File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Response of grazing impacts of an algivorous fish (Pseudogastromyzon myersi: Balitoridae) to seasonal disturbance in Hong Kong streams

TitleResponse of grazing impacts of an algivorous fish (Pseudogastromyzon myersi: Balitoridae) to seasonal disturbance in Hong Kong streams
Authors
KeywordsCyanobacteria
Diatoms
Loach
Periphyton
Spates
Tropical
Issue Date2010
PublisherBlackwell Publishing Ltd. The Journal's web site is located at http://www.blackwellpublishing.com/journals/FWB
Citation
Freshwater Biology, 2010, v. 55 n. 2, p. 411-423 How to Cite?
AbstractManipulative experiments were carried out in four Hong Kong streams (two shaded, two unshaded) to investigate the impact of grazing by an algivorous fish, Pseudogastromyzon myersi, on benthic algal biomass and assemblage composition. Experiments were conducted and repeated during both the dry and wet seasons to determine whether spate-induced disturbance modified any grazing effect. Treatments comprised fish exclusion and inclusion via closed and open cages, with a no-cage treatment used as a control for the cage effect. Treatments were maintained for 4 weeks in each experimental run. 2. Grazing by P. myersi reduced benthic algal biomass and the organic matter content of periphyton in open cages and the no-cage treatment relative to closed cages. The similarity between open-cage and no-cage treatments was evidence that the overall difference among treatments was caused by limiting fish access to closed cages and not merely an artifact of caging. Grazing effects were broadly similar in all streams, but there was a significant statistical interaction between treatments and seasons. 3. Analysis of dry-season data matched the overall trend in inter-treatment differences, confirming the effects of grazing by P. myersi on algal biomass and periphyton organic matter. Significant differences in algal assemblage composition between closed-cage and no-cage treatments during the dry season reflected reductions in the abundance of erect, stalked diatoms (Gomphonema) and filamentous cyanobacteria (Homeothrix). Removal of these vulnerable overstorey algae by P. myersi resulted in greater abundance of understorey diatoms (Achnanthes and Cocconeis) in the no-cage treatment in all streams during the dry season. The composition of algal assemblages in open cages was intermediate between the other two treatments. 4. Although fish densities were greater in all streams during the wet season, spate-induced disturbance obscured grazing effects and there were no significant differences among treatments attributable to fish grazing. Seasonal variation in impacts of P. myersi grazing provides support for the harsh-benign hypothesis, and confirms that biotic factors are less important controls of stream algal biomass and assemblage structure during periods (i.e. the wet season in Hong Kong) when abiotic disturbances are frequent or intense. © 2009 Blackwell Publishing Ltd.
Persistent Identifierhttp://hdl.handle.net/10722/179175
ISSN
2015 Impact Factor: 2.933
2015 SCImago Journal Rankings: 1.574
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorYang, GYen_US
dc.contributor.authorDudgeon, Den_US
dc.date.accessioned2012-12-19T09:52:34Z-
dc.date.available2012-12-19T09:52:34Z-
dc.date.issued2010en_US
dc.identifier.citationFreshwater Biology, 2010, v. 55 n. 2, p. 411-423en_US
dc.identifier.issn0046-5070en_US
dc.identifier.urihttp://hdl.handle.net/10722/179175-
dc.description.abstractManipulative experiments were carried out in four Hong Kong streams (two shaded, two unshaded) to investigate the impact of grazing by an algivorous fish, Pseudogastromyzon myersi, on benthic algal biomass and assemblage composition. Experiments were conducted and repeated during both the dry and wet seasons to determine whether spate-induced disturbance modified any grazing effect. Treatments comprised fish exclusion and inclusion via closed and open cages, with a no-cage treatment used as a control for the cage effect. Treatments were maintained for 4 weeks in each experimental run. 2. Grazing by P. myersi reduced benthic algal biomass and the organic matter content of periphyton in open cages and the no-cage treatment relative to closed cages. The similarity between open-cage and no-cage treatments was evidence that the overall difference among treatments was caused by limiting fish access to closed cages and not merely an artifact of caging. Grazing effects were broadly similar in all streams, but there was a significant statistical interaction between treatments and seasons. 3. Analysis of dry-season data matched the overall trend in inter-treatment differences, confirming the effects of grazing by P. myersi on algal biomass and periphyton organic matter. Significant differences in algal assemblage composition between closed-cage and no-cage treatments during the dry season reflected reductions in the abundance of erect, stalked diatoms (Gomphonema) and filamentous cyanobacteria (Homeothrix). Removal of these vulnerable overstorey algae by P. myersi resulted in greater abundance of understorey diatoms (Achnanthes and Cocconeis) in the no-cage treatment in all streams during the dry season. The composition of algal assemblages in open cages was intermediate between the other two treatments. 4. Although fish densities were greater in all streams during the wet season, spate-induced disturbance obscured grazing effects and there were no significant differences among treatments attributable to fish grazing. Seasonal variation in impacts of P. myersi grazing provides support for the harsh-benign hypothesis, and confirms that biotic factors are less important controls of stream algal biomass and assemblage structure during periods (i.e. the wet season in Hong Kong) when abiotic disturbances are frequent or intense. © 2009 Blackwell Publishing Ltd.en_US
dc.languageengen_US
dc.publisherBlackwell Publishing Ltd. The Journal's web site is located at http://www.blackwellpublishing.com/journals/FWBen_US
dc.relation.ispartofFreshwater Biologyen_US
dc.subjectCyanobacteriaen_US
dc.subjectDiatomsen_US
dc.subjectLoachen_US
dc.subjectPeriphytonen_US
dc.subjectSpatesen_US
dc.subjectTropicalen_US
dc.titleResponse of grazing impacts of an algivorous fish (Pseudogastromyzon myersi: Balitoridae) to seasonal disturbance in Hong Kong streamsen_US
dc.typeArticleen_US
dc.identifier.emailDudgeon, D: ddudgeon@hku.hken_US
dc.identifier.authorityDudgeon, D=rp00691en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1111/j.1365-2427.2009.02290.xen_US
dc.identifier.scopuseid_2-s2.0-74049104779en_US
dc.identifier.hkuros179036-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-74049104779&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume55en_US
dc.identifier.issue2en_US
dc.identifier.spage411en_US
dc.identifier.epage423en_US
dc.identifier.eissn1365-2427-
dc.identifier.isiWOS:000273602500011-
dc.publisher.placeUnited Kingdomen_US
dc.identifier.scopusauthoridYang, GY=26645276500en_US
dc.identifier.scopusauthoridDudgeon, D=7006559840en_US

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats