The effects of temperature and ultraviolet-B (UV-B) on the density of symbiotic dinoflagellates in the gorgonian, Eunicea tourneforti (Milne, Edwards, and Haime) were tested in a controlled laboratory experiment. Four different temperatures (21.5, 26.5, 29, and 31.5°C) and three different UV-B intensities (0.002, 1.50, and 2.80 Wm-2) were used in a fully factorial design. The effect of these treatments on algal symbiont density was monitored over a 35-d treatment period and a 31-d recovery period. Treatment at 31.5°C caused significant decreases in densities of zooxanthellae in coral tissues by the end of the experimental period. While UV-B intensity alone did not cause a significant change in zooxanthellae densities, the 29.0 and 31.5°C with 2.80 Wm-2 treatments had no survivors by day 35. Our results indicate that colonies of E. tourneforti lose a portion of their algal symbiont population upon exposure to temperatures ≥ 29.0°C, and ultraviolet light (UV-B wavelengths of 2.80 Wm-2) exacerbates the stress on the symbiont population, contributing to bleaching.
|Original language||English (US)|
|Number of pages||10|
|Journal||Bulletin of Marine Science|
|State||Published - Sep 2005|
ASJC Scopus subject areas
- Aquatic Science