Since late December, the Sea of Marmara in the northwest corner of Turkey has slowly been invaded, reports The Guardian. Now the invasion has reached the Turkish coastline, and the guilty party? Sea snot.

A mucus excreted by phytoplankton, “sea snot,” looks like a “creamy, gelatinous blanket of quicksand,” according to The Guardian. The mucus has disrupted coastal activity from fishing to hunting to tourism.

  • The current bloom is the largest one ever seen in Turkey, according to The Science Times, and the first one seen in nearly 15 years.

What is ‘sea snot’ and why is it invading?

Sea snot is not a new phenomenon. Phytoplankton excretes the mucus under the right conditions, said The Guardian. The thick, viscous mucus collects in a blanket along the surface of the water.

The ongoing sea snot invasion is particularly extensive for three reasons:

  1. Scientists say rising water temperatures due to global warming have contributed to the increased frequency of these sea snot events, reports The Washington Post. With a mild winter this year, the Sea of Marmara has remained a few degrees warmer than average.
  2. Phytoplankton thrives in waters rich in nutrients of nitrogen and phosphorous. The Sea of Marmara has high levels of both due to pollution from raw sewage dumping and agricultural runoff, reports Forbes.
  3. Overfishing in the Sea of Marmara has reduced the number of filter feeders, fish that eat phytoplankton and keep populations under control, says The Guardian.

So what? What’s the worst that could happen?

In small amounts, sea snot is not particularly harmful. In extreme amounts, such as the current invasion, the mucus can set off a problematic chain of events, says The Washington Post.

For humans, the sea snot makes fishing and dive hunting difficult or impossible. According to The Guardian, some fishermen along the Marmara coastline have not been able to work since the mucus appeared. The mucus may also discourage tourism.

For marine life, the sea snot can set off a devastating chain of events that reduces the amount of oxygen in the water or clogs the gills of underwater animals, leading to mass die-offs, and further imbalance to the marine ecosystem, says The Science Times and The Washington Post.

  • The mucus can sink to the seafloor where it covers and suffocates marine life such as corals, says The Guardian.

The sea snot invasion in the Sea of Marmara currently poses a severe threat to the underwater ecosystem. Workers have already collected and incinerated 110 tons of sea snot from the Sea of Marmara, according to The Washington Post.