The Sea of Marmara, which lies between the Black and Mediterranean Seas, is covered in mucus:
[A] thick, viscous substance known colloquially as “sea snot” is floating on the water’s surface, clogging up their nets and raising doubts about whether fish found in the inland sea would actually be safe to eat.
Scientists say that the unpleasant-looking mucus is not a new phenomenon, but rising water temperatures caused by global warming may be making it worse. Pollution — including agricultural and raw sewage runoff — is also to blame.
As the Guardian and numerous Turkish news outlets have reported, high levels of nitrogen and phosphorus in the Sea of Marmara, situated between the Black and Aegean Seas, are leading to an explosion of the phytoplankton populations that discharge “sea snot.” Though the mucus itself is not necessarily harmful, it can become a host to toxic microorganisms and dangerous bacteria such as E. coli. And when it forms a layer that covers the water’s surface, it can set off a harmful chain of events, preventing fish from being able to breathe, causing mass die-offs, which in turn leads to plummeting oxygen levels that choke other forms of marine life.
And if you're not up to date on your 16th-century madrigals, the headline of this post comes from this rockin' tune by John Bennett he released way back in '99. (1599.)