Short- and long-term toxicity of nano-sized polyhydroxybutyrate to the freshwater cnidarian Hydra viridissima.

Autor: Santos A; Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal., Oliveira M; CESAM - Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: migueloliveira@ua.pt., Almeida M; CESAM - Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal., Lopes I; CESAM - Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal., Venâncio C; CESAM - Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Mar 20; Vol. 917, pp. 170282. Date of Electronic Publication: 2024 Jan 23.
DOI: 10.1016/j.scitotenv.2024.170282
Abstrakt: The accumulation of increasingly smaller plastic particles in aquatic ecosystems is a prominent environmental issue and is causing a significant impact on aquatic biota. In response to this challenge, biodegradable plastics have emerged as a potential ecological alternative. Nevertheless, despite recent progress in polymer toxicology, there is still limited understanding of the ecological implications of biodegradable plastics in freshwater ecosystems. This study evaluated the toxicity of polyhydroxybutyrate nano-sized particles (PHB-NPLs) on the freshwater cnidarian Hydra viridissima assessing individual and population-level effects. Data revealed low toxicity of PHB-NPLs to H. viridissima in the short-term, as evidenced by the absence of significant malformations and mortality after the 96-h assays. In addition, hydras exhibited rapid and complete regeneration after 96 h of exposure to PHB-NPLs. Feeding assays revealed no significant alterations in prey consumption behavior in the 96-h mortality and malformations assay and the regeneration assay. However, significantly increased feeding rates were observed after long-term exposure, across all tested concentrations of PHB-NPLs. This increase may be attributed to the organisms' heightened energetic demand, stemming from prolonged activation of detoxification mechanisms. These changes may have a cascading effect within the food web, influencing community dynamics and ecosystem stability. Furthermore, a dose-dependent response on the hydras' populational growth was found, with an estimated 20 % effect concentration (EC 20,8d ) on this endpoint of 10.9 mg PHB-NPLs/L that suggests potential long-term impacts on the population's reproductive output and potential depression and local extinction upon long-term exposure to PHB-NPLs on H. viridissima. The obtained data emphasizes the importance of evaluating sublethal effects and supports the adoption of long-term assays when assessing the toxicity of novel polymers, providing crucial data for informed regulation to safeguard freshwater ecosystems. Future research should aim to unravel the underlying mechanisms behind these sublethal effects, as well as the impact of the generated degradation products.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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