View article

Recently, there has been a trend toward less turbid water and greater light penetration in parts of western Lake Erie. This could lead to greater phototoxicity from sediment-bound polycyclic aromatic hydrocarbons. To test photosynthesis as a bioindicator of contaminant impacts on algae, water samples containing natural assemblages of phytoplankton were collected from the western and central basins of Lake Erie. These samples were incubated with 0.2 to 2 mg L⁻¹ anthracene or its photomodified product 1,2-dihydroxyanthraquinone for 60 min in darkness or in 50% sunlight, to mimic exposure of phytoplankton in the photic zone of a mixed water column. Photosynthetic efficiency was determined from filtered phytoplankton immediately after exposure using a pulse-amplitude modulated chlorophyll fluorometer. Phytoplankton incubated with chemicals in the dark demonstrated chlorophyll fluorescence values …