Yttrium effects on the Mediterranean mussel under a scenario of salinity shifts and increased temperature

13 pages, 8 figures, 1 table, supplementary data https://doi.org/10.1016/j.marenvres.2024.106365.-- Data availability: Data will be made available on request

Climate change (CC) induces significant worldwide alterations in salinity and temperature, impacting ecosystems and their services. Marine organisms, susceptible to these changes, may experience modified vulnerability to anthropogenic contaminants, including rare-earth elements (REEs) such as yttrium (Y) derived from electronic waste. This study investigated the influence of temperature and salinity changes on the impacts of Y in Mytilus galloprovincialis mussels. Organisms were subjected to Y (0 and 10 μg/L) for 28 days under three salinity scenarios (20, 30 (control), and 40, at a control temperature of 17 °C) or to two temperatures (17 and 22 °C, at the control salinity of 30). Under these conditions, Y bioaccumulation and different biomarkers were evaluated. Results showed that salinity and temperature did not affect Y accumulation, indicating effective detoxification mechanisms and physiological adaptations in the exposed organisms. However, in Y-exposed mussels effects were intensified under decreased salinity, evidenced by increased metabolism, defense enzyme activities, and acetylcholinesterase (AChE) levels. Similar responses occurred under heat stress with enhanced metabolic capacity, AChE activity, and activation of defense mechanisms such as glutathione S-transferases. These defense mechanisms mitigated cellular damage caused by Y, but under the highest temperature and especially lower salinity, Y-exposed mussels exhibited increased oxidative stress and decreased efficiency of activated defense enzymes, resulting in cellular damage compared to their uncontaminated counterpart. The present study sheds light on the effects that interactions between temperature, salinity, and the presence of emerging contaminants like REEs may have on marine organisms. Such assessments are crucial for developing effective strategies to mitigate the impacts of CC and protect the long-term health and resilience of marine ecosystems

Madalena Andrade and João Pinto benefited from Ph.D grants (SFRH/BD/143422/2019 and 2020.05323.BD respectively) funded by National Funds through the Portuguese Science Foundation (Fundação para a Ciência e a Tecnologia, FCT). Thanks are due for the financial support to REQUIMTE and CESAM (UIDB/50006/2020 and UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020, respectively). The authors also acknowledge to the RED RIESCOS - Evaluación de los Efectos de los Contaminantes Emergentes en Organismos Acuáticos y sobre la Salud Humana, from the Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED) with reference 419RT0578 and the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S funded by AEI 10.13039/501100011033)

Peer reviewed