A study of the influence of brevetoxin exposure on trace element bioaccumulation in the blue mussel Mytilus edulis

Abstract

Marine organisms are exposed to and affected by a multitude of chemicals present in seawater and can accumulate in their tissues a wide range of contaminants as well as natural biotoxins associated with harmful algal blooms (HABs). Trace elements and biotoxins may modify physiological functions in exposed organisms, and studies have been conducted to better understand their respective kinetics and effects in marine species. Despite the increasing concern of concurrent toxic HABs and pollution events due to anthropogenic pressures and global change, very little information is available on their combined effects. Chemical interactions between biotoxins and trace elements have been reported, and exposure to certain biotoxins is known to modify ion transport pathways, suggesting that biotoxins have the potential to alter trace element uptake. Using specific and sensitive radiotracer techniques (radioligand receptor binding assay and γ-spectrometry), this laboratory study examined the influence of pre-exposure to the brevetoxins (PbTxs)-producing microalgae Karenia brevis on the bioaccumulation of selected non-essential (Cd) and essential (Co, Mn and Zn) trace elements in the blue mussel Mytilus edulis. PbTxs are a group of neurotoxins known to accumulate in bivalves but also to have lethal effects on a number of marine organisms including fish and mammals. We found that, over 23 days exposure to the radiotracers, the bioaccumulation of the dissolved essential trace elements Co, Mn and Zn in M. edulis was not significantly affected by pre-exposure to toxic K. brevis. In contrast, the uptake rate constant ku of Cd was significantly higher in the pre-exposed group (p < 0.05), likely caused by a decrease in mussel clearance rates after K. brevis exposure. These results suggest that the effects of algal toxin exposure on bioaccumulation of trace elements in mussels may be trace elementdependent.

The Effect of Zinc Concentration on Bioaccumulation in Milkfish <i>(Chanos chanos)</i> Use of ⁶⁵Zn as a Radioactive Tracer

“…In contrast, the Cd uptake rate constant was significantly higher in the pre-exposure group, likely due to a decrease in the rate of shellfish clearance after exposure to Karenia brevis algae. These results suggest that the effect of algae toxin exposure on the bioaccumulation of trace elements in shellfish may depend on trace elements [35]. While bioaccumulation modeling and determination of kinetic parameters conducted by Urien [36] explained the first-order kinetic model [37], bioaccumulation of clean water-borne metals can be described with simple biodynamic models and the results of statistical analysis of nonlinear least squares regression following bioaccumulation data.…”

Bioaccumulation of zinc by Portunus pelagicus: Nuclear application techniques that use radiotracer 65Zn to study influence of concentration of Zn in seawater

“…Radioactive tracers are used as labeling of pollutant simulations to make it easier to detect, and research is carried out continuously. Several studies of heavy metal bioaccumulation in various biota using radiotracer techniques have been carried out (Kuranchie-Mensah et al, 2018;McDonald et al, 2020;Pouil et al, 2018;Prihatiningsih et al, 2016).…”