Biotransformation of Organogenic Substances in the Aniva Bay Waters: Assessment with the Use of Mathematical Modeling

Abstract

Mathematical modeling is used to study the conditions of natural biotransformation of biogenic element compounds (containing C, N, P, Si) in five areas within Aniva Bay. The input data for the model are evaluated with the use of GIS "Sakhalin Shelf" and the available reference literature on the bay oceanography. Water masses that transferred through the boundaries between the areas were evaluated based on the values of water level, river runoff, atmospheric precipitation, evaporation, and the volume of water in the bay, all of which vary as a result of water heating. The model was used to evaluate annual variations in the concentrations of organic and mineral fractions of these elements and the biomasses of planktonic organisms for the five areas in the bay. Modeling results also allowed the assessment of biogenic substance input with river runoff into Lososei Bay. Based on the internal fluxes of substances, the monthly and annual aquatic animal production was evaluated.

Assessment of the Hydrochemical Characteristics of the Carbon Observational Site ‘Carbon-Sakhalin’ (Aniva Bay, Sea of Okhotsk)

“…However, these data provide only partial information on the HCh regime in Aniva Bay. The characteristics of Aniva Bay obtained from this application were used as input parameters for the modeling of hydrological, HCh parameters, and transformation of petroleum hydrocarbons in the bay [43,[69][70][71][72].…”

Analysis of Conditions of Petroleum Hydrocarbon Transformations in Seawater and Simulation of This Process in Aniva Bay

“…The use of the input data characterizing the oceanographic regime of Aniva Bay is described in detail in [10]. Unfortunately, no adequate data on the input, concentration, and distribution of PHC in the bay water area are available.…”

“…The pollution of this area by biogenic element compounds and PHC is mostly due to river runoff. The characteristics of river runoff used in this study refer to high-water regime [10]. The concentration of PHC in river water, which determines the anthropogenic load on the marine environment of the bay (1 to 2 MPC for January-March, 5 to 6 MPC for April-May, and 4 MPC for June-December) takes into account the increased pollution of river water in accordance with the published data [23,24,37]; Areas 2, 3, and 5.…”

“…The model period covered a calendar year (January 1 to December 31), and the calculations were based on the estimated mean annual characteristics of the state of aquatic environment (temperature, light intensity, water transparency, water exchange regime between areas 1-5) [10].…”