The response of phytoplankton and microlayer-adapted bacteria to monolayer application in a humic, eutrophic irrigation dam

Pittaway, P. and Matveev, V. (2017) The response of phytoplankton and microlayer-adapted bacteria to monolayer application in a humic, eutrophic irrigation dam. Water Science and Technology, 75 (2). pp. 322-327. ISSN 0273-1223

Abstract

Repeat applications of artificial monolayers to farm irrigation dams to reduce evaporative loss may adversely affect water quality by enhancing populations of microlayer-adapted bacteria and bluegreen algae. The microlayer, subsurface and water column of a 16 ha dam were monitored every two weeks for 18 months, to benchmark the seasonal dynamics of phytoplankton and microlayer-adapted bacteria prior to monolayer application. Results for Secchi depth, total P, total N, chlorophyll a, phytobiovolume and UV254 absorbance, characterise Logan’s Dam as humic and hypereutrophic. Seasonal peaks in the cyanobacterial species Microcystis aeruginosa and Anabaena
sp. associated with regular thermal stratification periods over summer, exceeded the Queensland algal bloom alert level. Dissolved organic matter derived from aromatic char in the black soil used to construct the dam was the main substrate for microlayer-adapted bacteria. Intermittent monolayer application over seven weeks in late summer temporarily increased surface pressure, indicating a
condensed monolayer had formed, with no increase in chemical oxygen demand or in populations of cyanobacteria or microlayer-adapted bacteria. The increase in dissolved organic carbon was well below the concentration recorded after a pump ingress event in late spring. In this humic
hypereutrophic irrigation dam, repeat applications of the experimental monolayer formulation did not adversely affect water quality.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version due to publisher copyright policy.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 06 Mar 2017 00:01
Last Modified: 21 Dec 2017 03:21
Uncontrolled Keywords: cyanobacteria; dissolved organic carbon; mono octadecyl ether; water quality
Fields of Research : 07 Agricultural and Veterinary Sciences > 0799 Other Agricultural and Veterinary Sciences > 079902 Fertilisers and Agrochemicals (incl. Application)
Socio-Economic Objective: D Environment > 96 Environment > 9609 Land and Water Management > 960905 Farmland, Arable Cropland and Permanent Cropland Water Management
Identification Number or DOI: 10.2166/wst.2016.515
URI: http://eprints.usq.edu.au/id/eprint/30510

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