Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2023

Comparative assessment of accumulation and distribution of metal(loid)s in two saltmarsh halophytes, Austral seablite (Suaeda australis) and Spiny rush (Juncus acutus) (#80)

Md Rushna Alam 1 2 , Thi Kim Anh Tran 1 3 , Mohammad Mahmudur Rahman 4 , Richard Man Kit Yu 1 , Geoff R. MacFarlane 1
  1. School of Environmental and Life Sciences, The University of Newcastle, Callaghan-2308, Newcastle, NSW, Australia
  2. Department of Aquaculture, Patuakhali Science and Technology University, Dumki , Patuakhali-8602, Bangladesh
  3. School of Agriculture and Resources, Vinh University, Nghe An, Viet Nam
  4. Global Centre for Environmental Remediation, The University of Newcastle, Callaghan-2308, Newcastle, NSW, Australia

Despite their huge ecological importance, saltmarsh communities are often exposed to metal(loid)s on both a global and regional scale due to close association with urban and industrial activities. In this context, we compared the pattern of uptake and partitioning of Cu, Zn, Cd, Pb, Se and As between the halophytic saltmarsh species, Austral seablite (Suaeda australis) and Spiny rush (Juncus acutus); collected from the highly urbanised estuaries (Georges river, Sydney Olympic park, Lake Macquarie and Hunter wetlands) of NSW, Australia. We analysed metal(loid)s in the saltmarsh sediment, root and shoot tissues via  ICP-MS. Among the estuaries, the greatest combined sediment metal(loid) load was found in Sydney Olympic park, followed by Lake Macquarie and Georges river, and lowest in Hunter wetlands. Uptake in roots (root BCFs ≥ 1) and subsequent translocation to ariel parts (shoot BCFs ≤ 1) were greater for Cu and Zn in both species, reflecting their metabolic essentiality. Also, higher accumulation of Se in S. australis (root BCF = 1.68, leaf  BCF = 1.87)  and Cd in J. acutus (root BCF = 3.65, culm BCF = 2.83) were evident, implying metal-specific phytoextraction potential for these halophytes. In terms of the accumulation pattern, S. australis exhibited some regulation for Cu, Cd and Se in roots, whereas root Zn, Pb and As was accumulated with environmental dose ( p < 0.05, R2 = 0.15 – 0.59). Conversely, a dose-dependent root uptake was exhibited in J. acutus for all candidate metals as root metals significantly correlated with sediment metals concentration (p < 0.05, R2 = 0.10 – 0.52). The significant positive linear relationships between root and sediment metals indicate, S . australis roots could be useful bioindicators for Zn, Pb and As; J. acutus roots for Cu, Zn, Pb, Cd, Se and As.