Trace metal concentrations in the tropical sponge Spheciospongia vagabunda at a sewage outfall: synchrotron X-ray imaging reveals the micron-scale distribution of accumulated metals |
| |
Authors: | Anna Padovan Niels Munksgaard Belinda Alvarez Keith McGuinness David Parry Karen Gibb |
| |
Institution: | 1. Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT, 0909, Australia 2. Arafura Timor Research Facility, Australian Institute of Marine Science, Darwin, NT, 0810, Australia 3. Museum and Art Gallery of the Northern Territory, Darwin, NT, 0801, Australia
|
| |
Abstract: | Major and trace elements were measured in sponges, seawater and sediment in Darwin Harbour (Australia) to test the hypothesis
that metals are elevated in sponges closer to a sewage outfall compared with unimpacted sites. Seawater and sediment at the
sewage discharge site contained high, but localised, concentrations of phosphorus (P), manganese (Mn), iron (Fe), cobalt (Co),
nickel (Ni), copper (Cu), zinc (Zn), arsenic (As) and lead (Pb) compared with background sites. Metal concentrations in the
sponge Spheciospongia vagabunda were highly elevated compared with other sponges and, although site specific, high metal concentrations were unrelated to
the presence of sewage effluent. X-ray fluorescence microprobe imaging was used to investigate the metal distribution pattern
in S. vagabunda. High Fe, Ni and Zn concentrations were either localised in circular patches (100–200 μm size) near water canals or in the
pinacoderm, or scattered in spots (approximately 10 μm) throughout the tissue. This supports a microflora-mediated metal bioaccumulation
hypothesis. In contrast, Co and Mn were highly dispersed and probably associated with aluminium- and iron-oxide rich sediment
inclusions. Although the lack of association between sewage effluent and metal accumulation precludes the use of S. vagabunda as a biomonitor, the apparent differential mechanisms of metal accumulation warrants further investigation. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|