Succession and accrual of benthic algae on cobbles of an upland river following scouring

Davie, AW; Mitrovic, SM; Lim, RP

Succession and accrual of benthic algae on cobbles of an upland river following scouring

Davie, AW Mitrovic, SM

Lim, RP

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Publication Type:: Journal Article
Citation:: Inland Waters, 2012, 2 (2), pp. 89 - 100
Issue Date:: 2012-12-01

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Field	Value	Language
dc.contributor.author	Davie, AW	en_US
dc.contributor.author	Mitrovic, SM https://orcid.org/0000-0002-5528-2215	en_US
dc.contributor.author	Lim, RP	en_US
dc.date.issued	2012-12-01	en_US
dc.identifier.citation	Inland Waters, 2012, 2 (2), pp. 89 - 100	en_US
dc.identifier.issn	2044-2041	en_US
dc.identifier.uri	http://hdl.handle.net/10453/22817
dc.description.abstract	Flow releases from dams can be used to scour benthic algae, simulating the effects of natural spates and maintaining benthic algae in an early successional stage for increased grazer palatability. The timing of releases needs to consider the natural periodicity of flow events and the speed of regrowth and community succession changes. We studied benthic algal regrowth and succession using manipulative field experiments during summer and winter in the upland regulated Severn River, New South Wales, Australia. Benthic algal biomass accrual as chlorophyll a and community changes were determined after artificially scoured cobbles were returned to the river. In summer, algal biomass and diversity on scoured cobbles took 2 weeks to return to levels similar to reference cobbles and 5 weeks in winter. Chlorophyll a during summer was initially 0.24 ± 0.06 mg m-2 on scoured cobbles, but by day 16 had increased to 9.74 ± 1.97 mg m-2 and was no longer significantly different from reference cobbles. In winter, chlorophyll a was initially 0.47 ± 0.13 mg m-2 on scoured cobbles, but by day 37 had increased to 44.7 ± 10.9 mg m-2 and was no longer significantly different from reference cobbles. Peak chlorophyll a accrual during summer and winter was 1.64 and 2.63 mg m-2 d-1, respectively. Early succession in both experiments was dominated by diatoms such as Cocconeis, Synedra, and Fragilaria. A proliferation of the filamentous green alga Stigeoclonium was indicative of a late succession community. The implications for flow management based on resetting of benthic algae by scouring in riffle reaches of rivers are discussed. © International Society of Limnology 2012.	en_US
dc.relation.ispartof	Inland Waters	en_US
dc.relation.isbasedon	10.5268/IW-2.2.441	en_US
dc.title	Succession and accrual of benthic algae on cobbles of an upland river following scouring	en_US
dc.type	Journal Article
utslib.citation.volume	2	en_US
utslib.for	0602 Ecology	en_US
utslib.for	0406 Physical Geography and Environmental Geoscience	en_US
utslib.for	0502 Environmental Science and Management	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Life Sciences
utslib.copyright.status	closed_access
pubs.issue	2	en_US
pubs.publication-status	Published	en_US
pubs.volume	2	en_US

Abstract:

Flow releases from dams can be used to scour benthic algae, simulating the effects of natural spates and maintaining benthic algae in an early successional stage for increased grazer palatability. The timing of releases needs to consider the natural periodicity of flow events and the speed of regrowth and community succession changes. We studied benthic algal regrowth and succession using manipulative field experiments during summer and winter in the upland regulated Severn River, New South Wales, Australia. Benthic algal biomass accrual as chlorophyll a and community changes were determined after artificially scoured cobbles were returned to the river. In summer, algal biomass and diversity on scoured cobbles took 2 weeks to return to levels similar to reference cobbles and 5 weeks in winter. Chlorophyll a during summer was initially 0.24 ± 0.06 mg m-2 on scoured cobbles, but by day 16 had increased to 9.74 ± 1.97 mg m-2 and was no longer significantly different from reference cobbles. In winter, chlorophyll a was initially 0.47 ± 0.13 mg m-2 on scoured cobbles, but by day 37 had increased to 44.7 ± 10.9 mg m-2 and was no longer significantly different from reference cobbles. Peak chlorophyll a accrual during summer and winter was 1.64 and 2.63 mg m-2 d-1, respectively. Early succession in both experiments was dominated by diatoms such as Cocconeis, Synedra, and Fragilaria. A proliferation of the filamentous green alga Stigeoclonium was indicative of a late succession community. The implications for flow management based on resetting of benthic algae by scouring in riffle reaches of rivers are discussed. © International Society of Limnology 2012.

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http://hdl.handle.net/10453/22817