Ecological risk modelling in developing resources of ecosystems characterized by varying vulnerability levels

This paper proposes a method for mathematical modeling and ecological risk assessment in marine ecosystems under the combined action of natural, anthropogenic, climatic and invasive factors. The method is based on the combined use of dynamic models, probabilistic eco-screening risk assessments and observational data (EERO). Main advantage of the proposed approach in comparing with the already known methods lies in modeling the stressors effect on the ecosystem main components intra-annual functioning mode. This allows obtaining the ecological risk intra-annual variations, identifying the intra-year intervals of increased danger and calculating the corresponding acceptable probability of anthropogenic impact. Risk simulation examples in regard to the temperate latitude regions (Northern Caspian) highly productive ecosystems and to the Arctic area low productive ecosystems are provided. Results obtained brought to nontrivial conclusions on the ecosystems vulnerability and on the necessity to prioritize ecological risk calculation followed by assessment of the allowable exposure probability. In the environmental and economic aspect, the use of EERO would help to minimize economic expenses in the development of shelf resources. Calculation of the intra-annual ecological risk variations and the corresponding calculation of the anthropogenic impact allowable probability would make it possible to vary expenses on the ecological protection measures. The volume of such measures would be determined by increasing or decreasing requirements to the acceptable anthropogenic load calculated in accordance with the model. The paper substantiates the primacy nature of determining the acceptable ecological risk value and further the acceptable intensity of anthropogenic impact that opens a possibility to receive answers to questions on the basic acceptability of accidents of a certain scale. The method is efficient in assessing the risk to ecosystems with varying degrees of vulnerability. The proposed approach is important for practical coordination of ecological and economic requirements in safe development of shelf resources and in costs minimizing.