Impacts of detrital enrichment on estuarine assemblages: disentangling effects of frequency and intensity of disturbance

Bishop, M; Kelaher, BP

Impacts of detrital enrichment on estuarine assemblages: disentangling effects of frequency and intensity of disturbance

Bishop, M Kelaher, BP

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Publisher:: Inter Research
Publication Type:: Journal Article
Citation:: Marine Ecology Progress Series, 2007, 341 pp. 25 - 36
Issue Date:: 2007-01

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Field	Value	Language
dc.contributor.author	Bishop, M	en_US
dc.contributor.author	Kelaher, BP	en_US
dc.date.issued	2007-01	en_US
dc.identifier.citation	Marine Ecology Progress Series, 2007, 341 pp. 25 - 36	en_US
dc.identifier.issn	0171-8630	en_US
dc.identifier.uri	http://hdl.handle.net/10453/3817
dc.description.abstract	Under climate change, enhanced storminess may increase the magnitude and rate of detrital loading to the benthos, potentially altering sediment chemistry and/or physical disturbance of sediments. To assess whether the impact of detrital loading on invertebrates in intertidal sediment sparsely vegetated by seagrass is negatively affected by increasing the frequency and/or intensity of the disturbance, high (90 g dry weight) or low (30 g dry weight) quantities of shredded Zostera capricorm were added to experimental plots at high (intervals of 8 wk, on a total of 3 occasions) or low (added once) frequency. Macroinvertebrate assemblages were sampled 8, 16 and 24 wk after the first detrital enrichment. Plots subjected to frequent detrital addition contained up to 50% fewer macroinvertebrates, representing 50% fewer taxa than plots disturbed only once. This pattern was independent of disturbance intensity and emerged after only 2 detrital additions. Only at the low frequency of addition did the increased quantity of detritus influence macroinvertebrate assemblage composition, halving the number of animals by Week 24. Physical disturbance, not sediment chemistry, drove the frequency effect. Generally negative impacts of frequent detrital enrichment on infaunal populations occurred despite small positive effects of high detrital enrichment on the biomass of microphytobenthos, the food source of many sediment-dwelling invertebrates. These results suggest that, even though climate warming may increase the amount of detritus that is washed up onto intertidal sediments, its greater effect on soft-sediment communities is likely to come through increasing the frequency of storms.	en_US
dc.publisher	Inter Research	en_US
dc.relation.ispartof	Marine Ecology Progress Series	en_US
dc.relation.isbasedon	10.3354/meps341025	en_US
dc.subject.classification	Marine Biology & Hydrobiology	en_US
dc.title	Impacts of detrital enrichment on estuarine assemblages: disentangling effects of frequency and intensity of disturbance	en_US
dc.type	Journal Article
utslib.citation.volume	341	en_US
utslib.for	060205 Marine and Estuarine Ecology (incl. Marine Ichthyology)	en_US
utslib.for	0405 Oceanography	en_US
utslib.for	0602 Ecology	en_US
utslib.for	0608 Zoology	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 the Environment
utslib.copyright.status	open_access
pubs.consider-herdc	true	en_US
pubs.volume	341	en_US

Abstract:

Under climate change, enhanced storminess may increase the magnitude and rate of detrital loading to the benthos, potentially altering sediment chemistry and/or physical disturbance of sediments. To assess whether the impact of detrital loading on invertebrates in intertidal sediment sparsely vegetated by seagrass is negatively affected by increasing the frequency and/or intensity of the disturbance, high (90 g dry weight) or low (30 g dry weight) quantities of shredded Zostera capricorm were added to experimental plots at high (intervals of 8 wk, on a total of 3 occasions) or low (added once) frequency. Macroinvertebrate assemblages were sampled 8, 16 and 24 wk after the first detrital enrichment. Plots subjected to frequent detrital addition contained up to 50% fewer macroinvertebrates, representing 50% fewer taxa than plots disturbed only once. This pattern was independent of disturbance intensity and emerged after only 2 detrital additions. Only at the low frequency of addition did the increased quantity of detritus influence macroinvertebrate assemblage composition, halving the number of animals by Week 24. Physical disturbance, not sediment chemistry, drove the frequency effect. Generally negative impacts of frequent detrital enrichment on infaunal populations occurred despite small positive effects of high detrital enrichment on the biomass of microphytobenthos, the food source of many sediment-dwelling invertebrates. These results suggest that, even though climate warming may increase the amount of detritus that is washed up onto intertidal sediments, its greater effect on soft-sediment communities is likely to come through increasing the frequency of storms.

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http://hdl.handle.net/10453/3817