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Kelp rafts in the humboldt current: Interplay of abiotic and biotic factors limit their floating persistence and dispersal potential


Rothausler, E and Gomez, I and Hinojosa Toledo, IA and Karsten, U and Miranda, L and Tala, F and Thiel, M, Kelp rafts in the humboldt current: Interplay of abiotic and biotic factors limit their floating persistence and dispersal potential, Limnology and Oceanography, 56, (5) pp. 1751-1763. ISSN 0024-3590 (2011) [Refereed Article]

Copyright Statement

Copyright 2011 by the American Society of Limnology and Oceanography, Inc.

DOI: doi:10.4319/lo.2011.56.5.1751


During summer 2009, we conducted a field experiment and a field survey at 30uS in the coastal Humboldt Current to determine how floating time affects the physiological performance of kelp rafts. For the field experiment kelp rafts were tethered in coastal waters and the field survey was specifically designed to collect freefloating Macrocystis pyrifera across a latitudinal temperature gradient that reflects natural floating time. Experimental kelps were kept under photosynthetic active radiation (PAR) and PAR + ultraviolet (UV; PAR + UV) using filter foils, and tethered at the sea surface in their natural habitat. Ultraviolet radiation (UVR) did not affect kelp physiology, but caused a decrease in kelp biomass. The field survey confirmed that sea-surface temperature increased with distance from upstream source populations of M. pyrifera. Rafts sampled at increasing distance from sources showed high epibiont cover and reduced blade lengths. Physiological performance declined with increasing size of algal epibionts, which are indicators of floating time. Rafts that were farthest from the southern source populations had lost their sporophylls, suggesting that dispersal potential decreases with increasing floating time. The combined effects of abiotic (UVR and temperature) and biotic factors accelerate degradation of M. pyrifera and, thus, can impede successful dispersal in the Humboldt Current at 30uS. This suggests that floating macroalgae can be important dispersal vectors in areas with moderate environmental stress (i.e., in temperate oceans).

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Marine biodiversity
UTAS Author:Hinojosa Toledo, IA (Mr Ivan Hinojosa)
ID Code:88802
Year Published:2011
Web of Science® Times Cited:22
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2014-02-17
Last Modified:2014-07-01

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