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Effect of temperature and grazing on growth and reproduction of floating Macrocystis spp. (Phaeophyceae) along a latitudinal gradient


Rothausler, E and Gomez, I and Hinojosa Toledo, IA and Karsten, U and Tala, F and Thiel, M, Effect of temperature and grazing on growth and reproduction of floating Macrocystis spp. (Phaeophyceae) along a latitudinal gradient, Journal of Phycology, 45, (3) pp. 547-559. ISSN 1529-8817 (2009) [Refereed Article]

Copyright Statement

Copyright 2009 Phycological Society of America

DOI: doi:10.1111/j.1529-8817.2009.00676.x


Macroalgal rafts frequently occur floating in coastal waters of temperate regions of the world’s oceans. These rafts are considered important dispersal vehicles for associated organisms with direct development. However, environmental factors may limit the floating potential of kelp and thereby the dispersal of associated organisms. To examine the effect of water temperature and grazing on growth, reproductive output, and survival of floating Macrocystis spp., experiments were conducted in outdoor tanks during austral summer 2006 ⁄ 2007 at three sites along the Chilean Pacific coast (20 S, 30 S, 40 S). At each site, Macrocystis spp. was maintained individually at three different water temperatures (ambient, ambient ) 4C, ambient + 4C) and in the presence or absence of the amphipod grazer Peramphithoe femorata for 14 d. High water temperatures (>20C) provoked rapid degradation of Macrocystis spp. rafts. At moderate temperatures (15C–20C), algal survival depended on the presence of associated grazers. In the absence of grazers, algal rafts gained in biomass while grazing caused considerable losses of algal biomass. Algal survival was the highest under cooler conditions (<15C), where raft degradation was slow and grazer-induced biomass losses were compensated by continuing algal growth. Our results indicate that floating kelp rafts can survive for long time periods at the sea surface, but survival depends on the interaction between temperature and grazing. We suggest that these processes limiting the survival of kelp rafts in warmer temperatures may act as a dispersal barrier for kelp and its associated passengers. Key index words: Chile; detachment; floating; grazing; growth; macroalgae; Macrocystis; rafting; reproduction; temperature

Item Details

Item Type:Refereed Article
Keywords:Chile; detachment; floating; grazing; growth, macroalgae, Macrocystis, rafting, reproduction, temperature
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Ecological physiology
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Marine biodiversity
UTAS Author:Hinojosa Toledo, IA (Mr Ivan Hinojosa)
ID Code:88919
Year Published:2009
Web of Science® Times Cited:61
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2014-02-20
Last Modified:2014-06-06

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