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The results of studies on the content of aluminum and heavy metals in benthic sediments and algae in the estuaries of the Arctic island Vaygach are presented. This island is located on the Barents and Kara Sea border, and it is part of the Pay-Khoi ridge which can be called a "continuation" of the Ural Mountains to the north. The observations were conducted in Krasnaya and Varkulyakha Rivers located in the island's southern part and flow into the Yugorsky Shar Strait. Krasnaya River is located near a polymetallic ore deposit, which was developed in 1931–1934. Reconnaissance fieldwork was carried out in the river estuaries through measurements of salinity and water level. Measurements of the mass concentration of elements in the studied samples of sediments and algae were carried out by atomic emission spectrometry. The preparation of plant samples was by microwave decomposition, and that for samples of bottom sediments was carried out by acid decomposition in an open manner. The obtained concentration samples were compared using "Tukey exploratory data analysis (EDA)". The presence of anomalies in the high content of copper, manganese, and zinc in filamentous algae at the control site in the Krasnaya River estuary was revealed. For some elements, the enrichment index was calculated relative to the upper part of the earth's crust content. It is assumed that the occurrence of this situation is due to the long-term consequences of mining polymetallic ores. The accumulation of metals in river estuaries may be related to the observed warming of the climate in the western sector of the Arctic region. [ABSTRACT FROM AUTHOR]

This paper describes the distribution of plant communities from various associations, identified from the standpoint of the ecological-phytocenotic approach, occupying the tidal flat of low and medium marshes, which are under the influence of tide range, different values of pH and water salinity. According to the degree of pH influence, we identified acidotrophic, alkalotrophic, and indifferent phytocenoses, combined into different associations. Most associations of the estuaries with different tide range are alkalotrophic, there are noticeably fewer acidotrophic ones; a few eurytopic communities from the Phragmitetum australis, Bolboschoenetum maritimae, and Caricetum aquatilis associations are classified as indifferent. The study shows that the coastal vegetation of the marshes of the mesotidal estuaries of the White Sea develops in stable pH conditions in the range from 7.2 to 7.6. The formation of coastal vegetation is less stable in the macrotidal estuaries of the Mezen Bay, most of them form at pH = 7.0-8.3. Halophyte vegetation forms in the widest range of pH (6.2-8.3) in the marshes of microtidal estuaries in the Dvina Bay of the White Sea, which are more affected by floods than other estuaries. The halophytic vegetation of the White Sea develops in a wide range of salinity fluctuations from brackish to marine waters. However, the majority of plant associations in the rivers estuaries occupy the habitats of weakly saline waters with 10 to 25% salinity. [ABSTRACT FROM AUTHOR]