Red Algae (Rhodophyta) in Biomonitoring of Coastal Ecosystems
Abstract
The formation, species composition and functional role of red algae were studied in the Black Sea’scoastal zone. In sublittoral plant communities, red algae are dominant both by their number of species in the phytocenosis and by their active thallus-the one that ensures their high metabolism. Algae with a large specific surface area of thallus can accumulate heavy metals in higher concentrations. In the paper, we discuss possibilities of using red algae as biomarkers of marine pollution, and as bio filters in the processes of water natural.
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Introduction
Biomonitoring as a system of long-term observations and measures of control over marine environment goes down to two key components: diagnosis and prognosis. When carrying out diagnostic monitoring, we study the "here and now" condition of the ecosystem polluted by the most widespread and hazardous marine contaminants. At that, such monitoring is focused both on environmental factors and on various biological responses that testify to derating of a biotic community'sparameters. Methodology that underlies prognostic monitoring is active experimenting in situ that allows us to cross-relate-within a well-planned study-the results of forecasting environmental implications of existing impacts upon the ecosystem [8]. Recently, the use of biomarkers has taken on special significance for assessing the implications of pollutant effects upon water ecosystems. In seashore ecosystems, algae has a leading role in autotrophic synthesis of organics, as it is precisely algae that determine the biological efficiency level and take part in determining the quality of natural sea water. In this connection, we see that algae'srole is more than logical as monitoring indicators for seashore ecosystems pollution by the most hazardous substances-heavy metals, i.e. pollutants that can get into sea water by many a way. Algae response to heavy metals presence in water is very often the key informant in assessing the marine community condition, if compared to other types of hydrobionts. [4].
It was algae that were there first indicator organisms in qualitative assessments of marine environmental conditions: presence or absence of certain species is a testimony to the environmental status of a water basin. Algae can also be used as biological markers of long-term toxic effects, while their response is what allows us to both forecast changes in the composition of a biotic community and provide well-founded guidance for an active intervention by way of bioremediation and recovery of the affected biocenotic communities before irreversible processes begin in the ecosystem that suffers from anthropogenic impacts [6].
With this in mind, we have carried out studies aimed at providing rationale to the idea of using red algae (with different lifecycles) as biomarkers, when doing biological monitoring of the coastal zone.
The key goal of this study was as follows: to investigate the formation of sublittoral phytocenoses and to determine the specific surface area of red algae'sthallus. Special care was taken for heavy metals distribution in the abiotic component of the ecosystem and for accumulation of the metals in algae of the coastal zone'sbiocenosis. Our findings paved the way for shaping the species composition and subsequent reconstruction of a benthic community on an artificial reef.
Conclusion
The established facts about metal accumulation in sea grass-linked to thallus formation, along with species-and environmentally specific peculiarities of the latter-turn out to be determinative for choosing monitor plants in different taxons and ecological groups in the context of sea ecosystems pollution. This is particularly important for coastal ecosystems that are most susceptible to human impact.
In the sublittoral zone of the sea, red algae belonging to various bottom plant formations play the role of functional dominating species of the biocenosis. High biodiversity of red algae occupying different biotopes in the coastal area is what allows us to use them as indicator/monitor/biomarker-plants when assessing the ecological state of the community when water is contaminated by most dangerous substances. Red algae with a large specific surface area of thallus are capable of accumulating high concentrations of hazardous pollutants including heavy metals. It is exactly this peculiarity that allows to successfully use the algae-along with other types of sea organisms-in bio-filters involved in the processes of self-purification of natural water, relying at that both on the group-specific and selective pattern of heavy metal accumulation [6]. The above statement is based on the following established facts: First, algae provide us with a comprehensive picture of the ecosystem state, which is particularly important when the latter'spollution demonstrates a discreet pattern. Second, algae have an explicit capability of accumulating heavy metals, which both contributes to the accuracy of chemical examinations and indicates that bio-available forms of the former are present in the environment. Third, using algae as monitor plants opens up a promising perspective for developing practical guidance on how to remove heavy metals from polluted water basins via the use of bio-filters implanted in artificial reefs.