Responses of Aquatic Vegetation to Pollution: Preliminary Results on Ecotoxicological Effects and Bioenrichment Factors

Abstract

This study evaluates, on a preliminary basis, the principal morpho-physiological effects induced by pollution stress in four aquatic vegetation species of great ecological relevance in transitional water ecosystems. Three macroalgae (Chaetomorpha linum, Valonia aegagrophyla, Graciliariopsis longissima) and one phanerogams species (Ruppia cirrhosa) were exposed to different doses of trace elements (Cu, Hg, Zn) and surfactants (dodecylbenzenesulfonic acid sodium salt) in laboratory controlled microcosm conditions and morpho-physiological responses (photosynthetic complex alteration, percentage of died cells, morphological changes) were measured before and after 7 and 14 days of exposure. Levels of pollutants in tissues and BioConcentration Factors (BCF) for each species were calculated after 14 days of exposure. Results suggest that photosynthetic complex alteration can be a useful tool to evaluate early and sub-lethal significant changes due to exposure to pollution stress in all of the considered species. A clear species-specificity was observed concerning trace element levels in tissues after 14 days of exposure, while dose-dependent behavior was observed for BCFs.

Biofiltering and Uptake of Dissolved Nutrients by Ulva armoricana (Chlorophyta) in a Land-based Aquaculture System

“…Macroalgae take up inorganic nutrients for growth and can thus alleviate the seasonal nutrient depletion from aquaculture (Chopin et al, 2001;Neori et al, 2004). Several aquaculture research and development efforts have shown the efficiency and benefits of integrating macroalgae in on-land treatment systems for treating aquaculture waste effluents before being discharged into open water bodies (Winberg et al, 2011;Dittert et al, 2012;Renzi et al, 2014).…”

“…Green macroalgae (Chlorophyta) are known to be a significant biological indicator of heavy metal contamination in marine ecosystems (Nelson et al, 2010). Various studies have demonstrated the use of green macroalgae from the genus Ulva as a bio-filter/monitor of coastal contamination because of their relatively simple morphology, high tissue bioaccumulation, and widespread distribution (Alkhalifa et al, 2012;Zoll and Schijf, 2012;Renzi et al, 2014).…”

“…Macroalgae naturally take up elements like Na, K, Ca, Mg, Cl, I and Br from the surrounding water bodies. The major metallic pollutants implicated in culture systems and coastal waters are Pb, Cr, Hg, U, Se, Zn, As, Cd, Au, Ag, Cu and Ni among which Cd is readily absorbed in a combined state with sulphur, chlorine and oxygen and stored in the algal thalli (Komjarova, 2009;Dittert et al, 2012;Renzi et al, 2014). Green macroalgae (Chlorophyta) are known to be a significant biological indicator of heavy metal contamination in marine ecosystems (Nelson et al, 2010).…”