Question

Read the paper by Cunning and Baker (2013)- you can find this paper online to answer. take as much time you need to answer them there is no rush on time thank you

What benefit do corals get from their symbiotic algae?
What is the relationship between water temperature and symbiont density for the species of coral studied? Is there a difference between the C and D clades of Symbiodinium?
What do the authors claim the cue is for coral bleaching? (Hint: it’s not temperature)
Look at figure 3b, in your own words, describe the results are that are depicted in this figure. Do you think this result can be important for developing coral conservation strategies? Why or why not?

Answer 1

1. Corals are dependent upon their symbiotic algae on energy which is produced by symbiotic algae (dinoflagellate algae) by conducting photosynthesis. Corals utilize this energy to form calcium carbonate skeleton to withstand waves in shallow water.

2. In the studied corals P. damicornis, the symbiont cell ratio density increased during increase in temperature or warming, with greater increase in clade-D-dominated colonies and in colonies with lower initial densities. This suggested clade-D is more resilient towards increase in temperature than clade-C.

This study also suggest that corals with high symbionts cell ratio densities are more vulnerable to climate induced bleaching event, as corals bleach more in more warmer conditions.

3. Any environmental stressor that affects symbiont densities, for example ocean acidification as a result of increasing CO₂ and poor water quality can influence coral bleaching.

4.The graph represents the relationship between the change in the total symbiont cell ratio density of clade-C and clade-D before bleaching and during bleaching. The graph suggest that colonies with more symbionts bleached faster especially colonies with clade-C which produced more reactive oxygen species which triggered bleaching. High symbiont cell ratio density with thermo tolerant clade-D also produced cumulatively high reactive oxygen which triggered bleaching.

Yes, these findings can help conservationists to develop strategies to avoid increase in colonies of symbiont at optimal level by reducing the environmental stressors as well as promoting the growth of thermo tolerant species of coral symbiont in controlled conditions.