## 1 Introduction  
One of the most important aspects of rational nature management is the study of the state of the sea and ocean ecosystems [1]. North African deserts are an important source of mineral dust in the atmosphere [2]. This dust can be transported over thousands of kilometers to other continents and after deposition can affect oceanic and land biogeochemical cycles, even in very remote places. For example, the transport and subsequent deposition of African dust into the Amazon basin provide nutrients that make a significant contribution to the productivity of rainforests [3]. Recent decades have shown an increase in the frequency of dusty rains, including in northeastern Spain. [PERSON] et al. [4] noted that the intake of gases and suspended matter from the atmosphere associated with the air masses from the Sahara is an important source of nutrients for the Mediterranean Sea. The authors' studies show that even sporadic precipitation of this kind can affect the biological community (its diversity, activity, and quantity) over a certain period of time, and thus regulate the function of the microbial community and the carbon cycle in oligotrophic waters. In [5], articles were collected by different authors dedicated to the impact of dust from the Sahara on the ecosystem of the eastern Mediterranean. The deposition of atmospheric dust contributes to the input of macronutrients, such as phosphorus [6, 7, 8], nitrogen [9, 10, 11], iron [12, 13], and silicon [14] to the surface waters of the seas and oceans. [PERSON] and [PERSON] [6] argued that additional inorganic phosphorus input can reach up to 15% of \"new\"production and up to 14% of the total primary production in the upper mixed layer. Such input of phosphorus can contribute to the fixation of atmospheric nitrogen, which, in turn, can intensify the \"new\" primary production. In [15], the authors determined the effect of the input of phosphates with dust in the Mediterranean Sea. Their research results showed that primary production increased on average by 6-10%. However, the strongest influence was observed in the summer when the sea was in its most oligotrophic state: during the summer stratification, it increased up to 30% for several months. [PERSON] et al. argued that the effect of dust aerosols may be more significant in case of extreme precipitations. The paper also showed that nitrogen input, mainly associated with combustion processes, also has a great impact on the biological processes all over the sea. Silicon is one of the largest components of soil mineral aerosol. In recent decades, vigorous human activity has affected the natural cycle of silicon and its entry into the ocean [16; 17; 18]. In the coastal surface waters, this is especially distinct in changes in the concentrations of silicon, nitrogen, and phosphorus [19]. As a result, the stoichiometry of nutrients in the Black Sea has also changed: the Si:N ratio on the Danube shelf, for example, decreased tenfold [20], which created unfavorable conditions for the development of diatoms. [PERSON] [21] believed that about 10 Tmol (280 Tg) of suspended Si reaches the ocean surface due to the transport of aeolian dust, of which about 5-10% dissolve in the seawater, according to their rough estimates. Thus, transport of soil dust to the atmosphere is an effective way of redistributing Si in the environment. Taking into account the lack of silicon in the Black Sea, the atmospheric input of this nutrient with dust and atmospheric precipitation may have a positive effect on the development of phytoplankton. According to [22], the relationship between annual chlorophyll-A cycles and dust deposition could account for, on average, 11.5% of chlorophyll variability in most of the Mediterranean. At the same time, the eight-year analysis (2000-2007) of the SeaWIFS and BSC-DREAM8b model shows that the deposition of mineral dust from dust sources in the deserts of North Africa and the Middle East correlates well with the concentration of chlorophyll-A in large areas of the Mediterranean Sea.