title: Towards a more ecologically relevant assessment of the impact of heavy metals on the photosynthesis of the seagrass, Zostera capricorni.
abstract: This in situ study used photosynthetic activity (measured as chlorophyll a fluorescence) and photosynthetic pigment concentrations to assess the effect of copper, cadmium, lead and zinc on the seagrass Zostera capricorni. Custom-made portable in situ exposure (PIE) chambers were developed so seagrasses could be dosed within the meadow. Z capricorni was exposed to 0.1 and I mg l(-1) of metal solutions for 10 h. During this time and for the subsequent four-day recovery period, the effective quantum yield of photosystem II (PS II) (deltaF/Fm') was measured. While the results were variable, copper and zinc exposed samples had a depressed deltaF/Fm' during the exposure period. Samples exposed to zinc recovered to pre-exposure levels but those exposed to copper did not. Cadmium and lead did not impact on the chlorophyll a fluorescence and the chlorophyll pigment data supported these findings. This study presents an innovative new application of chlorophyll a fluorescence stress assessment.
authors.affiliation: Multiscale Ecosystem Research Group, University of Technology, Sydney, NSW, Australia. cate.macinnis@uts.edu.au
authors.forename: Catriona M O
authors.initials: CM
authors.lastname: Macinnis-Ng
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Ralph
mesh_terms: D001681:Biological Assay; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D019216:Metals, Heavy / Q000009:adverse effects*; D010788:Photosynthesis / Q000187:drug effects*; D018570:Risk Assessment; D014873:Water Pollutants / Q000009:adverse effects*; D035962:Zosteraceae / Q000187:drug effects* / Q000502:physiology*
chemical_list: D019216:Metals, Heavy; D014873:Water Pollutants; D002734:Chlorophyll; D000077194:Chlorophyll A