[Coral-List] Corals-Microbes-Algae

[Mark J A Vermeij]

Dear Coral Listers

Given the recent discussions on this list, I thought the following paper (another "somewhat artificial laboratory study") might be of interest to some of you: 

Vermeij, M.J.A., Smith, J.E., Smith, C.M., Vega Thurber R. and S.A. Sandin (2009) Survival and settlement success of coral planulae: independent and synergistic effects of macroalgae and microbes. Oecologia 159: 325-336.

Abstract:
Restoration of degraded coral reef communities is dependent on successful recruitment and survival of new coral planulae. Degraded reefs are often characterized by high cover of fleshy algae and high microbial densities, complemented by low abundance of coral and coral recruits. Here, we investigated how the presence and abundance of macroalgae and microbes affected recruitment success of a common Hawaiian coral. We found that the presence of algae reduced survivorship and settlement success of planulae. With the addition of the broad-spectrum antibiotic, ampicillin, these negative effects were reversed, suggesting that algae indirectly cause planular mortality by enhancing microbial concentrations or by weakening the coral’s resistance to microbial infections. Algae further reduced recruitment success of corals as planulae preferentially settled on algal surfaces, but later suffered 100% mortality. In contrast to survival, settlement was unsuccessful in treatments containing antibiotics, suggesting that benthic microbes may be necessary to induce settlement. These experiments highlight potential complex interactions that govern the relationships between microbes, algae and corals and emphasize the importance of microbial dynamics in coral reef ecology and restoration.

The paper confirms the ideas behind some of the earlier studies mentioned in the ongoing discussion and simply states that there is additional evidence suggesting a structuring interaction between corals, algae and microbes. I agree that the situation might not necessarily be as evident in the field, but nevertheless it exists.If anyone likes a reprint, please send me an email. Constructive criticism is also welcomed, so we can start thinking about the work required to fine tune this interesting new aspect of coral reef ecology.

Best regards

Mark

__________________________________
Dr. M.J.A. Vermeij
Science Director
Carmabi Foundation
Piscaderabaai z/n
Curaçao, Netherlands Antilles
Phone: +5999-5103067 (NEW NUMBER)
Email: m.vermeij at carmabi.org
Skype: markvermeij
Web: www.carmabi.org

Department of Botany
University of Hawaii at Manoa
email: vermeij at hawaii.edu
http://www.botany.hawaii.edu/