Lipid peroxidation in Spartina alterniflora in relation to anthropogenic particles (APs) and sediment conditions in the Bahía Blanca Estuary, Argentina.

Coastal salt marshes are dynamic ecosystems exposed to multiple natural and anthropogenic stressors, yet their combined effects on plant physiological responses remain poorly understood under field conditions. This study evaluated lipid peroxidation (LPO) in above- and belowground organs of Spartina alterniflora from the Bahía Blanca Estuary (Argentina), integrating seasonal variability, sediment physicochemical characteristics, anthropogenic particles (APs) in sediments and associated with aboveground organs, sediment metal concentrations, and plant structural traits (above- and belowground biomass, plant height, and stem number). LPO levels were consistently higher in aboveground than belowground organs across seasons, with no significant seasonal variation, suggesting that oxidative damage was primarily associated with organ-specific physiological processes rather than environmental fluctuations. Although sediment physicochemical parameters and AP abundance exhibited seasonal patterns, no consistent associations with LPO were observed. However, a positive correlation of marginal statistical significance between sediment APs and belowground LPO was detected during summer, whereas APs associated with aboveground organs were not related to LPO. Multivariate analyses revealed patterns of covariation among sediment AP levels, LPO, and plant structural traits, whereas APs associated with aboveground organs exhibited a different pattern of variation. Metal concentrations showed limited relationships with LPO, and ordination analyses suggested that sediment AP accumulation and Pb enrichment may be influenced by distinct environmental drivers. Overall, these findings indicate that oxidative responses in S. alterniflora reflect a complex interplay of intrinsic and environmental factors, highlighting the potential of LPO as a biomarker while emphasizing the importance of considering intrinsic plant characteristics in salt marsh biomonitoring.