Have the tidelands been invaded by zombies?
I've been seeing pale anemones in tidepools; I’ve also been reading about anemones expelling zooxanthellae, the symbiotic algae that give them their bright colors.
Zombie anemones have caught my attention because of the Great Barrier Reef coral bleaching event in the news. According to the University of Google, anemones also bleach for various reasons.
For the past seven months I've observed ghostly anemones in caves (no sunlight for the zooxanthellae to photosynthesize). I've also seen pallid anemones in tidepools with an influx of freshwater (an osmotic emergency for the anemones). But here's the weird thing: I’ve been seeing colorless giant green anemones in direct sunlight with no freshwater runoff.
Could the warm ocean temperatures the Pacific Northwest is experiencing be stressing anemones and causing them to expel their zooxanthellae, leaving them pallid ghosts of their formerly colorful selves?
I came across a study that makes me think my bleaching suspicions aren't completely crazy:
“Our study showed that at least seven of the ten anemone species suffer from bleaching when water temperatures get too high,” said study researcher Ashley Frisch of the ARC Centre of Excellence for Coral Reef Studies at James Cook University. “Importantly, we found bleaching of anemones occurring wherever we looked – from the Red Sea and Indian Ocean to the Indo-Australian region and the Pacific. Sometimes it was on a massive scale.”
Here's another article about anemone bleaching.
Is a major bleaching event along the Oregon Coast on the horizon? No more anemones of vivid green?
As a citizen scientist I will be monitoring changes in the intertidal areas I frequent, looking for zombie anemones that occupy the edge between life and death in the world's warming oceans.