1. Salinity and Coral Bleaching
Group #1
Presentation #1

2. Our Questions?
How does water salinity affect the symbiosis between Xenia polyps and Zooxanthella?
What is the range of water salinity where Xenia Polyps can survive and not bleach?

3. Background
Reduced salinity in the water has been found to be a major leading factor of Coral Bleaching.
This process is believed to happen due to the fact that Corals are “osmoconformers.” This means that corals will gain or loose water to try and keep an isotonic environment around them. This means that when water with low salinity comes near the coral, this organism will intake water to reduce its salt concentration.
This process will end up reducing the amount of “symbiotic dinoflagellates from host tissues,” causing the coral bleaching.

4. Global Warming, Rain and Salinity
There are several factors that can affect the salt concentration in the oceans.
One factor that has been linked with reduced salinity is increased rain fall in cost areas. With higher levels of rain, rivers will also have a higher runoff of water into the ocean decreasing the amount of salt.
Another factor that can affect the salinity of the oceans is the melting of the polar ice caps. It has been found that water with higher salt concentration will move to warmer areas, while low salt concentration will lay near cold water. This means that corals that are located near tropical areas (Caribbean) will exhibit higher salinity, while those coral that lie closer to colder water lower salinity.

5. What do we expect?
As we move farther away form the Xenia polyps natural environment salinity, we believe that more bleaching will occur.
This will probably be caused due to a lost of Zooxanthella and also probably some tissue death.