In situ field experiment shows Lyngbya majuscula (cyanobacterium) growth stimulated by added iron, phosphorus and nitrogen

Ahern, Kathleen S., Ahern, Colin R. and Udy, James W. (2008) In situ field experiment shows Lyngbya majuscula (cyanobacterium) growth stimulated by added iron, phosphorus and nitrogen. Harmful Algae, 7 4: 389-404. doi:10.1016/j.hal.2007.08.006

Author Ahern, Kathleen S.
Ahern, Colin R.
Udy, James W.
Title In situ field experiment shows Lyngbya majuscula (cyanobacterium) growth stimulated by added iron, phosphorus and nitrogen
Journal name Harmful Algae   Check publisher's open access policy
ISSN 1568-9883
Publication date 2008-06
Sub-type Article (original research)
DOI 10.1016/j.hal.2007.08.006
Volume 7
Issue 4
Start page 389
End page 404
Total pages 16
Place of publication Netherlands
Publisher Elsevier BV
Language eng
Formatted abstract
Coastal waters worldwide have experienced an increase in the occurrence of harmful algal blooms. Over the past decade, nuisance blooms of the toxic cyanobacterium Lyngbya majuscula have increased in frequency and severity in south-east Queensland, Australia, with blooms in Moreton Bay hypothesised to be linked to increased inputs of dissolved nutrients and organic carbon from land-based sources. An in situ field experiment was conducted in northern Moreton Bay (Deception Bay), Australia, to determine the growth response of L. majuscula to phosphorus, nitrogen and organically chelated iron additions to the water column. A three-way analysis of variance showed each of these nutrients stimulated L. majuscula biomass under field conditions, with organically chelated iron (FeEDTA) > phosphorus > nitrogen. Concurrent addition of all three nutrients [FeEDTA + P + N] caused the greatest response being 18 times the control after 49 days; this resulted in an additional 928 gdw m−2 of L. majuscula biomass over the control (54 gdw m−2). These results show that water borne nutrients, particularly organically chelated iron, phosphorus and nitrogen can promote prolific growth of the bloom-forming cyanobacterium L. majuscula. It is also likely that the addition of iron and/or phosphorus stimulated nitrogen fixation in L. majuscula, based on the large L. majuscula biomass and higher tissue nitrogen content in the iron and phosphorus treatments. Enrichment with poultry litter (sourced from the adjacent catchment) also substantially enhanced L. majuscula biomass. The experiment shows that a precautionary approach to limit or reduce nutrient additions to streams, estuaries and coastal waters is justified; otherwise the magnitude of L. majuscula blooms is likely to increase in Moreton Bay in the future.
Keyword Algal bloom
Moreton Bay
Lyngbya majuscula
Nitrogen fixation
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Civil Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 18 times in Thomson Reuters Web of Science Article | Citations
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Created: Thu, 03 Sep 2009, 09:58:14 EST by Mr Andrew Martlew on behalf of School of Civil Engineering