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Conditional mutualism between the giant kelp Macrocystis pyrifera and colonial epifauna
Citation
Hepburn, CD and Hurd, CL, Conditional mutualism between the giant kelp Macrocystis pyrifera and colonial epifauna, Marine Ecology Progress Series, 302 pp. 37-48. ISSN 0171-8630 (2005) [Refereed Article]
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Licenced under Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/
Abstract
It is generally considered that colonial invertebrates living on the surfaces of macroalgae
have a negative influence on the growth rates and survivorship of their substratum. To date no
evidence has been provided from natural macroalgal/epifaunal associations to support this view. We
investigated the influence of colonial bryozoans and hydrozoans on the growth rate and nitrogen
physiology of their substratum, the giant kelp Macrocystis pyrifera, and the impact of seasonal
changes of light and the seawater nitrogen concentration on this relationship. Throughout this study
there was no evidence of any negative impact of colonization by either epifaunal group on the growth
of M. pyrifera. During a period of low concentrations of inorganic nitrogen in seawater, the growth of
M. pyrifera fronds heavily colonized by hydroid colonies was higher than less heavily colonized
individuals. During this time hydroids could provide on average between 71 and 122% of the nitrogen
required for uptake by tagged M. pyrifera fronds at ambient seawater nitrogen concentrations.
Evidence suggests that enhanced growth was caused by the provision of ammonium excreted by the
hydroid colonies. Evolutionary pressure to limit the impact of colonization by sessile animals on
macroalgae is likely to be exerted on both the algal substratum and the attached animal. We suggest
that due to their close relationship this pressure may ultimately result in the development of
mutualistic partnerships between algae and specialized sessile seaweed-dwelling fauna in natural
associations.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | kelp, Macrocystic, mutualism, bryozoa, hydrozoa, invertebrate, nitrogen, light |
| Research Division: | Biological Sciences |
| Research Group: | Ecology |
| Research Field: | Ecological physiology |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding knowledge |
| Objective Field: | Expanding knowledge in the agricultural, food and veterinary sciences |
| UTAS Author: | Hurd, CL (Professor Catriona Hurd) |
| ID Code: | 93128 |
| Year Published: | 2005 |
| Web of Science® Times Cited: | 48 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2014-07-14 |
| Last Modified: | 2014-08-05 |
| Downloads: | 620 View Download Statistics |
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