Effects of the presence and absence of various fractions of dissolved organic matter on the toxicity of fenvalerate toDaphnia magna

Valerie A. Hodge; Gary T. Fan; Keith R. Solomon; Narinder K. Kaushik; Gary G. Leppard; B. Kent Burnison

doi:10.1002/etc.5620120117

Effects of the presence and absence of various fractions of dissolved organic matter on the toxicity of fenvalerate toDaphnia magna

Environmental Toxicology and Chemistry ◽

10.1002/etc.5620120117 ◽

1993 ◽

Vol 12 (1) ◽

pp. 167-176 ◽

Cited By ~ 13

Author(s):

Valerie A. Hodge ◽

Gary T. Fan ◽

Keith R. Solomon ◽

Narinder K. Kaushik ◽

Gary G. Leppard ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Presence And Absence

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Facilitated Heterogeneous Photodegradation of Dissolved Organic Matter by Particulate Iron

Environmental Chemistry ◽

10.1071/en04005 ◽

2004 ◽

Vol 1 (3) ◽

pp. 197 ◽

Cited By ~ 9

Author(s):

Julia A. Howitt ◽

Darren S. Baldwin ◽

Gavin N. Rees ◽

Barry T. Hart

Keyword(s):

Organic Matter ◽

Iron Oxide ◽

Dissolved Organic Matter ◽

Iron Oxides ◽

Aquatic Ecosystems ◽

Photochemical Reactions ◽

Freshwater Systems ◽

Particulate Iron ◽

Presence And Absence ◽

Australian Freshwater

Environmental Context. Iron oxides, as suspended minerals or as a colloidal phase, are common in Australian freshwater systems. Freshwater systems are also loaded with carbon-based substances, ‘dissolved organic matter’, but not all is biologically available as food to freshwater organisms. However, photochemical interactions between these iron oxides and dissolved organic matter provide a mechanism for biologically resistant carbon to re-enter the food web. Suspended iron oxides thus need to be considered in carbon cycles in aquatic ecosystems. Abstract. The photochemical degradation of dissolved organic matter (DOM) derived from the leaves of River Red Gum (Eucalyptus camaldulensis) was examined, with a particular focus on the photochemical generation of CO2, consumption of O2, and the effect of particulate iron minerals on these photochemical reactions. Solutions of leaf leachate were irradiated with ultraviolet and visible light in the presence and absence of amorphous iron oxides. Addition of fresh iron oxide was found to increase the rate of photodegradation of the organic matter by up to an order of magnitude compared to the reactions without added iron oxide. The ratio of CO2 produced to O2 consumed was ~1:1 in both the presence and absence of iron oxyhydroxide. The reactivity of the iron oxides was dependent on the preparation method and decreased with increased storage time. These results suggest that photochemical reactions on particle surfaces should be considered when examining carbon transformation in aquatic ecosystems, especially at sites with potential for the production of iron oxyhydroxides.

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The effects of dissolved organic matter from a native and an invasive plant species on juvenile Daphnia survival and growth

Journal of Plankton Research ◽

10.1093/plankt/fbaa027 ◽

2020 ◽

Vol 42 (4) ◽

pp. 453-456

Author(s):

Keiko W Wilkins ◽

Erin Overholt ◽

Craig Williamson

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Invasive Plant ◽

Aquatic Organisms ◽

Secondary Compounds ◽

Red Maple ◽

Negative Effects ◽

Survival And Growth ◽

Presence And Absence

Abstract Shifts in the composition of terrestrial plant communities could have significant effects on freshwater zooplankton due to changes in the quality of inputs of terrestrially derived dissolved organic matter (DOM). Leachate from native red maple (RM) and invasive Amur honeysuckle (AH) were used to explore the effects of DOM source on survival and growth of juvenile Daphnia ambigua. Prior research with both terrestrial and aquatic organisms indicates that AH-derived DOM has negative effects. Comparing bioassays in the presence and absence of algae with no additional DOM, RM- or AH-derived DOM, RM had stronger negative effects on both Daphnia survival and growth while AH only decreased growth. The negative effects seen in the presence and absence of algae provided evidence for both indirect and direct effects due to phytotoxicity and plant secondary compounds, respectively. DOM source may play a key role in regulating consumers in aquatic ecosystems.

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