Chances are, you’ve heard of coral bleaching. You probably know that it’s a reaction to stress put upon coral by its environment, and that in severe cases, bleaching can be fatal. But do we know how bleaching occurs?
Actually, we do, and it’s a fascinating story of a symbiotic relationship between organisms. But before we get to this week’s movie…
There’s a word that comes up early in the presentation that passes by rather quickly and deserves some explanation, and that word is “zooxanthellae.”
Zooxanthellae is an algae that normally exists in a symbiotic relationship with coral polyps. Through photosynthesis, zooxanthellae provide coral with oxygen, up to 90 percent of their food, and help remove waste. They also give coral it’s color.
In return, the coral provides zooxanthellae with a safe place to grow, along with nutrients that that the algae need.
When coral is stressed, it expels the zooxanthellae, revealing the coral’s limestone skeleton beneath it’s transparent tissue.
With that out of the way, on with this week’s Friday Night Movie!
