Element composition of several marine macrophytes (Crimea, Black Sea) and correlations with the element abundances in sediments and seawater.

The study of the element accumulation in marine plants against the backdrop of permanently increasing environmental pollution is of particular importance due to the participation of these plants in biogeochemical cycles. The element abundances are highly variable and depend on both the macrophyte species and environment. The purpose of this study was to analyze the elemental composition of widespread marine plants of different taxonomic affiliations collected in the same area of the Black Sea coast. The contents of 74 elements in three species of lower (red, brown, green algae) and one species of higher plants (seagrass) were analyzed using inductively coupled plasma mass spectrometry. High contents of most elements were found in the red alga Ceramium ciliatum and in rhizomes of the seagrass Zostera noltei. In C. ciliatum, high metal bioaccumulation factors were found, which are dependent also on their concentration in the environment. Compared to the higher plant, all the macroalgae accumulated increased amounts of As and I. The seagrass proved to be a good concentrator of Mo and Sb, and relatively high contents of Mn, Co, Ni, Zn, Cd and Ir were registered in its leaves. High contents of Mg, S, Ge, Se and Ta were found in the green alga Ulva rigida, and elevated levels of Al, As, Sr, Zr, Ru, Rh, Pd, Ag, Ba and Re were noted in the brown alga Gongolaria barbata. The enrichment factors for most elements in the sediments were well above 1 with respect to both the local Late Pleistocene sediments and the upper continental crust. The strength of correlations between the element contents in the plants and sediments was found to decrease with the specific surface area growth and appeared to have a lower asymptotic limit of the sediments-seawater correlation strength.

Rare earth elements in different body parts of the mussel Mytilus galloprovincialis (Crimea, Black Sea) and assessment of associated human health risks from its consumption.

The rare earth element (REE) pollution in the hydrosphere has become a matter of serious concern lately. In this study, using inductively coupled plasma mass spectrometry, the REE contents in soft tissue, byssus and shell liquor of the mussel Mytilus galloprovincialis, as a potential REE pollution bioindicator, in the Black Sea were determined for the first time. The highest REE levels were observed in mussels from the seabed. The REE contents in byssus and shell liquor were higher than in soft tissue. In byssus, the contents of Y, La, Ce, Nd and Dy were the highest, whereas in shell liquor, the heavier REE and Sc were the most concentrated. No likely REE-associated risks from the mussel meat consumption were detected. In soft tissue and byssus, REE contents significantly correlated with that of silicon.

Elements in Soft Tissues of the Young Mediterranean Mussel Mytilus galloprovincialis Lam. 1819 Collected in Sevastopol Bay (Crimea, Black Sea): Effects of Age, Sex, Location, and Principal Morphometric Parameters.

Although the mussel Mytilus galloprovincialis has been known for decades as an excellent bioindicator of trace element pollution in the marine environment, there is still no information on the effects of a suite of its principal morphometric parameters and age on trace element levels in soft tissues. In this work, using inductively coupled plasma mass spectrometry, we studied the contents of 72 elements in soft tissues of M. galloprovincialis aged 0.5-4, which were sampled at three stations within a relatively small water body, Sevastopol Bay. Significant effects of age and sampling location on the element contents and soft tissue dry-to-wet weight ratio were discovered. The effects of sex were not significant. It was presumed for the first time that the decrease in element content in the soft tissues of young mussels can be associated with the decrease in physiological needs for elevated contents of essential elements and intracellular water with age. Combinations of six principal morphometric parameters showed that a function of as few as three parameters (soft tissue dry weight, whole mollusk weight, and shell height, with by far the greatest contribution of the dry-to-total weight ratio) formed significant correlations with the contents of the largest possible number of elements (69-88% of the total number). For the first time, it was shown that linear discriminant analysis and canonical analysis of principal coordinates can be successfully used for tracing the exact origin of mussel samples within such a small water area. Canonical analysis of principal coordinates proved superior in the correct classification of the samples.

The mussel Mytilus galloprovincialis (Crimea, Black Sea) as a source of essential trace elements in human nutrition.

Micronutrients, or essential trace elements, are important components in various metabolic processes inherent to the normal functioning of organism. To date, a substantial part of the world population suffers from a lack of micronutrients in the diet. Mussels are an important and cheap source of nutrients, which can be utilized to mitigate the micronutrient deficiency in the world. In the present work, using inductively coupled plasma mass spectrometry, the contents of the micronutrients Cr, Fe, Cu, Zn, Se, I, and Mo were studied for the first time in soft tissues, shell liquor, and byssus of females and males of the mussel Mytilus galloprovincialis as the promising sources of essential elements in the human diet. Fe, Zn, and I were the most abundant micronutrients in the three body parts. Significant sex-related differences in the body parts were detected only for Fe, which was more abundant in byssus of males, and Zn, which exhibited higher levels in shell liquor of females. Significant tissue-related differences were registered in the contents of all the elements under study. M. galloprovincialis meat was characterized as the optimal source of I and Se for covering the daily human needs. Regardless of sex, byssus turned out to be richer in Fe, I, Cu, Cr, and Mo in comparison with soft tissues, which fact allows recommending this body part for the preparation of dietary supplements to compensate for the deficiency of these micronutrients in the human body.

Trace elements in the detoxifying and accumulating body parts of Mytilus galloprovincialis Lamark, 1819 (Crimea, Black Sea): human health risks and effect of the sampling site location.

The mussel M. galloprovincialis is one of the most popular species in world's mariculture and environment pollution bioindicators. Although this mollusk was in a focus of numerous publications, the detoxifying and accumulating role of some of its body parts was insufficiently studied. The goals of the present work were as follows: (a) to study the distribution of potentially toxic elements (Cr, Co, Ni, Cu, Zn, As, Cd, Hg, Pb) in soft tissues, byssus, and shell liquor of this bivalve as a function of sampling location in the Black Sea near the southwestern coast of Crimea and (b) to assess human health risks from consuming soft tissues of mussels cultivated on a mollusk farm. Multivariate analysis showed significant differences in the overall distribution of the elements among the body parts and sampling sites under consideration. The trace element contents in soft tissues of M. galloprovincialis decreased in the following order: Zn > Cu > As > Ni > Pb > Cd > Cr > Co > Hg. The noncarcinogenic hazard index from the cultivated mussel consumption was found to be well below one and the carcinogenic risk index was found within the tolerable limits, which indicate the safety of consuming these mussels for humans. Byssus of M. galloprovincialis was characterized as a perfect indicator of marine environment pollution with Ni, Cu, Pb, Сo, and Cr. For the first time, the concentrations of trace elements were determined in the shell liquor and the function of byssus and shell liquor as the systems of trace element excretion from soft tissues was demonstrated.

Heavy Metals and Arsenic in Soft Tissues of the Gastropod Rapana venosa (Valenciennes, 1846) Collected on a Mollusk Farm Off Sevastopol (Southwestern Crimea, Black Sea): Assessing Human Health Risk and Locating Regional Contamination Areas.

The gastropod Rapana venosa is an edible mollusk suitable for biomonitoring of sea shelf contamination. In this work, the contents of five elements (Cu, Zn, As, Cd, Pb) in foot and in the rest of soft tissues of this mollusk were quantified, and the element contents in the edible foot were found below the maximum permissible levels set in several national and transnational regulations. The estimated daily intake of these elements and the hazard index indicated no likely risks to consumers' health, but the long-term cancer risks due to the arsenic intake were found significant. The arsenic and cadmium contents in soft tissues of this rapa whelk were among highest observed in the Black Sea region in the 2010s, and this suggests the specific arsenic and cadmium contamination of seawater off the southwestern Crimea. For the first time, this mollusk was shown to serve as a seawater contamination bioindicator at the regional level.

Dynamics of luminescence characteristics of Haematococcus lacustris cultures in different cultivation conditions.

Luminescence of microalgae cultures is a valuable property for the fast diagnostics of their physiological state; however, it has been rarely used in algaculture practice. In this work, luminescence spectrum characteristics of two-stage batch cultures of the green carotenogenic microalga Haematococcus lacustris (Girod-Chantrans) Rostafinski 1875 (Chlorophyceae, Chlamydomonadales) under conditions of autotrophic and mixotrophic growth were investigated. The dynamics of the heterotrophy indices in cultures at different stages of their development in different growth media was determined. The transition of H. lacustris cultures from the initially autotrophic to mixotrophic growth regime was registered during the induction of the astaxanthin biosynthesis by complex physicochemical stressing, including nutritional deficiencies, exposure to high concentrations of sodium acetate and chloride and increased illuminance and temperature. The applicability of luminescence spectrometry in vivo for a rapid assessment of the state of H. lacustris cultures in various growth media and with different methods of secondary carotenogenesis induction was shown. The results obtained can be used in experimental studies on optimizing cultivation methods for this species, as well as for the express control of the physiological state of its industrial cultures.

Element Contents in Three Commercially Important Edible Mollusks Harvested off the Southwestern Coast of Crimea (Black Sea) and Assessment of Human Health Risks from Their Consumption.

Mollusks are a prospective food for the world's growing population, but the contents of toxic and essential trace elements in them have not been studied comprehensively. In this work, using inductively coupled plasma mass spectrometry, the contents of 72 elements in soft tissues of the edible mollusks Mytilus galloprovincialis, Rapana venosa, and Crassostrea gigas from the coastal area of the southwestern Crimea were estimated and compared with the maximum permissible levels. Element accumulation similarities were observed in the two bivalve species. Cluster analysis applied to the non-normalized contents allowed finding an optimal number of non-overlapping element clusters: 1 group of macroelements, 1-2 groups of trace elements, and 1-2 groups of ultratrace elements. As an outcome of this analysis, the element accumulation universality index was introduced, which demonstrated the accumulation universality decrease in the order: mussel > sea snail > oyster. An original approach to estimating the mollusk consumption rate was proposed to assess human health risks. Two possible consumption scenarios were identified for Crimean residents. From the expected consumption of all species in both scenarios, there are no health risks, but they are not excluded, within the 95% probability, from high consumption of mussels and sea snails in the pessimistic scenario.

Sex- and sexual maturation-related aspects of the element accumulation in soft tissues of the bivalve Mytilus galloprovincialis Lam. collected off coasts of Sevastopol (southwestern Crimea, Black Sea).

Mussels are widely used to monitor trace element pollution, but the role of their sex and sexual maturation in the element accumulation was not comprehensively studied and the number of elements under consideration never exceeded three dozen. In this work, concentrations of 67 elements in different tissues of females and males of the Mediterranean mussel are determined. Statistically significant differences are obtained in the element composition of analogous tissues of mussel males and females and in gonads of the same sex at different sexual maturation stages. The significantly higher concentrations of some elements found in gonads of females (Mn, Zn, As) and males (P) at most of the sexual maturation stages suggest essentiality of these elements in the reproduction. Elements exhibit several accumulation patterns in gonads during the ripening, with the most general one being the accumulation after spawning. Indications of a new phenomenon of circulation of most elements in gonads over the reproductive cycle are obtained, with the element concentrations decreasing at the first two stages and increasing at the posterior stages. Principal component analysis shows that the differences in the element accumulation are mainly due to the element uptake pathways and sexual differentiation. The most important identified factors determining the decrease in concentrations of tissue elements are their redistribution over mussel's body, biomass dilution, sequestration, and release with gametes. Five detected non-overlapping clusters of the non-normalized element concentrations in the pooled mussel tissues are associated with macroelements, two groups of trace elements, and two groups of ultratrace elements.