Question

What is a direct cause of coral bleaching?
a.
exposure to sunlight
b.
the loss of symbiotic algae
c.
overgrazing by fish
d.
all of the above

Answer 1

b. the loss of symbiotic algae

Coral bleaching occurs when corals expel or lose their symbiotic algae (zooxanthellae) or the algae lose their pigments, causing the coral to turn white. Environmental stresses (e.g., high temperature, intense sunlight, pollution) trigger this process, but the direct cause is the loss of the algae.