allowable impact probability, it is possible to reduce the economic costs of ensuring ecological safety. Ecological risk areas, which are characterized by low estimate of allowable impact probability require an increase in the safety economic expenses. The proposed approach to estimating the intra-annual risk dynamics is of interdisciplinary nature and could be useful both to specialists in the ecology area, in the related fields, and to management personnel in making decisions on redistributing economic expenses and minimizing them while maintaining the priority of environmental safety.