Method of Model Assessments of Ecological Risk for Arctic Shelf Ecosystems of Different Productivity

摘要

The paper proposes a method for assessing the ecological risk, changing throughout the year with the natural functioning of marine ecosystems, and impact of various stressors. The method was applied to ecosystems contrast in productivity of the Arctic shelf. The paper analyses the features of the annual variability of phytoplankton biomass in the Barents, White, Chukchi, Kara, Laptev, and East Siberian seas for 1996-2018 based on the published materials of field research and estimates the annual risk variations for high- and low-productivity ecosystems with two and one annual maximum of phytoplankton biomass. Based on the obtained estimates, the probability of acceptable intensity of anthropogenic impact was calculated for three anthropogenic impact scenarios, with consideration of acceptable risks taken in the development of oil and gas resources on the shelf. The results revealed regions of safe impacts on the ecosystem, in which the type of impacts chosen in the experiment can be assumed with a probability of 80-100%, and regions of increased risk with the possibility of impacts less than 20-30%. We also obtained very close values of the risk and probability of acceptable impacts for high- and low-productive ecosystems of the Arctic shelf for a certain type and duration of impacts. This indicates that the determining risk factor in the proposed formulation of the problem is deviation of the average phytoplankton biomass from the average and critical values; i.e., when approaching the boundaries of stability, the risk increases. The proposed approach makes it possible to take into account the specifics of environmental safety issues in relation to asymmetric requirements for correcting type Ⅰ and Ⅱ errors.