Sediment-algal interactions on intertidal rocky reefs

dc.contributor.authorHurley, Tania Dianne
dc.date.accessioned2009-11-27T02:12:17Z
dc.date.available2009-11-27T02:12:17Z
dc.date.issued2009en
dc.description.abstractMacroalgae are a dominant feature of many rocky intertidal habitats worldwide. An understanding of the processes affecting their growth and survival, especially at early life history stages, is therefore important to an understanding of the structure of rocky intertidal communities. This thesis examines the role that the sediment environment has on habitat-dominating fucoid algae and intertidal community structure. Measurements of sediment flux showed considerable spatial and seasonal variation, while the benthic sediment environment remained relatively stable. Experimental disturbances over 13 months, showed two distinct effects. First, direct effects of sedimentation favoured ephemeral algae and also those with tough thalli. Secondary to this was an alteration of species interactions due to the shifts in community composition. The effect sedimentation has on habitat dominating fucoid algae was also examined with laboratory experiments and outplants of cultured algae. The presence of sediment had a negative effect on the ability of Cystophora torulosa and Hormosira banksii zygotes to attach to the substratum, with even sparse coverings of sediment preventing at least 37% of zygotes attaching to the substratum, and almost a complete recruitment failure with dense coverings of both sand and silt. Sediment and disturbance of turfing communities also influenced early post-settlement survival especially of C. torulosa. Manipulations of the sediment load, nutrient levels and grazer abundance showed the resilience of rocky intertidal communities to the predicted increase in nutrient leaves in coastal waters due to increases anthropogenic intrusion. Most research into the effects of sedimentation have been observational studies and much of the experimental work has been carried out subtidally. My experiments have extended research into the intertidal zone, finding that if sedimentation increases as predicted there will be a consequential loss of habitat dominating fucoid algae and its replacement with sediment tolerant speciesen
dc.identifier.urihttp://hdl.handle.net/10092/3197
dc.identifier.urihttp://dx.doi.org/10.26021/7826
dc.language.isoen
dc.publisherUniversity of Canterbury. Biological Sciencesen
dc.relation.isreferencedbyNZCUen
dc.rightsCopyright Tania Dianne Hurleyen
dc.rights.urihttps://canterbury.libguides.com/rights/thesesen
dc.subjectAlgaeen
dc.subjectSedimenten
dc.subjectKaikouraen
dc.subjectFucoid Algaeen
dc.titleSediment-algal interactions on intertidal rocky reefsen
dc.typeTheses / Dissertations
thesis.degree.disciplineEcologyen
thesis.degree.grantorUniversity of Canterburyen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Scienceen
uc.bibnumber1315319en
uc.collegeFaculty of Scienceen
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