That's what they are apparently...

http://news.yahoo.com/news?tmpl=story&cid=96&e=1&u=/space/20050610/sc_space/giantballsofsnotexplainoceanmystery

Just when you thought it was safe to go back in the water....:D

It appears Mr Sherlock has solved the great mucus mystery. Elementary, my dear Vile...

I like the informal word for them, sinkers lol