Assessing the Influence of Marine Port Remediated Sediments on Highbush Blueberry Growth and Trace Elements Accumulation

The aim of this study was to investigate how biomass production and element distribution (nutrients and heavy metals) among plant organs (roots, stems, and leaves) were influenced by substrate physical and chemical properties, using acidophilic plants of <i>Vaccinium corymbosum</i> cultivars Bluecrop and Duke. A greenhouse pot experiment was conducted with highbush blueberry plants grown in an uncontaminated acidic peat-based control substrate (TS0) and two alkaline substrates enriched with remediated sediment (TS50 and TS100), characterized by high pH, Ca, and heavy metal concentrations. Both plant cultivars that were cultivated in sediment–based substrates exhibited a substantial reduction in plant growth, biomass production, and leaf chlorophyll levels. Limited translocation of microelements from belowground organs to leaves was observed across all plant samples. Cu, Fe, and Pb were predominantly accumulated in the roots of plants grown in TS-based substrates, with both cultivars acting as excluders for these metals by restricting their transport from roots to shoots. Mn and Zn were primarily retained in the stems and roots of highbush blueberry plants, with lower leaf accumulation. Notably, only Mn exhibited high translocation and bioaccumulation factor values (on average, 3.43 and 6.68, respectively), highlighting the species’ strong capacity for Mn accumulation. Specifically, control plants showed significantly higher Mn concentrations than those grown in TS-enriched substrates, likely due to the acidic conditions that enhance the bioavailability of this metal and the low Ca concentration in TS0, which is known to disrupt Mn accumulation in shoots. However, this accumulation did not reach toxic levels for the plants and did not negatively impact the physiological processes of control plants, which remained particularly efficient in the Duke cv, known for its Mn resistance. This study highlights the ability of highbush blueberry plants to selectively accumulate heavy metals when grown in polluted substrates under suitable conditions, making them a valuable model for understanding metal accumulation mechanisms in the Ericaceae family.