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The Piip Volcano is a submarine volcanic edifice occupying the central part of the Volcanologists Massif in the southwestern Bering Sea, with two tops, southern and northern. The minimum depth of the northern top is located at 368 m, and of the southern at 464 m. Active hydrothermal venting occurring at both summits of the volcano supports diverse biological communities, including animals specific for chemosynthetic habitats. In benthic organisms inhabiting the northern and southern tops of the Piip Volcano, for the first time, we examined distribution patterns of the following trace elements: titanium, vanadium, chromium, manganese, iron, nickel, copper, zinc, arsenic, selenium, zirconium, molybdenum, silver, cadmium, antimony, barium, tungsten, lead, bismuth, and uranium. The element contents were quantified by the ICP-MS. Total carbon (TC) and total inorganic carbon (TIC) were determined using a Shimadzu TOC-L-CPN and mineral composition of sediment was determined using the XRD. In the water of the biotope from the northern top, concentrations of Mn, Zn, Ag, Cd, Sb, W, Pb were 2–6 times, and Ba was 50 times higher than those from the southern top. This was attributed to the lower temperature of fluids emanating at the southern top. An abundant population of Calyptogena pacifica (Bivalvia: Vesicomyidae: Pliocardiinae) was found only at the southern top. The main target of most trace elements, such as Fe, V, Cr, Co, Ni, Zn, As, Mo, Ag, Cd, W, Pb, Bi, and U were the soft parts of Calyptogena pacifica (with high TOC content, on average 53.1% in gills and 49.6% in the rest of the body). Gills were characterized by particular high contents (&gt, 100 µg g-1 dry w.) of Zn, Cd, Fe, Ni, Cu, and Pb, which can form sulphides or be associated with them. Shells of C. pacifica, as well as Brachiopoda, were depleted in these elements, as well as tissues of the carnivores Paguridae (Crustacea) and Actiniaria (Anthozoa). In suspension feeders from both tops, the lower contents of most elements were detected. Estimation of Biological Concentration Factor (BCF) for most elements varied from 102 to 104, reaching n105 for Ni, Zn, Ag, Ca, and Pb. A significant difference in BCF values between Fe and Mn was revealed.

The White Sea being connected with the Arctic Ocean via the Barents Sea has an influence on its water temperature/salinity structures and biological processes and thus has an indirect impact on the Eurasian climate system. In this work, we have managed to find a correspondence between the climate fluctuation in the Holocene and changes in the geochemical and microfossil properties in the sediment core of the White Sea. For the first time, the element speciation in the sediment core covering about 10,000 cal yr BP period was investigated. The cooling periods (the early Holocene and the Subboreal stage) were characterized by a trend of increase in Si, Al, and Ti contents and Ti/Al ratios, which reflect lithogenous contribution, and decrease in geochemically labile forms of trace elements. A significant increase in the content of organic-bound trace elements and biogenic components (Сorg, BSi, and chlorin) was observed during periods of Holocene climatic optimums. The evident relationship between the metal speciation and indicators of the sedimentation paleoenvironment is observed at the stage of the active phase of early diagenesis after the slowing down of the biogeochemical processes. Down-core decrease in the Mn oxyhydroxide content exhibited a weakening of diagenesis processes at the ~130–150 cm depth.

The concentration of trace elements (Fe, Mn, Cr, Co, Ni, Cu, Pb, Cd, As) through the planktonic food chain of the White Sea have been studied by the experimental approach. The experiment included zooplankton sampled in a reference area feeding on a seston contained the different trace metals concentrations. Seston sampled in the st. Chupa was enriched by Fe, Cu, Pb, Cr, Co, As, and Ni comparing to the seston from st. Kartesh (reference area). The differences in the concentrations of the suspended particular matter and of the indicator elements of a terrigenous admixture (Al, Ti, Zr) evidence on higher natural background of the trace metals’ content in the seston from st. Chupa due to higher contribution of the minerals. Zooplankton that fed on the seston characterised by higher trace elements’ content has accumulated Fe, Mn, and Cr, at a less degree, Ni, Co, Pb, and Cu; particularly, these were the elements which content were high in seston. Despite Mn content in seston did not differ between two treatments, this element was accumulated by the zooplankton, but had low content in faecal pellets. This tells about the highest Mn assimilation by the zooplankton; this element may become the most bioavailability. When comparing the trace element content between the seston and the faecal pellets, the concentrations of the most elements in faecal pellets are lower comprising as low as Zn – 72%; Mn – 24; Cu – 97; Pb – 62; Cr – 99; Co – 78; Ni – 87; As – 96; Cd – 65% of the concentration in the seston.

The concentration of trace elements (Fe, Mn, Cr, Co, Ni, Cu, Pb, Cd, and As) through the planktonic food chain of the White Sea have been studied with an experimental approach. The zooplankton sampled in the reference area fed on seston containing different concentrations of trace metals. Seston sampled at the Chupa station was enriched in Fe, Cu, Pb, Cr, Co, As, and Ni compared to seston sampled at Kartesh station (reference area). The differences in concentrations of the suspended particular matter and of elements indicating a terrigenous admixture (Al, Ti, Zr) are evidence of a higher natural background of trace metal content in seston from Chupa due to the higher contribution of the mineral component. Zooplankton that fed on seston characterized by a higher trace element content accumulated Fe, Mn, and Cr, and to a lesser degree, Ni, Co, Pb, and Cu; in particular, these were the elements with a high content in seston. Despite the absence of significant differences in the Mn content in the two groups of seston, its apparent accumulation by zooplankton and reduced content in fecal pellets are evidence of the highest digestibility of Mn by zooplankton, which can be associated with the bioavailability of Mn in the food source. When the content of trace metals in pellets and seston are compared, the fecal pellets of zooplankton are depleted in major elements, and their contents are (% of content in seston): Zn, 72%; Mn, 24; Cu, 97; Pb, 62; Cr, 99; Co, 78; Ni, 87; As, 96; and Cd, 65%.

The ability of bivalve mollusks to accumulate chemical elements from the environment makes them an important object for environmental monitoring and assessments of anthropogenic impact on marine ecosystems. The paper presents the data on the content of 65 chemical elements in soft tissues and shells of five species of bivalve mollusks (Astarte crenata, Ciliatocardium ciliatum, Portlandia arctica, Chlamys islandica, Hiatella arctica), as well as in the upper layer (0-5 cm) of bottom sediments of the Kara Sea, the Arctic Ocean. The content of major-, trace and rare-earth elements was determined by atomic emission and inductively coupled plasma mass spectrometry (ICP-AES; ICP-MS). The age, size, and weight of mollusks were measured. There were differences in the content of chemical elements accumulated in soft tissues and shells of mollusks, as well as the significant interspecific difference in the chemical composition of the studied mollusks. The soft tissues of mollusks were accumulated with toxic metals (Hg, Ag, and Cd) in comparison with the content of these elements in bottom sediments. In Chlamys islandica and Hiatella arctica, the shell was accumulated in Cd in contrast to other species. The data obtained may be used for a comprehensive assessment of the state of ecosystems in the seas of the Siberian sector of the Arctic Ocean under changing environment and for studying the fundamental base of the accumulation of chemical elements by marine organisms.

A comprehensive examination of the elemental (including radionuclides and heavy metals), mineral, and grain-size composition of sediments from different areas of the Barents Sea was performed. Sediment cores were sampled in the Central Deep, Cambridge Strait (Franz Josef Land Archipelago), Russkaya Gavan&rsquo, Bay (Novaya Zemlya Archipelago), and Bear Island Trough. We aim to evaluate how the modern and more ancient environmental conditions are reflected in the elemental and mineral composition, as well as to test indicative elemental ratios. The applied methods include elemental analysis using gamma-ray spectroscopy, X-ray fluorescence (XRF), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and X-Ray Difractometry XRD analysis of minerals. Difference in sedimentation rates, grain-size composition, and sources of material, are reflected in downcore variation of Si/Al, Mn/Fe, P/Al, Ti/K, and quartz-feldspar ratios. At boundary Early Holocene/Late Deglaciation, intensive bottom currents from the West-Southern shelf areas contributed to increase of Si/Al and Zr/Ca ratios. Distinct growth of the Si/Fe ratio within the sediments deposited over Late Pleistocene to Mid Holocene may be caused by increased contents of the coarse sand material, as well as by abundant fluxes of clay-mineral-loaded glacial meltwater during the main deglaciation phase. The Mn/Fe ratio used as redox proxy, displayed peaks at different depths related to oxygen concentration growth in bottom water.

The contribution of different geochemical processes in the accumulation of metals in dispersed sedimentary matter collected by ADOO was estimated for the first time for the White Sea system. The contents of Al, Fe, Cr, Ni, Со, and Мо (from 60 to 90% of the total content) are mainly controlled by terrigenous processes. The group of geochemically mobile elements includes Mn, Cu, Pb, and Cd; the sum of their forms 1–3, which include the contribution of absorption−desorption and formation of authigenic hydroxides and organic compounds, accounts for, on average, from 52 to 83 Mn %. With increasing water depth, the fraction of the lithogenic form remains either constant or increases insignificantly. In contrast, Mn shows a sharp increase in geochemically mobile forms, heavy metals (Pb, Cu, Mo, Co, and Cd) of which are associated with.

For the first time based on determination of the geochemical occurrence forms of trace metals the main processes that control the accumulation of elements (Al, Mn, Fe, Mo, Cr, Ni, Co, Cu, Pb, Cd, and As) in the recent sediment cores from the White Sea and Barents Sea were quantified. A high-resolution study of the bottom sediment cores allowed us to estimate the short-term variations (periodicity of 10–15 years) in the accumulation of metals to reveal the periods of maximum Fe and Mn contents in the amorphous hydroxides fraction, which serve as effective adsorbents of the trace elements majority, including heavy metals. The Mn/Fe ratio in the amorphous hydroxides phase can be considered as geochemical indicators of early diagenesis.

In this study, to better understand the influence of hydrothermal processes on ore metal accumulation in bottom sediments, we examined distribution of Fe, Mn, Cu, Zn, As, and Pb in core of metalliferous sediments from the Pobeda hydrothermal cluster, and in core of non-mineralized (background) carbonate sediments (located 69 km northwards). Mechanisms of Fe, Mn, Cu, and Zn accumulation in sediments (12 samples) were evaluated based on sequential extraction of geochemical fractions, including a conditional mobile (F-1, exchangeable complex, F-2, authigenic Fe-Mn oxyhydroxides and associated metals, F-3, metals bound to organic matter/sulfides), and residual (F-4), fixed in crystalline lattices ones. The element contents were determined by the XRF and AAS methods, total carbon (TC) and total organic carbon (TOC) were determined using a Shimadzu TOC-L-CPN. Mineral composition and maps of element distribution in sediment components were obtained using the XRD and SEM-micro-X-ray spectrometry methods, respectively. In metalliferous sediments, according to our data, the major Fe mineral phase was goethite FeOOH (37–44% on a carbonate-free basis, cfb). In the metalliferous core, average contents (cfb), of Fe and Mn were 32.1% and 0.29%, whereas those of Cu, Zn, Pb, and As, were 0.74%, 0.27%, 0.03%, and 0.02%, respectively. Metalliferous sediments are enriched in Fe, Cu, Zn, Pb, and As, relatively to background ones. The exception was Mn, for which no increased accumulation in metalliferous core was recorded. Essential mass of Fe (up to 70% of total content) was represented by the residual fraction composed of crystallized goethite, aluminosilicates, the minerals derived from bedrock destruction processes mineral debris. Among geochemically mobile fractions, to 80% Fe of the (F-1 + F-2 + F-3) sum was determined in the form of F-2, authigenic oxyhydroxides. The same fraction was a predominant host for Mn in both metalliferous and background sediments (to 85%). With these Fe and Mn fractions, a major portion of Cu, Zn, and Pb was associated, while a less their amount was found in sulfide/organic fraction. In the metalliferous sediment core, maximal concentrations of metals and their geochemically mobile fractions were recorded in the deeper core sediment layers, an observation that might be attributed to influence of hydrothermal diffused fluids. Our data suggested that ore metals are mostly accumulated in sediment cores in their contact zone with the underlying serpentinized peridotites.

The White Sea is an inner subarctic marine basin where sedimentation is known to be influenced by mostly terrigenous processes. In the catchment area of the White Sea, a lot of the mining, manufacture, and pulp and paper industry plants are located whose solid and liquid wastes contain heavy metals, including the toxic ones. Through the solid and dissolved river runoff, atmospheric fluxes, and coastal abrasion, heavy metals enter the seawater where they are involved in various biogeochemical processes before to be precipitated on the sea floor. Many studies of marine sedimentation concern total metal concentration; meanwhile, an assessment of contribution of different biogeochemical processes stays incomplete. In this chapter, we try to evaluate the partitioning among the different forms (speciation) of heavy metals that reflect principal processes of their accumulation in the modern bottom sediments of the White Sea. We study both the rock-forming (Al, Fe, Mn) and trace elements (Mo, Cr, Ni, Co, Cu, Pb, Cd, and As) by use of a modified method of selective sequential chemical leaching.