It has also been assumed that changing seawater parameters such as pH and temperature will have a significant impact on marine symbionts, potentially altering the diversity, function and community dynamics of their hosts (Galil and Innocenti 1999). For this reasonsymbiontscan be used as a hyper sensibleCC tool for CC in the sea. Thus, one of the research themes will focus on the effect of CC on population dynamics of the swimming crab, Portunuspelagicus, typically found throughout the Indo-Pacific to the coast of Africa, and the epidemiology of selected disease causing organisms. The blue swimming crab is present in large numbers with great value for both recreational and commercial fisheries. Data on the symbionts community of Portunuspelagicus in the NhaTrang Bay area is available and 13 species of symbionts and parasites have so far been identified. Six of those found were in both high prevalence and intensity, while the other 7 are rare. Five of the same 6, are known to have negative impact on host populations (Bristow et al 2011). At 3-5 sampling sites (Cat Ba (HaiPhong), NhaTrang (KhanhHoa) and PhuQuoc (KienGiang) the symbiont community of Portunuspelagicus will be examined and compared. It is expected that the thermal gradient, from North to south, will be reflected in the symbiont community of the different crab populations. The collected data will be used to establish the P. pelagicus/symbionts system as a general field indicator model for CC in coastal waters.
Another research will focus on the effect of acidification caused by CC processes on the host/symbiont system of clown fish and their anemone. Anemonefish (Pomacentridae), lives in tropical and subtropical coral reef areas and have a mutualistic relationship with sea-anemones, upon which they rely for protection. Presently, coral reefs are seriously declining globally and time-lagged effects and increasing CO2 levels mean that rapid further declines are imminent (Munday et al. 2012). Anemone fish are also affected by increasing ocean acidification and it has been shown that increasing pH in the seawater disrupts their sense of smell, impairing their ability to find their specific host sea- anemone (Ha  and Nguyen, 2009, Nguyen et al., 2010, Nguyen and Ha, 2010). By manipulation environmental key parameters for the marine waters, such as seawater acidity and temperature, under controlled laboratory conditions, the changed behavior of the clown fishes will be monitored. The results will provide a fine-tuned model for predicting the consequences for the marine organisms in coral reef areas on changing water conditions.
PD.: Effect of acidification caused by climate change processes on the host/symbiont system of clown fish and their anemone
Ph.D.: Effect of climate change on population dynamics of the swimming crab, Portunuspelagicus, and the epidemiology of selected disease causing organisms