The noble pen shell, scientifically known as Pinna nobilis and colloquially as the fan mussel, has experienced a remarkable surge in population in the Marmara Sea. This increase signifies the species’ own triumph and presents a promising solution to the pervasive mucilage problem.

The mucilage problem experienced in the Marmara Sea in 2021 threatened the existence of many organisms in the marine ecosystem, particularly the noble pen shell.

Mustafa Sarı, a scientist studying its effects, considers these fan mussels essential for restoring the Marmara Sea ecosystem as they can filter seawater. Sarı initiated the "Hope Pinna" project in collaboration with Borusan Holding. The project aims to increase the population of pen shells, listed as an endangered species in the Mediterranean Sea.

To observe the results of the project, Sarı and his team identified 80 subregions along the 150-kilometer (90-mile) coastline of the Marmara Sea and scanned an area of 30,000 square meters by conducting more than 200 dives.

Stating that the results were even more positive than expected, Sarı noted that the mass deaths of pen shells that started before the mucilage invasion in the sea have stopped.

"Pinna has started to appear everywhere in the Marmara Sea, and their presence is significantly higher than the global average. We have determined that a dense population is living healthily," he said.

Representatives from cities with coastlines on the Marmara Sea, the Agriculture and Forestry Ministry, the Environment, Urbanization and Climate Change Ministry, and nongovernmental organizations, as well as many scientists, recently gathered in Balıkesir at the "Marmara’s Hope Pinnas Project Conservation Strategy" event to further explore the mollusk's potential.