This was mentioned by a science-ship-lubbing friend/pirate a few weeks ago, as someone on his ship was looking into the same thing. For some reason, I find it comforting. Maybe you do, too.
Plankton Cool Off With Own Clouds: "DMSP is an important link in the plankton-to-cloud cycle because, as it leaves the phytoplankton cells and enters into the water, bacteria break it down into a chemical called dimethylsulfide, or DMS. Evaporated water, in turn, carries the DMS into the air where the chemical reacts with oxygen to form various sulfur compounds. These compounds collect as dust particles that promote water condensation, which, finally, leads to cloud formation."