Author:
Thomas Marie C.,Flores Florita,Kaserzon Sarit,Fisher Rebecca,Negri Andrew P.
Abstract
AbstractHerbicide contamination of nearshore tropical marine ecosystems is widespread and persistent; however, risks posed by most ‘alternative’ herbicides to tropical marine microalgae remain poorly understood. Experimental exposures of the important but understudied microalgae Rhodomonas salina to seven individual Photosystem II (PSII) inhibitor herbicides (diuron, metribuzin, hexazinone, tebuthiuron, bromacil, simazine, propazine) led to inhibition of effective quantum yield (ΔF/Fm′) and subsequent reductions in specific growth rates (SGR). The concentrations which reduced ΔF/Fm′ by 50% (EC50) ranged from 1.71-59.2 µg L−1, while the EC50s for SGR were 4-times higher, ranging from 6.27-188 µg L−1. Inhibition of ΔF/Fm′ indicated reduced photosynthetic capacity, and this correlated linearly with reduced SGR (R2 = 0.89), supporting the application of ∆F/Fm’ inhibition as a robust and sensitive indicator of sub-lethal toxicity of PSII inhibitors for this microalga. The three non-PSII inhibitor herbicides (imazapic, haloxyfop and 2,4-Dichlorophenoxyacetic acid (2,4-D)) caused low or no toxic responses to the function of the PSII or growth at the highest concentrations tested suggesting these herbicides pose little risk to R. salina. This study highlights the suitability of including R. salina in future species sensitivity distributions (SSDs) to support water quality guideline development for the management of herbicide contamination in tropical marine ecosystems.
Publisher
Springer Science and Business Media LLC
Reference97 articles.
1. Basheer, C., Obbard, J. P. & Lee, H. K. Persistent organic pollutants in Singapore’s coastal marine environment: part I, seawater. Water, Air, Soil Pollut. 149, 295–313, https://doi.org/10.1023/A:1025689600993 (2003).
2. Ali, H. R. et al. Contamination of diuron in coastal waters around Malaysian Peninsular. Mar. Pollut. Bull. 85, 287–291 (2014).
3. Okamura, H., Aoyama, I., Ono, Y. & Nishida, T. Antifouling herbicides in the coastal waters of western Japan. Mar. Pollut. Bull. 47, 59–67 (2003).
4. Roche, H., Salvat, B. & Ramade, F. Assessment of the pesticides pollution of coral reefs communities from French Polynesia. Rev. Ecol. (2011).
5. Sarkar, S. K. et al. Occurrence, distribution and possible sources of organochlorine pesticide residues in tropical coastal environment of India: an overview. Environ. Int. 34, 1062–1071, https://doi.org/10.1016/j.envint.2008.02.010 (2008).
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