The shores of the Sea of Marmara, to the south of Istanbul, have been blanketed in a thick grey slime that threatens both marine life and the fishing industry.
Experts believe the accumulation of mucilage is connected to untreated waste being dumped into the sea, combined with climate change and warmer waters that cause algae to become overloaded with nutrients.
The coastline of the Marmara is densely populated and home to several industrial sites. President Recep Tayyip Erdoğan said he hopes to “save [the] seas from this mucilage calamity”.
"My fear is, if this expands to Black Sea... the trouble will be enormous. We need to take this step without delay," President Erdoğan said.