- Title
- Toxicity, growth and accumulation relationships of copper, lead and zinc in the grey mangrove, Avicennia marine (Forsk.) Vierh
- Creator
- Macfarlane, G. R.; Burchett, M. D.
- Relation
- Marine Environmental Research Vol. 54, Issue 1, p. 65-84
- Publisher Link
- http://dx.doi.org/10.1016/S0141-1136(02)00095-8
- Publisher
- Elsevier Science Ltd
- Resource Type
- journal article
- Date
- 2002
- Description
- The effects of three heavy metals Copper (Cu), lead (Pb) and zinc (Zn), and the interaction of an essential (Zn) and non-essential (Pb) metal on germination, growth, and accumulation of metals in the grey mangrove, Avicennia marina (Forsk.) Vierh var. australasica (Walp.) Moldenke, were studied under laboratory conditions. Avicennia marina was found to be highly tolerant to the metals applied. Copper was accumulated in root tissue in a linear relationship at lower sediment concentrations, but at concentrations of 200 μg/g and higher, no further increases in root Cu levels occurred. Translocation of Cu from the root to leaf tissue was low, yet revealed similar accumulation patterns as root tissue. Significant reductions in seedling height leaf number and area were found with significant increases in Cu concentrations in tissues at 100 μg/g sediment Cu. At Cu sediment levels of 400 μg/g, a decrease in total biomass and root growth inhibition was observed. Emergence was retarded with increasing copper concentration, with 800 μg/g sediment Cu resulting in a total inhibition of emergence. The LC₅₀ for emergence and EC₅₀ for biomass was 566 and 380 μg/g Cu respectively. Lead accumulation in root tissue was lower that other metals, yet increased in a dose dependant fashion across the sediment Pb concentration range examined. Lead was excluded from leaf tissue at Pb sediment concentrations up to 400 μg/g, above which limited transport of Pb occurred. Little negative effects on growth were observed due to the low accumulation of Pb. Zinc uptake was high, and was accumulated in a linear fashion in root tissue across the sediment Zn concentration range applied. Zinc translocation to leaf tissue exhibited a dose dependant relationship with both root and sediment Zn levels. Emergence decreased with increasing sediment Zn concentrations, with 1000 μg/g sediment Zn showing 100% mortality. Significant reductions in seedling height, leaf number, area, biomass and root growth inhibition were found at concentrations of 500 μg/g sediment Zn. The LC₅₀ for emergence and EC₅₀ for biomass was 580 and 392 μg/g Zn respectively. Lead and Zn in combination resulted in an increased accumulation of both metals in leaf tissue and increased toxicity than individual metals alone, and is the first noted occurrence of a Pb and Zn additive response in angiosperms. Possible mechanisms of accumulation and toxicity are discussed.
- Subject
- accumulation; Avicennia marina; copper; heavy metals; lead; mangrove; toxicity; zinc
- Identifier
- uon:1428
- Identifier
- http://hdl.handle.net/1959.13/27168
- Identifier
- ISSN:0141-1136
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