The influence of temperature and salinity on the impacts of lead in Mytilus galloprovincialis

Abstract

Mussels, such as the marine bivalve Mytilus galloprovincialis are sentinels for marine pollution but they are also excellent bioindicators under laboratory conditions. For that, in this study we tested the modulation of biochemical responses under realistic concentrations of the toxic metal Lead (Pb) in water for 28 days under different conditions of salinity and temperature, including control condition (temperature 17±1.0 ºC and salinity 30±1.0) as well as those within the range expected to occur due to climate change predictions (±5 in salinity and +4ºC in temperature). A comprehensive set of biomarkers was applied to search on modulation of biochemical responses in terms of energy metabolism, energy reserves, oxidative stress and damage occurrence in lipids, proteins as well as neurotoxicity signs. The application of an integrative Principal Coordinates Ordination (PCO) tool was successful and demonstrated that Pb caused an increased in the detoxification activity mainly evidenced by glutathione Stransferases and that the salinities 25 and 35 were, even in un-exposed mussels, responsible for cell damage seen as increased levels of lipid peroxidation (at salinity 25) and oxidised proteins (at salinity 35).

Combined effects of salinity changes and salicylic acid exposure in Mytilus galloprovincialis

“…In the absence of SA, the obtained results clearly demonstrated that increased salinity levels J o u r n a l P r e -p r o o f better trigger their defence mechanisms against the excess of ROS. Similar findings were observed previously by Freitas et al (2019b) for the same species exposed to similar salinity changes.…”

“…When subjected to environmental changes, such as increases/decreases in salinity and/or the presence of pollutants, organisms often increase their ROS formation with consequent changes on their antioxidant mechanisms of defence. Previous studies already demonstrated that the presence of pollutants such as pharmaceuticals but also changes on salinity levels may induce oxidative stress in marine invertebrates, with alteration on antioxidant enzymes activities, occurrence of cellular damage and loss of redox balance (among others, Franzellitti et al, 2013;Zuccato et al, 2006;Gonzalez-Rey, et al, 2014;Freitas et al, 2019bFreitas et al, , 2019c. In the particular case of SA, previous studies already described increases of antioxidant enzymes and lipid peroxidation levels, suggesting its potential pro-oxidative effect (Doi et al 2002;Doi and Horie 2010), also in non-target organisms (Nunes et al, 2015;Freitas et al, 2019a).…”

The Role of Temperature on the Impact of Remediated Water towards Marine Organisms

“…In the aquatic environment organisms may not only be subject to climate changes but are also exposed to pollutants, such as metals, derived from natural and anthropogenic activities, associated with world population growth [30][31][32][33][34]. Coastal ecosystems have been particularly affected by metals (e.g., lead (Pb), mercury (Hg), cadmium (Cd) and others) with well-known toxic effects towards aquatic organisms [21,[35][36][37][38]. Studies conducted with top list hazardous elements [39] as Hg, Cd and arsenic (As) already showed their capacity to interfere on bivalve's biochemical performance [20,21,[40][41][42][43][44].…”

Toxicological effects of the rare earth element neodymium in Mytilus galloprovincialis

“…Previous studies already demonstrated that the presence of pollutants results into an overproduction of ROS that, if not eliminated by antioxidant enzymes, can react with lipids of the cellular membrane, causing lipid peroxidation that corresponds the oxidative degradation of lipids (see for example, Regoli and Giuliani, 2014). Although a high diversity of studies already showed that the presence of metals, nanoparticles and drugs may originate increased LPO levels in bivalves even if antioxidant enzymes were activated (see for example, Freitas et al, 2019bFreitas et al, , 2019aMcCarthy et al, 2013;Monteiro et al, 2019;Vlahogianni and Valavanidis, 2007), less studies demonstrated the occurrence of LPO when bivalves are exposed REE. In particular, Henriques et al (2019) demonstrated that when M. galloprovincialis were exposed to Gd LPO significantly increased in comparison to control values, although antioxidant enzymes were increased, especially at intermediate concentrations (30 and 60 µg/L).…”