I came across this great video of Oysters in the Chesapeake Bay area. The video has underwater shots of areas without and with oyster reefs. The coolest part is towards the end where an oyster blows a “smoke ring”.
As we’ve noted before, oysters are filter feeders. As they filter nutrients out of the water, there are some solids that are rejected (these are called pseudofeces because they are excreted, but they never pass through the gut). When these particle are expelled by the oyster, they swirl through the water and resemble a smoke ring as seen in the video.
What does it all mean? The smoke ring is an indicator that the oysters are filtering algae and other particles out of the water–just doing what they’re meant to do.
Click here to see the video (courtesy of Washington Post and Science Magazine).