The ability of some reef corals to undergo changes in their algal symbiont communities in favor of thermotolerant Symbiodinium is one mechanism by which corals may survive bleaching events and persist into the future despite continued warming. To investigate the dynamics of these unusual symbionts we used a novel transplantation method to experimentally introduce thermotolerant symbionts into healthy corals. We used controlled bleaching at 32oC to remove the ‘native’ Symbiodinium C3 from replicate cores of the Caribbean coral Montastraea cavernosa, and recovered them at 29oC with thermotolerant symbionts (Symbiodinium D1a, aka S. trenchi). These ‘stress hardened’ cores no longer bleached when exposed to 32oC. We then reciprocally transplanted tissue plugs from these manipulated cores into control (unbleached) cores containing C3, and vice versa (N=20 pairs from 5 colonies). The fate of these introduced symbionts, measured in mini-transects across cores using quantitative PCR, was dependent on (1) temperature, with D1a displacing C3 within 3-6 months when maintained at 29oC , but C3 displacing D1a at 22oC; (2) the relative abundance of introduced vs. resident symbionts; and (3) the type of symbiont introduced. As thermotolerant symbionts become more common on disturbed reefs worldwide, these findings help us understand their origin and spread, investigate their relative costs and benefits to reef ecosystems, and consider potential interventions to help reefs survive continued warming.



Baker, A. C., University of Miami, Rosenstiel School of Marine and Atmospheric Science, USA, abaker@rsmas.miami.edu

Jones, P. R., NOAA, Atlantic Oceanographic and Meteorological Laboratory, USA, paul.r.jones@noaa.gov

Winter, R. N., University of Miami, Rosenstiel School of Marine and Atmospheric Science, USA, rwinter@rsmas.miami.edu

Silverstein, R. N., Miami Waterkeeper, USA, rachel@miamiwaterkeeper.org

Cunning, R., Hawaii Institute of Marine Biology, University of Hawaii, USA, ross.cunning@gmail.com


Oral presentation

Session #:05
Date: 06/23/2016
Time: 10:30
Location: 313 B

Presentation is given by student: No