Effects of estimated herbivory on the reproductivepotential of four East African algal species – a mechanismbehind ecosystem shifts on coral reefs?
2007 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 575, no 1, 57-68 p.Article in journal (Refereed) Published
The aim of this field study was toinvestigate effects of estimated fish- and seaurchin herbivory on the reproductive potential offour species of macroalgae; Halimeda macroloba(Decasine), H. renschii (Hauck), Turbinaria ornata(Turner) and Padina boergesenii (Allender etKraft). Fish and sea urchin herbivory were calculatedbased on reported consumption rates fortheir biomass estimates. We hypothesized thatreduced herbivory would increase algal size andthe reproductive potential, which may promotealgal recruitment and be one of the drivingmechanisms behind algal shifts and persistent algae-dominated reefs. Algae were investigated infield sites where the estimated fish- and or seaurchin herbivory differed. Our results suggest thatalgal fecundity of T. ornata and P. boergesenii arepositively correlated to their size. Fecundity ofT. ornata was higher and individuals grew largerin areas where estimated fish herbivory was lower.The two species of Halimeda grew larger andhad higher fecundity in areas where estimatedsea urchin herbivory was lower. P. boergeseniiresponded ambiguously to patterns in herbivory.Due to species-specific responses to differentherbivores, it is difficult to generalize abouteffects of overfishing on algal fecundity.
Place, publisher, year, edition, pages
2007. Vol. 575, no 1, 57-68 p.
Macroalgae, Herbivory, Reproduction, Coral Reefs, Ecosystem change
IdentifiersURN: urn:nbn:se:su:diva-48271DOI: 10.1007/s10750-006-0282-1ISI: 000242505000005OAI: oai:DiVA.org:su-48271DiVA: diva2:374801