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Mitigating fish-killing algal blooms with PAC modified clays: efficacy for cell flocculation and ichthyotoxin adsorption


Seger, A and Hallegraeff, G, Mitigating fish-killing algal blooms with PAC modified clays: efficacy for cell flocculation and ichthyotoxin adsorption, Proceedings of the 17th International Conference on Harmful Algae 2016, 09-14 October 2016, Florianopolis, Brazil, pp. 154-157. ISBN 9788799082766 (2017) [Refereed Conference Paper]

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Copyright 2017 The International Society for the Study of Harmful Algae.

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Flocculation of harmful algal cells through treatment with modified clay minerals offers great promise in reducing clay loadings required for effective cell removal, yet the ichthyotoxin adsorptive properties of such modified clays have received little attention. We here compare Chattonella marina (raphidophyte) cell removal by conventional (kaolin, bentonite) and polyaluminium chloride (PAC) modified clays (bentonite and Korean loess), while newly exploring the capacity of PAC and PAC modified clays to mitigate C. marina and Alexandrium catenella (dinoflagellate) ichthyotoxicity (quantified with the RTgill-W1 cell line assay). Conventional clays proved ineffective in reducing C. marina cell numbers (145% removal at 0.5 g L-1), but treatment efficacy could be much improved through modification of bentonite and Korean loess with PAC (855% removal at 0.1 g L-1). Ichthyotoxin adsorption by PAC and PAC modified clays proved species specific. While both PAC (0.1 g L-1) and PAC modified clays (0.25 g L-1) could completely eliminate C. marina cytotoxicity, only bentonite clay proved effective in mitigating the negative impact of lysed A. catenella preparations on the gill cell line (6910% gill cell viability). This work highlights how application of modified clays extends beyond improved cell flocculating properties to also include adsorption of selected ichthyotoxins.

Item Details

Item Type:Refereed Conference Paper
Keywords:mitigation, modified clay, ichthyotoxin adsorption, flocculation, fish-killing algae
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Phycology (incl. marine grasses)
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Fisheries - aquaculture not elsewhere classified
UTAS Author:Seger, A (Dr Andreas Seger)
UTAS Author:Hallegraeff, G (Professor Gustaaf Hallegraeff)
ID Code:122355
Year Published:2017
Funding Support:Australian Research Council (DP130102859)
Deposited By:Ecology and Biodiversity
Deposited On:2017-11-10
Last Modified:2018-06-25

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