Synergistic, antagonistic, and additive effects of heavy metals (copper and cadmium) and polycyclic aromatic hydrocarbons (PAHs) under binary and tertiary combinations in key habitat-forming kelp species of Chile

• Published in: Environmental science and pollution research international Vol. 28; no. 14; pp. 18300 - 18307
• Main Authors: Meynard, Andrés, Espinoza-González, Camila, Núñez, Alejandra, Castañeda, Francisco, Contreras-Porcia, Loretto
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2021; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Cadmium; Cell walls; Chile; Coastal environments; Contaminants; Copper; Earth and Environmental Science; Ecosystem; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fossil fuels; Germination; Heavy metals; Kelp; Metals, Heavy; Polycyclic Aromatic Hydrocarbons; Short Research and Discussion Article; Species; Spores; Toxicants; Toxicity; Waste Water Technology; Water Management; Water Pollutants, Chemical; Water Pollution Control; Chile; Combined toxicity effects; Polycyclic aromatic hydrocarbons (PAHs); Kelps; Early life stages; Heavy metals; Binary and tertiary mixtures
• DOI: 10.1007/s11356-021-13261-6
• ISSN: 0944-1344

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) are persistent toxicants in coastal environments. Notably, in comparison to individual metal toxicity, knowledge about the effects of HMs and PAHs mixtures on kelps remains scarce. Accordingly, we performed in vitro experiments to determine the individual and combined effects of Cu, Cd, and PAHs on spore release, settlement, and germination on Macrocystis pyrifera and Lessonia spicata , two key-habitat forming kelp species of the coast of the Valparaíso Region in Chile. This region concentrates highly polluting industries, mainly due to unrestrained mining and fossil-fuel energy production. Single Cu, Cd, and PAHs treatments included concentrations in the ranges 5–200, 0.125–2000, and 0.05–100 μg/L, respectively, and a toxic-free treatment. Cu, Cd, and PAHs concentrations causing 20–50% (IC20, IC50) arrested spore release, settlement, and germination were determined, and the results shown in both species that single Cu, Cd, and PAHs IC20 values were generally lower on spore release than on spore settlement and germination, probably due to the absence of a cell wall in spores compared to later stages. Binary equitoxic IC20s mixture treatments changed from an antagonistic response to another with a greater inhibitory effect on spore release, from hour 1 to 7, whereas in IC50 treatments, the response was always antagonistic. The tertiary IC20 mixture of Cu+Cd+PAHs produced generally an antagonistic effect. Remarkably, all IC20 equitoxic mixture treatments showed a synergistic response on spore settlement in both kelps, suggesting that these toxicants are extremely harmful to kelp population persistence near highly polluted sites.