Coral bleaching is caused by environmental stress and susceptibility to bleaching stress varies among types of coral. The physiological properties of the algal symbionts (Symbiodinium spp.), especially extent of damage to PSII and its repair capacity, contribute importantly to this variability in stress susceptibility. The objective of the present study was to investigate the relationship between the growth rates and photosynthetic activities of six cultured strains of Symbiodinium spp. (clades A, B, C, D, and F) at elevated temperature (33 °C). We also observed the recovery of photodamaged-PSII in the presence or absence of a chloroplast protein synthesis inhibitor (lincomycin). The growth rates and photochemical efficiencies of PSII (Fv/Fm) decreased in parallel at high temperature in thermally sensitive strains, B-K100 (clade B followed by culture name) and A-Y106, but not in thermally tolerant strains, F-K102 and D-K111. In strains A-KB8 and C-Y103, growth declined markedly at high temperature, but Fv/Fm decreased only slightly. These strains may reallocate energy from growth to the repair of damaged photosynthetic machineries or protection pathways. Alternatively, since recoveries of photo-damaged PSII at 33 °C were modest in strains A-KB8 and C-Y103, thermal stressing of other metabolic pathways may have reduced growth rates in these two strains. This possibility should be explored in future research efforts.

Dinoflagellates from the genus Symbiodinium form symbiotic relationships with many marine invertebrates, including reef-building corals. Symbiodinium is genetically diverse, and acquiring suitable Symbiodinium phylotypes is crucial for the host to survive in habitat environments, such as high-light conditions. The sensitivity of Symbiodinium to high light differs among Symbiodinium phylotypes, but the mechanism that controls light sensitivity has not yet been fully resolved. In the present study using high-light-tolerant and -sensitive Symbiodinium phylotypes, we examined what determines sensitivity to high light. In growth experiments under different light intensities, Symbiodinium CS-164 (clade B1) and CCMP2459 (clade B2) were identified as high-light-tolerant and -sensitive phylotypes, respectively. Measurements of the maximum quantum yield of photosystem II (PSII) and the maximum photosynthetic oxygen production rate after high-light exposure demonstrated that CCMP2459 is more sensitive to photoinhibition of PSII than CS-164, and tends to lose maximum photosynthetic activity faster. Measurement of photodamage to PSII under light of different wavelength ranges demonstrated that PSII in both Symbiodinium phylotypes was significantly more sensitive to photodamage under shorter wavelength regions of light spectra (<470 nm). Importantly, PSII in CCMP2459, but not CS-164, was also sensitive to photodamage under the regions of light spectra around 470-550 and 630-710 nm, where photosynthetic antenna proteins of Symbiodinium have light absorption peaks. This finding indicates that the high-light-sensitive CCMP2459 has an extra component of photodamage to PSII, resulting in higher sensitivity to high light. Our results demonstrate that sensitivity of PSII to photodamage differs among Symbiodinium phylotypes and this determines their sensitivity to high light.

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The status of Indonesian coral reefs are in fair to poor categories, therefore it requires more approaches in order to  recover the natural ecosystem. One of the reef restoration method is coral transplantation. Genus Acropora is one of the main constituent of reefs in the Indo-Pacific waters. Reef transplantation may not only rehabilitate the damaged reef, but also an effective way to collect coral for economic purposes. Acropora secale has high economic value as aquarium ornament, however it is vulnerable to the environmental stress and marine pollution. Therefore, finding the suitable transplantation location is one of important  part in the transplantation. The objective of this research is to investigate the growth of transplant A. Secale at Serangan and Geger Beach which has different morphology feature. A. secale was Transplanted for 3 months on the 2 x 1 m table with 16 fragments and observed each week. The results obtained are total growth and growth rate of A. secale transplanted on Serangan Beach is significant higher than Geger Beach (P<0.05). The total growth of A. secale on Serangan Beach is higher by 0,83 cm, wider by 0,61 cm, and branches are more 7 branches than Geger Beach. The growth rate of A. secale at Serangan Beach was higher by 0,27 cm/month and wider by 0,21 cm/month than Geger Beach. The survival rate of A. secale on Serangan Beach and Geger Beach is 100% which means that all transplanted corals survive until the end of the study.

Tunikata is an animal shaped like a tube and its body is covered by a mantle (tunic). These organisms have functions and impacts for ecology, pharmacology, people and the economy. However, the various important roles of the tunicate are not matched by information on abundance and diversity in Indonesia in general and the island of Bali in particular. Therefore, this study aims to determine the abundance, species composition and the diversity of tunikata in the waters of Jemeluk and Penuktukan, Bali, where each of these waters has a different coral reef morphology reef flats (Jemeluk) and reef slopes (Penuktukan). Data retrieval is done with a 25x2m2 belt transect and parallel to the shoreline. Determination of location of observation based on purposive sampling method. Analysis of the data used using the abundance formula, species composition and the Shannon-Wiener diversity index. The results showed that the abundance of tunikata in Jemeluk waters did not differ significantly between stations where the highest was found in stations 1 and 3, the lowest at station 2. But the abundance of tunicates in waters Penuktukan significantly different between stations where the highest in three and the lowest station on Station 1. There are nine kinds of tunicates on both waters where species Didemnum molle and Atriolum robustum is the type most commonly found. The highest diversity of tunicate species in Jemeluk waters is found in stations 1 and 3 and the lowest is at station 2, while the highest Penuktukan is located at station 1 and the lowest is at station 3. In general, the index of biodiversity in both waters is categorized as low.