In recent news, marine biologists have reported an incredible resurgence in the population of a large clam species known as the noble pen shell, or Pinna nobilis, which was close to disappearing. This clam species faced a severe threat from a deadly disease that spread across parts of the Mediterranean back in 2016, causing a rapid decline in their numbers. Recently, Croatian scientists knew of only around 10 surviving noble pen shells in their Adriatic Sea area. However, in 2022, a diver’s sighting of a group of 20 clams near the north shore of the Istria peninsula astonished experts, sparking disbelief and amazement.

Sandro Dujmovic from the Natura Histrica organization, overseeing Istria’s protected areas, expressed astonishment, stating that the news seemed unbelievable as they thought these clams could not have survived. In 2023, biologists successfully collected around 100 young noble pen shell specimens and transferred them to an aquarium, a positive sign indicating their ability to reproduce. These clams, which can grow up to 4 feet (120 cm) in shell size, play a crucial role in the ecosystem by filtering seawater and supporting other marine organisms’ growth. To ensure their safety and protection, the clams are kept in a specialized environment at the Pula aquarium, free from parasites that can harm them. Biologist Nikolina Premate emphasized the necessity of a pristine environment for the clams to thrive and adapt for their potential return to the sea. Although the exact cause of this resurgence remains unclear, Croatia’s government has allocated funds for further research. Dujmovic underscored the collaborative efforts of various Adriatic coast institutions and individuals engaged in monitoring, exploring, and conserving these clams.